Mechanistic Studies on the Wacker Oxidation
|
|
|
- Clifton Quentin Patrick
- 6 years ago
- Views:
Transcription
1 2 + 2 Cu II 2 2 Cu I C C C II 0 II 4 Mechanistic Studies on the Wacker xidation 3 C Pamela Tadross Stoltz Group Literature Presentation ecember 8, PM, 147 Noyes II II II 3 II ,
2 rigins of the Wacker xidation F. C. Phillips, 1894: 4 + C (0) + C 3 C Phillips, F. C. Am. Chem. J. 1984, 16, Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, S.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80.
3 rigins of the Wacker xidation F. C. Phillips, 1894: 4 + C (0) + C 3 C Smidt, Wacker Chemie, 1959: (0) + 2 Cu Cu Cu + 1/ Cu Phillips, F. C. Am. Chem. J. 1984, 16, Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, S.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80.
4 rigins of the Wacker xidation 4 + C (0) + C 3 C (0) + 2 Cu Cu Cu + 1/ Cu Phillips, F. C. Am. Chem. J. 1984, 16, Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, S.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80.
5 rigins of the Wacker xidation 4 + C (0) + C 3 C (0) + 2 Cu Cu Cu + 1/ Cu C /2 2 C 3 C Net Result: Air oxidation of ethylene to acetaldehyde! Phillips, F. C. Am. Chem. J. 1984, 16, Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, S.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80.
6 rigins of the Wacker xidation 4 + C (0) + C 3 C (0) + 2 Cu Cu Cu + 1/ Cu C /2 2 C 3 C Net Result: Air oxidation of ethylene to acetaldehyde!! First organopalladium reaction applied on industrial scale.! First rendered commercial in 1960.! At one point was responsible for the production of over 2 billion pounds per year of acetaldehyde! Phillips, F. C. Am. Chem. J. 1984, 16, Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, S.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80.
7 rigins of the Wacker xidation 4 + C (0) + C 3 C (0) + 2 Cu Cu Cu + 1/ Cu C /2 2 C 3 C Net Result: Air oxidation of ethylene to acetaldehyde!! First organopalladium reaction applied on industrial scale.! First rendered commercial in 1960.! At one point was responsible for the production of over 2 billion pounds per year of acetaldehyde!! Prior acetaldehyde production: a) xymercuration of acetylene b) ehydrogenation of ethanol! Wacker process eventually replaced because of more efficient ways of producing acetic acid (i.e. Monsanto process). Phillips, F. C. Am. Chem. J. 1984, 16, Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, S.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80.
8 Early Kinetic Studies Conditions: [ II ] = M [ ] = M [ + ] = M Rate = d[c 2 4 ] dt = k [ 4 ] [C 2 4 ] [ ] 2 [ + ]! First order in II! Second order inhibition! First order acid inhibition enry, P. M. J. Am. Chem. Soc. 1964, 86, Jira, R.; Sedlmeier, J.; Smidt, J. Liebigs Ann. Chem. 1966, 693, 99. Moiseev, I. I.; Vargaftik, M. N.; Syrkin, Ya. K. okl. Akad. Nauk. SSSR 1963, 153, 140.
9 Early Kinetic Studies Chloride Inhibition Conditions:! First order in II [ II ] = M [ ] = M [ + ] = M Rate = d[c 2 4 ] dt = k [ 4 ] [C 2 4 ] [ ] 2 [ + ]! Second order inhibition! First order acid inhibition Source of Chloride Inhibition: + C [ ] inhibition [ ] inhibition enry, P. M. J. Am. Chem. Soc. 1964, 86, Jira, R.; Sedlmeier, J.; Smidt, J. Liebigs Ann. Chem. 1966, 693, 99. Moiseev, I. I.; Vargaftik, M. N.; Syrkin, Ya. K. okl. Akad. Nauk. SSSR 1963, 153, 140.
10 Early Kinetic Studies Proton Inhibition Conditions: [ II ] = M [ ] = M [ + ] = M Rate = d[c 2 4 ] dt = k [ 4 ] [C 2 4 ] [ ] 2 [ + ]! First order in II! Second order inhibition! First order acid inhibition 2 C 2 C 2 2 uter-sphere hydroxide attack: Predicted to be 10 3 times faster than diffusion controlled process enry, P. M. J. Am. Chem. Soc. 1964, 86, Jira, R.; Sedlmeier, J.; Smidt, J. Liebigs Ann. Chem. 1966, 693, 99. Moiseev, I. I.; Vargaftik, M. N.; Syrkin, Ya. K. okl. Akad. Nauk. SSSR 1963, 153, 140.
11 Early Kinetic Studies Proton Inhibition Conditions: [ II ] = M [ ] = M [ + ] = M Rate = d[c 2 4 ] dt = k [ 4 ] [C 2 4 ] [ ] 2 [ + ]! First order in II! Second order inhibition! First order acid inhibition 2 C 2 C 2 2 uter-sphere hydroxide attack: Predicted to be 10 3 times faster than diffusion controlled process 2 2 C 2 C uter-sphere water attack: Predicted to occur by an anti hydroxypalladation mechanism enry, P. M. J. Am. Chem. Soc. 1964, 86, Jira, R.; Sedlmeier, J.; Smidt, J. Liebigs Ann. Chem. 1966, 693, 99. Moiseev, I. I.; Vargaftik, M. N.; Syrkin, Ya. K. okl. Akad. Nauk. SSSR 1963, 153, 140.
12 Early Kinetic Studies Proton Inhibition Conditions: [ II ] = M [ ] = M [ + ] = M Rate = d[c 2 4 ] dt = k [ 4 ] [C 2 4 ] [ ] 2 [ + ]! First order in II! Second order inhibition! First order acid inhibition 2 C 2 C 2 2 uter-sphere hydroxide attack: Predicted to be 10 3 times faster than diffusion controlled process 2 2 C 2 C uter-sphere water attack: Predicted to occur by an anti hydroxypalladation mechanism C 2 C 2 2 Inner-sphere hydroxyl attack: Predicted to occur by a syn hydroxypalladation mechanism enry, P. M. J. Am. Chem. Soc. 1964, 86, Jira, R.; Sedlmeier, J.; Smidt, J. Liebigs Ann. Chem. 1966, 693, 99. Moiseev, I. I.; Vargaftik, M. N.; Syrkin, Ya. K. okl. Akad. Nauk. SSSR 1963, 153, 140.
13 Kinetic Isotope Effects Early Evidence for an Inner-Sphere Syn ydroxypalladation Mechanism C 3 C + (0) (0) k k = 1.07 enry, P. M. J. rg. Chem. 1973, 38, Kosaki, M.; Isemura, M.; Kitaura, K.; Schinoda, S.; Saito, Y. J. Mol. Catal. 1977, 2, 351. Saito, Y.; Schinoda, S. J. Mol. Catal. 1980, 9, 461.
14 Kinetic Isotope Effects Early Evidence for an Inner-Sphere Syn ydroxypalladation Mechanism C 3 C + (0) (0) k k = 1.07 KIE for decomposition step determined by competitive isotope effect experiment: -shift 2 C ( 2 ) 2 k k = shift 2 C enry, P. M. J. rg. Chem. 1973, 38, Kosaki, M.; Isemura, M.; Kitaura, K.; Schinoda, S.; Saito, Y. J. Mol. Catal. 1977, 2, 351. Saito, Y.; Schinoda, S. J. Mol. Catal. 1980, 9, 461.
15 Kinetic Isotope Effects Early Evidence for an Inner-Sphere Syn ydroxypalladation Mechanism outer-sphere anti hydroxypalladation KIE 1.07 and competitive KIE of 1.70 indicates that the slow step occurs before decomposition C 2 C C C 2 C 2 inner-sphere syn hydroxypalladation enry, P. M. J. rg. Chem. 1973, 38, Kosaki, M.; Isemura, M.; Kitaura, K.; Schinoda, S.; Saito, Y. J. Mol. Catal. 1977, 2, 351. Saito, Y.; Schinoda, S. J. Mol. Catal. 1980, 9, 461.
16 Kinetic Isotope Effects Early Evidence for an Inner-Sphere Syn ydroxypalladation Mechanism outer-sphere anti hydroxypalladation KIE 1.07 and competitive KIE of 1.70 indicates that the slow step occurs before decomposition C 2 C fast slow C + 2 slow 2 C 2 C 2 fast inner-sphere syn hydroxypalladation anti pathway has decomposition as the slow step syn pathway has hydroxypalladation as the slow step enry, P. M. J. rg. Chem. 1973, 38, Kosaki, M.; Isemura, M.; Kitaura, K.; Schinoda, S.; Saito, Y. J. Mol. Catal. 1977, 2, 351. Saito, Y.; Schinoda, S. J. Mol. Catal. 1980, 9, 461.
17 Kinetic Isotope Effects Early Evidence for an Inner-Sphere Syn ydroxypalladation Mechanism outer-sphere anti hydroxypalladation KIE 1.07 and competitive KIE of 1.70 indicates that the slow step occurs before decomposition C 2 C C + 2 slow 2 C 2 C 2 fast inner-sphere syn hydroxypalladation anti pathway has decomposition as the slow step syn pathway has hydroxypalladation as the slow step enry, P. M. J. rg. Chem. 1973, 38, Kosaki, M.; Isemura, M.; Kitaura, K.; Schinoda, S.; Saito, Y. J. Mol. Catal. 1977, 2, 351. Saito, Y.; Schinoda, S. J. Mol. Catal. 1980, 9, 461.
18 Early Stereochemical Studies Stille's Work Suggests Anti ydroxypalladation Mechanism 2 Na 2 C 3 C Key: C insertion proceeds with retention of stereochemistry at the migrating stereocenter. Stille, J. K. J. rganomet. Chem. 1976, 108, 401. Stille, J. K.; ivakarumi, R. J. J. rganomet. Chem. 1979, 169, 239.
19 Early Stereochemical Studies Stille's Work Suggests Anti ydroxypalladation Mechanism 2 Na 2 C 3 C Key: C insertion proceeds with retention of stereochemistry at the migrating stereocenter. C C anti hydroxypalladation syn hydroxypalladation Stille, J. K. J. rganomet. Chem. 1976, 108, 401. Stille, J. K.; ivakarumi, R. J. J. rganomet. Chem. 1979, 169, 239.
20 Early Stereochemical Studies Stille's Work Suggests Anti ydroxypalladation Mechanism 2 Na 2 C 3 C anti hydroxypalladation Stille, J. K. J. rganomet. Chem. 1976, 108, 401. Stille, J. K.; ivakarumi, R. J. J. rganomet. Chem. 1979, 169, 239.
21 Early Stereochemical Studies Stille's Work Suggests Anti ydroxypalladation Mechanism 2 Na 2 C 3 C anti hydroxypalladation Criticism:! lefin is unable to rotate into the square plane of the 2 making syn hydroxypalladation impossible! Ligand exchange to give (cod)( 2 ) would result in a cationic intermediate and is unlikely Stille, J. K. J. rganomet. Chem. 1976, 108, 401. Stille, J. K.; ivakarumi, R. J. J. rganomet. Chem. 1979, 169, 239.
22 Early Stereochemical Studies Stille's Work Suggests Anti ydroxypalladation Mechanism 2 Na 2 C 3 C anti hydroxypalladation 2 L n C L n L n C L n Stille, J. K. J. rganomet. Chem. 1976, 108, 401. Stille, J. K.; ivakarumi, R. J. J. rganomet. Chem. 1979, 169, 239.
23 Early Stereochemical Studies Stille's Work Suggests Anti ydroxypalladation Mechanism 2 Na 2 C 3 C anti hydroxypalladation 2 L n C L n L n C L n Stille, J. K. J. rganomet. Chem. 1976, 108, 401. Stille, J. K.; ivakarumi, R. J. J. rganomet. Chem. 1979, 169, 239.
24 Early Stereochemical Studies Stille's Work Suggests Anti ydroxypalladation Mechanism Criticism:! Solvent is acetonitrile not water.! Might proceed through a dimeric complex.! C (3 atm) is very coordinating and might occupy coordination sites prohibiting the ligation of water necessary for syn hydroxypalladation. anti hydroxypalladation 2 L n C L n L n C L n Stille, J. K. J. rganomet. Chem. 1976, 108, 401. Stille, J. K.; ivakarumi, R. J. J. rganomet. Chem. 1979, 169, 239.
25 Bäckvall's Stereochemical Studies Further (More Convincing) Evidence for uter-sphere Anti ydroxypalladation [ ] < 1 M [Cu 2 ] < 1 M 3 C loss of stereochemical information C Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
26 Bäckvall's Stereochemical Studies Further (More Convincing) Evidence for uter-sphere Anti ydroxypalladation [ ] < 1 M [Cu 2 ] < 1 M 3 C loss of stereochemical information C [ ] > 3 M [Cu 2 ] > 2.5 M C 3 C + stereochemical information retained (maybe) Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
27 Bäckvall's Stereochemical Studies Further (More Convincing) Evidence for uter-sphere Anti ydroxypalladation [ ] < 1 M [Cu 2 ] < 1 M 3 C loss of stereochemical information C [ ] > 3 M [Cu 2 ] > 2.5 M C 3 C + stereochemical information retained (maybe) Two Key Assumptions:! Chlorohydrin and acetaldehyde form from the same intermediate (i.e., [(C 2 C 2 )( 2 ) 2 ] ).! The steric course of the reaction is not affected by conditions containing high [ ] and high [Cu 2 ]. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
28 Bäckvall's Stereochemical Studies Further (More Convincing) Evidence for uter-sphere Anti ydroxypalladation C 2 C Cu Cu decomposition C 3 C! Chloride displacement of occurs with inversion of stereochemistry at carbon.! Chlorohydrin formation requires both high [ ] and high [Cu 2 ]. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
29 Bäckvall's Stereochemical Studies Further (More Convincing) Evidence for uter-sphere Anti ydroxypalladation Cu 2 anti hydroxypalladation Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
30 Bäckvall's Stereochemical Studies Further (More Convincing) Evidence for uter-sphere Anti ydroxypalladation Cu 2 anti hydroxypalladation Cu 2 syn hydroxypalladation Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
31 Bäckvall's Stereochemical Studies Further (More Convincing) Evidence for uter-sphere Anti ydroxypalladation Cu 2 anti hydroxypalladation Cu 2 syn hydroxypalladation Control Experiments:! Z/E isomerization is < 1% under the reaction conditions.! Cofirmed that cleavage of C bond with Cu 2 occurs with inversion at carbon.! Confirmed that chlorohydrin does not arise from an intermediate epoxide. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
32 Bäckvall's Stereochemical Studies An Apparent Contradiction with KIE Studies outer-sphere anti hydroxypalladation KIE 1.07 and competitive KIE of 1.70 indicates that the slow step occurs before decomposition fast C 2 C slow C + 2 slow 2 C 2 C 2 fast innter-sphere syn hydroxypalladation anti pathway has decomposition as the slow step syn pathway has hydroxypalladation as the slow step enry, P. M. J. rg. Chem. 1973, 38, Kosaki, M.; Isemura, M.; Kitaura, K.; Schinoda, S.; Saito, Y. J. Mol. Catal. 1977, 2, 351. Saito, Y.; Schinoda, S. J. Mol. Catal. 1980, 9, 461.
33 Bäckvall's Stereochemical Studies Reconciling Stereochemical Results with Kinetic ata C 2 C Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
34 Bäckvall's Stereochemical Studies Reconciling Stereochemical Results with Kinetic ata C 2 C C 2 C 2 slow 2 C 2 C Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
35 Bäckvall's Stereochemical Studies Reconciling Stereochemical Results with Kinetic ata C 2 C C 2 C 2 slow 2 C 2 C Since decomposition occurs after the rate-limiting step a primary isotope effect would not be predicted. 2 C 2 C 2 fast 2 2 C C 3 3 C Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Chem. Soc., Chem. Commun. 1977, 264. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, 2411.
36 Evidence for Syn ydroxypalladation The Isomerization of Allyl Alcohol Under Wacker Conditions k 1 k 1 k 1 II k 1 k 2 oxidation products xidation of allyl alcohol is directed by the hydroxyl group Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
37 Evidence for Syn ydroxypalladation The Isomerization of Allyl Alcohol Under Wacker Conditions k 1 k 1 k 1 II k 1 If hydroxypalladation is anti, isomerization should occur since hydroxypalladation is required to be an equilibrium process. k 2 oxidation products If hydroxypalladation is syn, isomerization should not occur since hydroxypalladation is rate limiting. xidation of allyl alcohol is directed by the hydroxyl group Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] 2 [ + ] Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
38 Evidence for Syn ydroxypalladation The Isomerization of Allyl Alcohol Under Wacker Conditions k 1 k 1 II k 1 k 1 If hydroxypalladation is anti, isomerization should occur since hydroxypalladation is required to be an equilibrium process. k 2 oxidation products If hydroxypalladation is syn, isomerization should not occur since hydroxypalladation is rate limiting. xidation of allyl alcohol is directed by the hydroxyl group Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] 2 [ + ] Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
39 Evidence for Syn ydroxypalladation The Isomerization of Allyl Alcohol Under Wacker Conditions k 1 k 1 II k 1 k 1 If hydroxypalladation is anti, isomerization should occur since hydroxypalladation is required to be an equilibrium process. k 2 oxidation products If hydroxypalladation is syn, isomerization should not occur since hydroxypalladation is rate limiting. Isomerization product was < 3% of the total deuterated allyl alcohol when the reaction was stopped after one half-life. ydroxypalladation is NT an equilibrium process! Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
40 Evidence for Syn ydroxypalladation The Isomerization of Allyl Alcohol Under Isomerization Conditions [ ] = 3.3 M k 1 k 1 II k 1 k 1 If hydroxypalladation is anti, isomerization should occur since hydroxypalladation is required to be an equilibrium process. k 2 oxidation products If hydroxypalladation is syn, isomerization should not occur since hydroxypalladation is rate limiting. Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] nly isomerization observed. Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
41 Evidence for Syn ydroxypalladation The Isomerization of Allyl Alcohol Under Isomerization Conditions [ ] = 3.3 M k 1 k 1 II k 1 k 1 Reactions at high and low chloride do not proceed through the same mechanism. Formation of aldehyde and chlorohydrin does not occur through a common hydroxypalladation intermediate. If hydroxypalladation is anti, isomerization should occur since hydroxypalladation is required to be an equilibrium process. k 2 oxidation products If hydroxypalladation is syn, isomerization should not occur since hydroxypalladation is rate limiting. Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] nly isomerization observed. Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
42 Anti ydroxypalladation at igh [ ] enry's Proposed Pathway C 2 C C outer-sphere anti hydroxypalladation C 2 C C Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
43 Anti ydroxypalladation at igh [ ] enry's Proposed Pathway C 2 C C outer-sphere anti hydroxypalladation C 2 C C Gregor, N.; enry, P. M. J. Am. Chem. Soc. 1981, 103, 681.
44 Reinterpreting Bäckvall's Results enry's Proposed Pathway 4 + C ligand loss prevented by high concentration of. + 2 C 2 C 2 Excess prevents this intermediate from undergoing decomposition to oxidation products. outer-sphere anti hydroxypalladation C 2 C 2 Cu 2 Assumption that oxidation products and chlorohydrin arise from a common intermediate is NT valid. Gregor, N.; Zaw, K.; enry, P. M. rganometallics 1984, 3, 1251.
45 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe F 3 C F 3 C 3 C F 3 C C 3 3 C C 3 Required Properties:! Substrate cannot undergo oxidation; can only isomerize. oxidation products! Substrate whose RLS is hydroxypalladation.! Substrate possesses stereochemistry that can be used to distinguish between syn and anti hydroxypalladation. oxidation products Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
46 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe F 3 C F 3 C 3 C F 3 C C 3 3 C C 3 k 1 k 1 k 1 k 1 oxidation products II F 3 C oxidation products 3 C C 3 Exchange is completely symmetric, thus the rate of isomerization depends only on the rate of formation of the hydroxypalladate and not on its equilibrium concentration. Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
47 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe F 3 C F 3 C 3 C F 3 C C 3 3 C C 3 k 1 k 1 k 1 k 1 oxidation products II F 3 C oxidation products 3 C C 3 For syn hydroxypalladation: For anti hydroxypalladation: Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] 2 [ + ] Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] Proton inhibition term must result from an equilibrium that occurs before the rate-limiting hydroxypalladation step. Proton inhibition term does not show up in the exchange rate because it results from this exchange equilibrium. Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
48 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe F 3 C F 3 C 3 C F 3 C C 3 3 C C 3 k 1 k 1 k 1 k 1 oxidation products II F 3 C oxidation products 3 C C 3 For syn hydroxypalladation: Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] 2 [ + ] Proton inhibition term must result from an equilibrium that occurs before the rate-limiting hydroxypalladation step. bserved Kinetics under Wacker Conditions:! Rate expression had a first order proton inhibition term.! Rate expression was identical to the Wacker rate expression.! Consistent with syn hydroxypalladation mechanism. Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
49 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe F 3 C F 3 C 3 C F 3 C C 3 3 C C 3 k 1 k 1 k 1 k 1 oxidation products II F 3 C oxidation products 3 C C 3 bserved Kinetics under igh [ ] Conditions:! Rate expression had no first order proton inhibition term.! Rate expression was identical to what Bäckvall observed at high [ ].! Consistent with anti hydroxypalladation mechanism. For anti hydroxypalladation: Rate = d[c 2 4 ] dt = k [ 4 ] [olefin] [ ] Proton inhibition term does not show up in the exchange rate because it results from this exchange equilibrium. Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
50 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z F 3 C C 3 C 3 4 (R), E 2 Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
51 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z F 3 C C 3 C 3 4 (R), E 2 + syn F 3 C II C 3 C II 2 F 3 C C 3 C 3 (S), E Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
52 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z product F 3 C C 3 C 3 4 substrate config % ee [ ] [catalyst] % isomerization % S % R (R), E 2 R R S S syn F 3 C II C 3 C II 2 F 3 C C 3 C 3 (S), E Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
53 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z product F 3 C C 3 C 3 4 substrate config % ee [ ] [catalyst] % isomerization % S % R (R), E 2 R R S S syn F 3 C II C 3 C II 2 F 3 C C 3 C 3 (S), E Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
54 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z F 3 C C 3 C substrate config % ee [ ] % Z % isomerization % S % R R R product (R), E S S syn F 3 C II C 3 C II 2 F 3 C C 3 C 3 (S), E Francis, J. W.; enry, P. M. rganometallics 1992, 11, 2832.
55 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z F 3 C C 3 C substrate config % ee [ ] % Z % isomerization % S % R R R product (R), E S S syn F 3 C II C 3 C II 2 F 3 C C 3 C 3 (S), E Francis, J. W.; enry, P. M. rganometallics 1992, 11, 2832.
56 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe high [ ] anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z F 3 C C 3 C 3 4 Conclusions:! At low [ ] (Wacker conditions), syn hydroxypalladation is operative. (R), E 2! At high [ ] (Bäckvall's conditions), anti hydroxypalladation is operative. low [ ] + syn F 3 C II C 3 C II 2 F 3 C C 3 C 3 (S), E Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
57 Evidence for Syn ydroxypalladation A New Stereochemical and Kinetic Probe high [ ] anti + F 3 C II C 3 C II 2 3 C C 3 (R), Z Criticism: F 3 C C 3 C 3 4! Trisubstituted alkenes are not standard Wacker substrates.! Substrate cannot undergo oxidation. (R), E 2! Would be best to study a substrate that can undergo both oxidation and isomerization under both low and high [ ] concentrations. low [ ] + syn F 3 C II C 3 C II 2 F 3 C C 3 C 3 (S), E Francis, J. W.; enry, P. M. rganometallics 1991, 10, 3498.
58 Chirality Transfer Studies R 2 R 1 (R), Z reactive conformation amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, 7745.
59 Chirality Transfer Studies [ ] > 2 M R 2 anti II 2 (S), Z R 1 R 2 R R 2 II R 1 [ ] = 0.1 M 0 + R 2 (S) R 1 2 (R), Z reactive conformation amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, 7745.
60 Chirality Transfer Studies [ ] > 2 M R 2 anti II 2 (S), Z R 1 R 2 R R 2 II R 1 [ ] = 0.1 M 0 + R 2 (S) R 1 (R), Z reactive conformation 2 + R 2 R 1 [ ] > 2 M II 2 R 2 R 1 (R), E syn II [ ] = 0.1 M R 2 R amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, (R)
61 Chirality Transfer Studies [ ] > 2 M R 2 anti II 2 (S), Z R 1 R 2 R R 2 II R 1 [ ] = 0.1 M 0 + R 2 (S) R 1 (R), Z reactive conformation 2 + R 2 R 1 [ ] > 2 M II 2 R 2 R 1 (R), E syn II [ ] = 0.1 M R 2 R amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, (R)
62 Chirality Transfer Studies [ ] > 2 M Me Ph Me Me (R), Z reactive conformation Ph Me anti + + Me Me II Ph Me Me II 2 [ ] = 0.1 M 0 + [ ] > 2 M II 2 Me Me (S), Z Me Ph Me (S) Me Ph (R), E syn II Ph [ ] = 0.1 M Me Me 0 + amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, (R) Ph
63 Chirality Transfer Studies [ ] > 2 M Me Ph Me Me (R), Z reactive conformation Ph Me anti + + Me Me II Ph must add syn regardless of the [ ] Ph Me Me II 2 [ ] = 0.1 M 0 + [ ] > 2 M II 2 Me Me (S), Z Me Ph Me (S) Me Ph (R), E syn II Ph [ ] = 0.1 M Me Me 0 + amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, (R) Ph
64 Chirality Transfer Studies [ ] > 2 M Me Me Et 4 anti + Me II Et II 2 [ ] = 0.1 M 0 + Et (S), Z Me Et (S) (R), Z reactive conformation 2 + Me Et [ ] > 2 M II 2 Me Et (R), E syn II [ ] = 0.1 M Me Et 0 + amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, (R)
65 Me Et (R), Z reactive conformation 4 2 Chirality Transfer Studies anti + + Me Me II Et Et [ ] > 2 M II 2 [ ] = 0.1 M [ ] > 2 M II 2 Me Me (S), Z Me 0 + the stereochemistry of hydroxypalladation(s) must be different at high and low [ ] (R), E Et Et Et syn II [ ] = 0.1 M Me Et 0 + amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, (R)
66 Me Et (R), Z reactive conformation 4 2 Chirality Transfer Studies anti + + Me Me II Et Et [ ] > 2 M II 2 [ ] = 0.1 M II 2 Me (S), Z (R), E 0! Excess prevents syn hydroxypalladation + by Et prohibiting the ligation of water. (S)! Excess prevents "-hydride elimination to oxidation products by prohibiting the necessary dissociation of a ligand. [ ] > 2 M Me Et Me Et syn II [ ] = 0.1 M Me Et 0 + amed,.; enry, P. M.; Thompson, C. J. rg. Chem. 1999, 64, (R)
67 Mechanism for xidation of lefins under Wacker Conditions 1 [ ] inhibition 1 [ ] inhibition 2 C C C + Cu [ + ] inhibition syn hydroxypalladation enry, P. M. In andbook of rganopalladium Chemistry for rganic Synthesis; Negishi, E.-I., Ed.; John Wiley & Sons, Inc.: New York, 2002; Vol. 1, p 2119.
68 Mechanism for xidation of lefins under Wacker Conditions 1 [ ] inhibition 1 [ ] inhibition 2 C C C + Cu [ + ] inhibition syn hydroxypalladation enry, P. M. In andbook of rganopalladium Chemistry for rganic Synthesis; Negishi, E.-I., Ed.; John Wiley & Sons, Inc.: New York, 2002; Vol. 1, p 2119.
69 Mechanism for ecomposition to xidation Products Moiseev's Mechanism:!-hydride elimination dissociation tautomerize Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, J.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80. Moiseev, I. I.; Warhaftig, M. N.; Sirkin, J.. oklady Akad. Nauk UdSSR 1960, 130, 820. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, enry, P. M. J. Am. Chem. Soc. 1964, 86, 3246.
70 Mechanism for ecomposition to xidation Products Moiseev's Mechanism:!-hydride elimination dissociation tautomerize C + (0) C + (0) lack of proton incorporation from solvent means that tautomerization mechanism is invalid Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, J.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80. Moiseev, I. I.; Warhaftig, M. N.; Sirkin, J.. oklady Akad. Nauk UdSSR 1960, 130, 820. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, enry, P. M. J. Am. Chem. Soc. 1964, 86, 3246.
71 Mechanism for ecomposition to xidation Products enry's Model + (0) + II -assisted hydride shift Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, J.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80. Moiseev, I. I.; Warhaftig, M. N.; Sirkin, J.. oklady Akad. Nauk UdSSR 1960, 130, 820. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, enry, P. M. J. Am. Chem. Soc. 1964, 86, 3246.
72 Mechanism for ecomposition to xidation Products enry's Model + (0) + II -assisted hydride shift Bäckvall's Model!-hydride elimination reinsertion + (0) +!-hydride elimination from oxygen Smidt, J.; afner, W.; Jira, R.; Sieber, R.; Sedlmeier, J.; Sabel, A. Angew. Chem. Int. Ed. Engl. 1962, 1, 80. Moiseev, I. I.; Warhaftig, M. N.; Sirkin, J.. oklady Akad. Nauk UdSSR 1960, 130, 820. Bäckvall, J.-E.; Åkermark, B.; Ljunggren, S.. J. Am. Chem. Soc. 1979, 101, enry, P. M. J. Am. Chem. Soc. 1964, 86, 3246.
73 Mechanism for ecomposition to xidation Products Computational Studies Bäckvall's Model 3 C II + (0) +!-hydride elimination from oxygen Goddard's Computations Keith, J. A.; xgaard, J.; Goddard, W. A., III J. Am. Chem. Soc. 2006, 128, Keith, J. A.; Nielsen, R. J.; xgaard, J.; Goddard, W. A., III J. Am. Chem. Soc. 2007, 129,
74 Mechanism for ecomposition to xidation Products Computational Studies Bäckvall's Model II 3C + (0) +!-hydride elimination from oxygen Goddard's Computations 4-membered TS: 36.3 kcal/mol Keith, J. A.; xgaard, J.; Goddard, W. A., III J. Am. Chem. Soc. 2006, 128, Keith, J. A.; Nielsen, R. J.; xgaard, J.; Goddard, W. A., III J. Am. Chem. Soc. 2007, 129,
75 Mechanism for ecomposition to xidation Products Computational Studies Bäckvall's Model II 3C + (0) + β-hydride elimination from oxygen Goddard's Computations 4-membered TS: 36.3 kcal/mol -mediated reductive elimination TS: 18.7 kcal/mol Keith, J. A.; xgaard, J.; Goddard, W. A., III J. Am. Chem. Soc. 2006, 128, Keith, J. A.; Nielsen, R. J.; xgaard, J.; Goddard, W. A., III J. Am. Chem. Soc. 2007, 129,
76 From Industrial Process to Synthetic Method Preparations of Methyl Ketones from Terminal lefins ement, 1964: 2 (10 mol%) oxidant 2 (12-17%), 2 MF oxidant = Cu (10 mol%) or p-benzoquinone ement, W..; Selwitz, C. M. J. rg. Chem. 1964, 29, 241. Tsuji, J. Synthesis 1984, 369.
77 From Industrial Process to Synthetic Method Preparations of Methyl Ketones from Terminal lefins ement, 1964: 2 (10 mol%) oxidant 2 (12-17%), 2 MF oxidant = Cu (10 mol%) or p-benzoquinone Me Me Zearalenone 19-Nortestosterone intermediate to ichroanone TP Nootkatone Brevicomin intermediate to Coriolin ement, W..; Selwitz, C. M. J. rg. Chem. 1964, 29, 241. Tsuji, J. Synthesis 1984, 369.
78 Moritani, 1973: From Industrial Process to Synthetic Method xidative Cyclizations Give Access to eterocyclic Compounds R Na + 2 (PhCN) 2 (1 equiv) Ph R osokawa, T.; Maeda, K.; Koga, K.; Moritani, I. Tetrahedron Lett. 1973, 10, 739.
79 Moritani, 1973: From Industrial Process to Synthetic Method xidative Cyclizations Give Access to eterocyclic Compounds R Na + 2 (PhCN) 2 (1 equiv) Ph R (dba) 2 (5 mol%) KC 3 (1.1 equiv) (Ac) 2 (2 mol%) Cu(Ac) 2 2 (1 equiv) air, MS, 2 60 C air, MF, 100 C no co-oxidant! Roshchin, A. I.; Kel'chevski, S. M.; Bumagin, N. A. J. rganomet. Chem. 1998, 560, 163. Larock, R. C.; Wei, L.; ightower, T. R. Synlett 1998, 522.
80 Moritani, 1973: From Industrial Process to Synthetic Method xidative Cyclizations Give Access to eterocyclic Compounds R Na + 2 (PhCN) 2 (1 equiv) Ph R (dba) 2 (5 mol%) KC 3 (1.1 equiv) (Ac) 2 (2 mol%) Cu(Ac) 2 2 (1 equiv) air, MS, 2 60 C air, MF, 100 C no co-oxidant! (TFA) 2 (10 mol%) ligand (20 mol%) p-benzoquinone (4 equiv) Me, 60 C 96% ee i-pr N N i-pr Uozumi, Y.; Kato, K.; ayashi, T. J. rg. Chem. 1998, 63, 5071.
81 From Industrial Process to Synthetic Method xidative Cyclizations Give Access to eterocyclic Compounds Me 2 C Boc N Bn Bn Bn N NTs N N Ts N osokawa, T.; Murahashi, S.-I. In andbook of rganopalladium Chemistry for rganic Synthesis; Negishi, E.-I., Ed.; John Wiley & Sons: New York, 2002; Vol. 2, pp
82 Stereochemistry of xidative Cyclizations L n R anti oxypalladation R R Ln!-hydride elimination R L n syn oxypalladation R R Ln!-hydride elimination
83 Stereochemistry of xidative Cyclizations Stoltz Group Studies (TFA) 2 (5 mol%) pyridine (20 mol%) Na 2 C 3 (2 equiv) MS3Å, 2 (1 atm) PhC 3, 80 C 95% yield Trend, R. M.; Ramtohul, Y. K.; Ferreira, E. M.; Stoltz, B. M. Angew. Chem. Int. Ed. 2003, 42, 2892.
84 Stereochemistry of xidative Cyclizations Stoltz Group Studies (TFA) 2 (5 mol%) pyridine (20 mol%) Na 2 C 3 (2 equiv) MS3Å, 2 (1 atm) PhC 3, 80 C 95% yield C 2 Et NTs NBn 90% yield 88% yield 63% yield 82% yield 87% yield 93% yield 62% yield Trend, R. M.; Ramtohul, Y. K.; Ferreira, E. M.; Stoltz, B. M. Angew. Chem. Int. Ed. 2003, 42, 2892.
85 Stereochemistry of xidative Cyclizations Stoltz Group Studies E [ II ] E E [ II ] E E E anti oxypalladation C 2 Et C 2 Et E E [ II ] E E [] E E syn oxypalladation Trend, R. M.; Ramtohul, Y. K.; Stoltz, B. M. J. Am. Chem. Soc. 2005, 127,
86 Stereochemistry of xidative Cyclizations Stoltz Group Studies E [ II ] E E [ II ] E E E anti oxypalladation C 2 Et C 2 Et C 2 Et C 2 Et + C 2 Et C 2 Et E E [ II ] E E [] E E syn oxypalladation Trend, R. M.; Ramtohul, Y. K.; Stoltz, B. M. J. Am. Chem. Soc. 2005, 127,
87 Stereochemistry of xidative Cyclizations Stoltz Group Studies E E [ II ] anti oxypalladation E [ II ] E E E C 2 Et C 2 Et E E [ II ] syn oxypalladation E E [] E E Trend, R. M.; Ramtohul, Y. K.; Stoltz, B. M. J. Am. Chem. Soc. 2005, 127,
88 Stereochemistry of xidative Cyclizations Stoltz Group Studies E E [ II ] anti oxypalladation E [ II ] E E E C 2 Et C 2 Et C 2 Et C 2 Et E E [ II ] syn oxypalladation E E [] E E Trend, R. M.; Ramtohul, Y. K.; Stoltz, B. M. J. Am. Chem. Soc. 2005, 127,
89 Stereochemistry of xidative Cyclizations ayashi Group Studies (MeCN) 4 (BF 4 ) 2 (5 mol%) (S,S)-ip-boxax (/L* = 1/2) benzoquinone (4 equiv) Me, 40 C, 4 h A:B:C: = 16:46:29:9 A B syn oxypalladation C ayashi, T.; Yamasaki, K.; Mimura, M.; Uozumi, Y. J. Am. Chem. Soc. 2004, 126, 3036.
90 Stereochemistry of xidative Cyclizations ayashi Group Studies (MeCN) 4 (BF 4 ) 2 (5 mol%) (S,S)-ip-boxax (/L* = 1/2) benzoquinone (4 equiv) Me, 40 C, 4 h A:B:C: = 16:46:29:9 A B syn oxypalladation C 2 (MeCN) 2 (10 mol%) Na 2 C 3 (2 equiv) Li (2 equiv) benzoquinone (1 equiv) TF, 65 C, 24 h A:B:C: = 6:5:7:82 A B anti oxypalladation C ayashi, T.; Yamasaki, K.; Mimura, M.; Uozumi, Y. J. Am. Chem. Soc. 2004, 126, 3036.
91 Stereochemistry of xidative Cyclizations Stahl Group Studies anti aminopalladation L n Ts N Ts N Ts N Ts N NTs L n Ts N Ts N Ts N syn aminopalladation Ts N Liu, G.; Stahl, S. S. J. Am. Chem. Soc. 2007, 129, 6328.
92 Stereochemistry of xidative Cyclizations Stahl Group Studies anti aminopalladation L n Ts N Ts N Ts N Ts N NTs No additive: L n 2:1 ratio syn:anti aminopalladation products Ts N Ts N Ts N syn aminopalladation Ts N Liu, G.; Stahl, S. S. J. Am. Chem. Soc. 2007, 129, 6328.
93 Stereochemistry of xidative Cyclizations Stahl Group Studies anti aminopalladation L n Ts N Ts N Ts N Ts N NTs C 2 Additive: L n 1:2 ratio syn:anti aminopalladation products Ts N Ts N Ts N syn aminopalladation Ts N Liu, G.; Stahl, S. S. J. Am. Chem. Soc. 2007, 129, 6328.
94 Stereochemistry of xidative Cyclizations Stahl Group Studies anti aminopalladation L n Ts N Ts N Ts N Ts N NTs NaAc or Na 2 C 3 Additive: L n exclusively syn aminopalladation products Ts N Ts N Ts N syn aminopalladation Ts N Liu, G.; Stahl, S. S. J. Am. Chem. Soc. 2007, 129, 6328.
95 Conclusions Source and Ligands Additive Effects (co-oxidant, acid, base, salts) syn vs. anti heteropalladation or carbopalladation Solvent Effects ( 2, R, MS, etc.) lefin Sterics and Electronics Nucleophile Sterics and Electronics
96 The Wacker xidation ne-stage Process purge C 2 4 C 2 4, 2 Reactor 2, Cu 2, C 2 4, C 3 C Separation Equipment! Required brick and rubber-lined reactors and titanium pipes.! Requires an 2 plant.! perates at C, 3 atm, and p between 0.8 and 3.0.! Yields >95% acetaldehyde. C 3 C Wiseman, P. Introduction to Industrial rganic Chemistry; 2nd Ed.; Applied Science Publishers: London, 1979; pp
97 The Wacker xidation Two-Stage Process! Required brick and rubber-lined reactors and titanium pipes.! Uses ambient air as 2 source and impure mixtures of ethylene. C 3 C! perates at C, 10 atm.! Yields >95% acetaldehyde. C 2 4 2, Cu 2, xidation Reactor 2, (Cu) 2, + C 3 C Separation Equipment 2, (Cu) 2, N 2 Regeneration Reactor air Wiseman, P. Introduction to Industrial rganic Chemistry; 2nd Ed.; Applied Science Publishers: London, 1979; pp
98
The Mechanistic Studies of the Wacker Oxidation. Tyler W. Wilson SED Group Meeting
The Mechanistic Studies of the Wacker xidation Tyler W. Wilson SE Group Meeting 11.27.2007 Introduction xidation of ethene by (II) chloride solutions (Phillips, 1894) -First used as a test for alkenes
The Catalytic Chemistry of Palladium (II)
Chapter 4 The Catalytic Chemistry of Palladium (II) Main on-organometallic (II) Sources [ 2 ] n = n insoluble 2 MeC 2 Li 2 PPh 3 2 (MeC) 2 2 (PPh 3 ) 2 Li 2 4 soluble 2 Ag 2 AgBF4 2 MeC (MeC) 4 (BF 4 )
Aza-Wacker-Type Cyclization. Group Meeting Tuesday, April 19, 2011 William Kuester
Aza-Wacker-Type Cyclization Group Meeting Tuesday, April 19, 2011 William Kuester N-heterocylization Reductive Amination Hydroamination Oxidative Cyclization Chemler, S.R. Org. Biomol. Chem. 2009, 7, 3009-3019.
Studies on Heck and Suzuki Reactions Catalyzed by Palladium(0) and Wacker- Type Oxidative Cyclization Catalyzed by Palladium(II)
Studies on eck and Suzuki Reactions Catalyzed by Palladium(0) and Wacker- Type xidative Cyclization Catalyzed by Palladium() Zuhui Zhang enmark Group Meeting 10/21/2008 1 Part ne: Palladium(0)-Catalyzed
Additions to Metal-Alkene and -Alkyne Complexes
Additions to tal-alkene and -Alkyne Complexes ecal that alkenes, alkynes and other π-systems can be excellent ligands for transition metals. As a consequence of this binding, the nature of the π-system
O + k 2. H(D) Ar. MeO H(D) rate-determining. step?
ame: CEM 633: Advanced rganic Chem: ysical Problem Set 6 (Due Thurs, 12/8/16) Please do not look up references until after you turn in the problem set unless otherwise noted. For the following problems,
1.1 An Introduction to Oxidative Kinetic Resolution. Enantiopure secondary alcohols are invaluable in organic synthesis as they are
Chapter 1 Introduction 1 CAPTER 1 1.1 An Introduction to xidative Kinetic Resolution 1.1.1 Introduction Enantiopure secondary alcohols are invaluable in organic synthesis as they are found in natural products
Metal Catalyzed Outer Sphere Alkylations of Unactivated Olefins and Alkynes
Metal Catalyzed uter Sphere Alkylations of Unactivated lefins and Alkynes Stephen Goble rganic Super-Group Meeting Literature Presentation ctober 6, 2004 1 utline I. Background Introduction to Carbometallation
Direct Oxidative Heck Cyclizations: Intramolecular Fujiwara-Moritani Arylations for the Synthesis of Functionalized Benzofurans and Dihydrobenzofurans
Direct xidative eck Cyclizations: Intramolecular Fujiwara-Moritani Arylations for the Synthesis of Functionalized Benzofurans and Dihydrobenzofurans by Zhang,.; Ferreira, E. M.; Stoltz, B. M. Angewandte
CO 2 and CO activation
2 and activation Most organic chemicals are currently made commercially from ethylene, a product of oil refining. It is possible that in the next several decades we may have to shift toward other carbon
Suggested solutions for Chapter 40
s for Chapter 40 40 PBLEM 1 Suggest mechanisms for these reactions, explaining the role of palladium in the first step. Ac Et Et BS () 4 2 1. 2. K 2 C 3 evision of enol ethers and bromination, the Wittig
Lecture 6: Transition-Metal Catalysed C-C Bond Formation
Lecture 6: Transition-Metal Catalysed C-C Bond Formation (a) Asymmetric allylic substitution 1 u - d u (b) Asymmetric eck reaction 2 3 Ar- d (0) Ar 2 3 (c) Asymmetric olefin metathesis alladium π-allyl
CO 2 and CO activation
2 and activation Most organic chemicals are currently made commercially from ethylene, a product of oil refining. Itispossiblethatinthenextseveraldecadeswemayhavetoshifttowardothercarbonsources for these
H Organometallic Catalysis in Industry
H Organometallic Catalysis in Industry Some terminology: Catalytic cycles: a circular path meant to show productive reactions, in order, that lead from the catalytically active species and its reaction
CHEM 251 (4 credits): Description
CHEM 251 (4 credits): Intermediate Reactions of Nucleophiles and Electrophiles (Reactivity 2) Description: An understanding of chemical reactivity, initiated in Reactivity 1, is further developed based
Anti-Markovnikov Olefin Functionalization
Anti-Markovnikov Olefin Functionalization ~Prof. Robert H. Grubbs Work~ 4 th Literature Seminar July 5, 2014 Soichi Ito (D1) Contents 1. Introduction Flow of Prof. Grubbs Research Markovnikov s Rule Wacker
CH 3 TMG, DMF N H 3 CO 2 S. (PPh 3 ) 2 Pd 0
1. (a) rovide a reasonable mechanism for the following transformation. I S 2 C 3 C 3 ( 3 ) 2 2, CuI C 3 TMG, DMF 3 C 2 S TMG = Me 2 Me 2 ICu ( 3 ) 2 0 I S 2 C 3 S 2 C 3 Cu I 3 3 3 C 2 S I 3 3 3 C 2 S 3
CHEM Lecture 7
CEM 494 Special Topics in Chemistry Illinois at Chicago CEM 494 - Lecture 7 Prof. Duncan Wardrop ctober 22, 2012 CEM 494 Special Topics in Chemistry Illinois at Chicago Preparation of Alkenes Elimination
Shi Asymmetric Epoxidation
Shi Asymmetric Epoxidation Chiral dioxirane strategy: R 3 + 1 xone, ph 10.5, K 2 C 3, H 2, C R 3 formed in situ catalyst (10-20 mol%) is prepared from D-fructose, and its enantiomer from L-sorbose oxone,
14-1 Reactions Involving Gain or Loss of Ligands Reactions Involving Modification of Ligands
Organometallic Reaction and Catalysis 14-1 Reactions Involving Gain or Loss of Ligands 14-2 Reactions Involving Modification of Ligands 14-3 Organometallic Catalysts 14-4 Heterogeneous Catalysts Inorganic
Chiral Brønsted Acid Catalysis
Chiral Brønsted Acid Catalysis Aryl Aryl Aryl Aryl S CF 3 2 P Fe CF 3 CF 3 2 Jack Liu ov. 16, 2004 CF 3 Introduction Chiral Brønsted acid catalysis in nature: enzymes and peptides Chiral Brønsted acid
Nucleophilic attack on ligand
Nucleophilic attack on ligand Nucleophile "substitutes" metal hapticity usually decreases xidation state mostly unchanged Competition: nucleophilic attack on metal usually leads to ligand substitution
Lecture 11 Organic Chemistry 1
EM 232 rganic hemistry I at hicago Lecture 11 rganic hemistry 1 Professor Duncan Wardrop February 16, 2010 1 Self Test Question What is the product(s) of the following reaction? 3 K( 3 ) 3 A 3 ( 3 ) 3
Ligand Substitution Reactivity of Coordinated Ligands
Reactivity of Coordinated Ligands 2 C 2 H 4 (0) + H + + + 2 2 e (Cu 2 Cu) H CH 3 CH H "βh elim" ins βh elim H Peter H.M. Budzelaar Why care about substitution? Basic premise about metalcatalyzed reactions:
Insertion Reactions. 1) 1,1 insertion in which the metal and the X ligand end up bound to the same (1,1) atom
Insertion Reactions xidative addition and substitution allow us to assemble 1e and 2e ligands on the metal, respectively. With insertion, and its reverse reaction, elimination, we can now combine and transform
Molybdenum-Catalyzed Asymmetric Allylic Alkylation
Molybdenum-Catalyzed Asymmetric Allylic Alkylation X MoL n u u * Tommy Bui 9/14/04 Asymmetric Allylic Alkylation from a Synthetic Viewpoint X X M u u * and/or u form a C-C bond with the creation of a new
CHEM 153 PRACTICE TEST #1 ANSWER KEY
CEM 153 PACTICE TEST #1 ASWE KEY Provide a mechanism for the following transformation, indicating the electron count and oxidation state of each organometallic intermediate: u 3 (C) 12 (5 mol%) TF, 135
Non-Linear Effects in Asymmetric Catalysis: A Useful Tool in Understanding Reaction Mechanisms. Group Meeting Aaron Bailey 12 May 2009
Non-Linear Effects in Asymmetric Catalysis: A Useful Tool in Understanding Reaction chanisms Group eting Aaron Bailey 12 May 2009 What is a Non-Linear Effect? In asymmetric catalysis, the ee (er) of the
VI. Metal alkyls from oxidative addition / insertion
V. Metal alkyls from oxidative addition / insertion A. Carbonylation - C insertion very facile, metal acyls easily cleaved, all substrates which undergo oxidative addition can in principle be carbonylated.
Organometallic Chemistry and Homogeneous Catalysis
rganometallic hemistry and omogeneous atalysis Dr. Alexey Zazybin Lecture N8 Kashiwa ampus, December 11, 2009 Types of reactions in the coordination sphere of T 3. Reductive elimination X-L n -Y L n +
The aza-baylis-hillman Reaction: Mechanism, Asymmetric Catalysis, & Abnormal Adducts. Larry Wolf SED Group Meeting
The aza-baylis-hillman Reaction: Mechanism, Asymmetric Catalysis, & Abnormal Adducts Larry Wolf SED Group Meeting 04-10-07 Outline Brief historical account and Utility Mechanism Different methods for asymmetric
Chem 253 Problem Set 7 Due: Friday, December 3, 2004
Chem 253 roblem Set 7 ue: Friday, ecember 3, 2004 Name TF. Starting with the provided starting material, provide a concise synthesis of. You may use any other reagents for your synthesis. It can be assumed
Advanced Organic Chemistry
D. A. Evans, G. Lalic Question of the day: Chemistry 530A TBS Me 2 C Me toluene, 130 C 70% TBS C 2 Me H H Advanced rganic Chemistry Me Lecture 16 Cycloaddition Reactions Diels _ Alder Reaction Photochemical
Chap 11. Carbonyl Alpha-Substitution Reactions and Condensation Reactions
Chap 11. Carbonyl Alpha-Substitution eactions and Condensation eactions Four fundamental reactions of carbonyl compounds 1) Nucleophilic addition (aldehydes and ketones) ) Nucleophilic acyl substitution
Functionalization of terminal olefins via H migratory insertion /reductive elimination sequence Hydrogenation
M.C. White, Chem 153 verview -282- Week of ovember 11, 2002 Functionalization of terminal olefins via migratory insertion /reductive elimination sequence ydrogenation ML n E ydrosilylation Si 3 Si 3 ML
Course 201N 1 st Semester Inorganic Chemistry Instructor: Jitendra K. Bera
andout-10 ourse 201N 1 st Semester 2006-2007 Inorganic hemistry Instructor: Jitendra K. Bera ontents 3. rganometallic hemistry omogeneous atalysis lefin ydrogenation; ydroformylation; Monsanto Acetic acid
The aldol reaction with metal enolates proceeds by a chair-like, pericyclic process: favored. disfavored. favored. disfavored
The aldol reaction with metal enolates proceeds by a chair-like, pericyclic process: Z-enolates: M 2 M 2 syn 2 C 2 favored 2 M 2 anti disfavored E-enolates: M 2 2 C 3 C 3 C 2 favored 2 M M disfavored In
Nucleophilic Substitution and Elimination
Nucleophilic Substitution and Elimination Alkyl halides react with a nucleophile in one of two ways. Either they eliminate an X to form an alkene, or they undergo a substitution with the nucleophile, Nu,
REACTION AND SYNTHESIS REVIEW
REACTION AND SYNTHESIS REVIEW A STUDENT SHOULD BE ABLE TO PREDICT PRODUCTS, IDENTIFY REACTANTS, GIVE REACTION CONDITIONS, PROPOSE SYNTHESES, AND PROPOSE MECHANISMS (AS LISTED BELOW). REVIEW THE MECHANISM
Suggested solutions for Chapter 32
s for Chapter 32 32 PBLEM 1 Explain how the stereo- and regio- chemistry of these reactions are controlled. Why is the epoxidation only moderately diastereoselective, and why does the amine attack where
Mechanism Problem. 1. NaH allyl bromide, THF N H
Mechanism Problem 1. a allyl bromide, TF 2. 9-BB (1.2 equiv), TF, rt; ame (1.2 equiv); t-buli (2.4 equiv), TMEDA (2.4 equiv) 30 to rt; allyl bromide; 30% 2 2, aq. a, 0 C (58% yield) Mechanism Problem 9-BB
Highlights of Schmidt Reaction in the Last Ten Years
ighlights of Schmidt eaction in the Last Ten Years Dendrobates histrionicus Jack Liu ov. 18, 2003 Introduction Classical Schmidt reaction of aldehydes and carboxylic acids Classical Schmidt reaction of
Initials: 1. Chem 633: Advanced Organic Chemistry 2016 Final Exam
Initials: 1 ame: Chem 633: Advanced rganic Chemistry 2016 Final Exam This exam is closed note, closed book. Please answer the following questions clearly and concisely. In general, use pictures and less
(Neither an oxidation or reduction: Addition or loss of H +, H 2 O, HX).
eactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations the majority of which are either oxidation or reduction type reactions. xidation is a
Wilkinson s other (ruthenium) catalyst
Wilkinson s other (ruthenium) catalyst Cl 3 ; 2 h 3, reflux 3h h 3 Cl h 3 h Cl 3 Good catalyst especially for 2 1-alkenes 2, base toluene Cl h 3 h 3 h 3 Et 3 Cl h 3 Cl h 3 h 3 R h 3 h 3 Cl h 3 R RC 2 C
Hydroboration. Carreira: Chapter 7
ydroboration Carreira: Chapter 7 ydroboration of alkenes/alkynes is one of the most versatile reactions available. Most commonly, the resulting alkyl borane intermediates are not isolated, but are used
CuI CuI eage lic R tal ome rgan gbr ommon
Common rganometallic eagents Li Et 2 Li Mg Et 2 Li alkyllithium rignard Mg Mg Li Zn TF ZnCl 2 TF dialkylzinc Zn 2 2 Zn Li CuI TF ganocuprate CuI 2 2 CuI common electrophile pairings ' Cl ' '' ' ' ' ' '
Suggested solutions for Chapter 19
s for Chapter 19 19 PRBLEM 1 Predict the orientation of addition to these alkenes. Simple examples of addition with regioselectivity. The first and last alkenes have different numbers of substituents at
O H HO H. !-D-galactopyranose
ame Key W06-Exam o. Page I. ( points) A disaccharide is cleaved by a β-glycosidase, an enzyme that specifically hydrolyzes a β- glycosidic linkage. When the disaccharide is treated with excess dimethyl
Elementary Organometallic Reactions
Elementary eactions CE 966 (Tunge) Elementary rganometallic eactions All mechanisms are simply a combination of elementary reactions. 1) Coordination -- issociation 2) xidative Addition -- eductive Elimination
Stereodivergent Catalysis. Aragorn Laverny SED Group Meeting July
Stereodivergent Catalysis Aragorn Laverny SED Group Meeting July 31 2018 1 Stereodivergent Catalysis In the context of asymmetric synthesis, a stereodivergent process is one that allows access to any given
Highly Efficient, Convergent, and Enantioselective Synthesis of Phthioceranic Acid
Highly Efficient, Convergent, and Enantioselective Synthesis of Phthioceranic Acid Shiqing Xu, Akimichi Oda, Thomas Bobinski, Haijun Li, Yohei Matsueda, and Ei-ichi Negishi Angew. Chem. Int. Ed. 2015,
Only five of the molecules below may be prepared as the sole product of allylic halogenation of the respective alkene. Circle those five.
Chem 232 D. J. Wardrop wardropd@uic.edu Problem Set 6 Answers Question 1. nly five of the molecules below may be prepared as the sole product of allylic halogenation of the respective alkene. Circle those
CHAPTER 7. Further Reactions of Haloalkanes: Unimolecular Substitution and Pathways of Elimination
CHAPTER 7 Further Reactions of Haloalkanes: Unimolecular Substitution and Pathways of Elimination 7-1 Solvolysis of Tertiary and Secondary Haloalkanes The rate of S N 2 reactions decrease dramatically
Direct, Catalytic Hydroaminoalkylation of Unactivated Olefins with N-Alkyl Arylamines
Current Literature - May 12, 2007 Direct, Catalytic ydroaminoalkylation of Unactivated lefins with -Alkyl ylamines ' '' Ta[ 2 ] 5 (4-8 mol%), 160-165 o C 24-67h 66-95% ' '' S. B. erzon and J. F. artwig,
Stereoselective reactions of the carbonyl group
1 Stereoselective reactions of the carbonyl group We have seen many examples of substrate control in nucleophilic addition to the carbonyl group (Felkin-Ahn & chelation control) If molecule does not contain
PAPER No. : Paper-9, Organic Chemistry-III (Reaction Mechanism-2) MODULE No. : Module-10, Hydroboration Reaction CHEMISTRY
Subject Chemistry Paper No and Title Module No and Title Module Tag Paper-9, Organic Chemistry-III (Reaction Mechanism-2) Module-10, Hydroboration Reaction CHE_P9_M10 TABLE OF CONTENTS 1. Learning Outcomes
Organic Chemistry I (Chem340), Spring Final Exam
rganic Chemistry I (Chem340), pring 2005 Final Exam This is a closed-book exam. No aid is to be given to or received from another person. Model set and calculator may be used, but cannot be shared. Please
Titanacyclopropanes as versatile intermediates for carbon carbon bond formation in reactions with unsaturated compounds*
Pure Appl. Chem., Vol. 72, No. 9, pp. 1715 1719, 2000. 2000 IUPAC Titanacyclopropanes as versatile intermediates for carbon carbon bond formation in reactions with unsaturated compounds* O. G. Kulinkovich
Organometallics Study Meeting Part 4. Reactions of Organometallic Complexes
rganometallics Study eeting art 4. eactions of rganometallic Complexes 1. asics 2011/4/28 oshino(d1).10 1-1. igand Exchange Dissosiative echanism ' n n-1 ' n-1 Fe(C) 5 (18e):hoto-promoteddissociationofigand
Recent advances in transition metal-catalyzed or -mediated cyclization of 2,3-allenoic acids: New methodologies for the synthesis of butenolides*
Pure Appl. Chem., Vol. 76, No. 3, pp. 651 656, 2004. 2004 IUPAC Recent advances in transition metal-catalyzed or -mediated cyclization of 2,3-allenoic acids: New methodologies for the synthesis of butenolides*
Regioselective Reductive Cross-Coupling Reaction
Lit. Seminar. 2010. 6.16 Shinsuke Mouri (D3) Regioselective Reductive Cross-Coupling Reaction Glenn C. Micalizio obtained a Ph.D. at the University of Michigan in 2001 under the supervision of Professor
Asymmetric Catalysis by Lewis Acids and Amines
Asymmetric Catalysis by Lewis Acids and Amines Asymmetric Lewis acid catalysis - Chiral (bisooxazoline) copper (II) complexes - Monodentate Lewis acids: the formyl -bond Amine catalysed reactions Asymmetric
TMSCl imidazole DMF. Ph Ph OTMS. Michael reaction. Michael reaction Ph R 3. epoxidation O R
eaction using diarylprolinol silyl ether derivatives as catalyst 1) C Et K C 3, ) MgBr, TF TMS hexane, 0 o C TBS p- C 6 4, T C Et 85%, 99% ee Angew. Chem., nt. Ed., 44, 41 (005). rg. Synth., 017, 94, 5.
Elimination Reactions Heating an alkyl halide with a strong base causes elimination of a. molecule of HX
Elimination eactions eating an alkyl halide with a strong base causes elimination of a molecule of X 1. Potassium hydroxide dissolved in ethanol and the sodium salts of alcohols (such as sodium ethoxide)
Chapter 11: Nucleophilic Substitution and Elimination Walden Inversion
hapter 11: Nucleophilic Substitution and Elimination Walden Inversion (S)-(-) Malic acid [a] D = -2.3 Ag 2, 2 Pl 5 l Ag 2, 2 ()-2-hlorosuccinic acid l (-)-2-hlorosuccinic acid Pl 5 ()-() Malic acid [a]
1. Radical Substitution on Alkanes. 2. Radical Substitution with Alkenes. 3. Electrophilic Addition
1. Radical Substitution on Alkanes Only Cl and Br are useful at the laboratory level. Alkane reactivity: tertiary > secondary > primary > methyl Numbers below products give their relative yield. Relative
Chem 251 Fall Learning Objectives
Learning Objectives Chapter 8 (last semester) 1. Write an electron-pushing mechanism for an SN2 reaction between an alkyl halide and a nucleophile. 2. Describe the rate law and relative rate of reaction
Radical Reactions. Radical Stability!!! bond dissociation energies X Y X + Y. bond BDE (kcal/mol) bond BDE (kcal/mol) CH 3 CH 3 CH 2 95 O H R 2 C H
adical eactions adical Stability!!! bond dissociation energies X Y X Y bond BDE (kcal/mol) bond BDE (kcal/mol) C 3 104 108 C 3 C 2 98 110 95 2 C 102 (-) 93 (C-) 92 C 3 C 3 36 89 85 C 3 C 3 80 adical eactions
Some Hartwig Chemistry Experimental Approaches and Detailed Mechanistic Analysis
Some artwig Chemistry Experimental Approaches and Detailed chanistic Analysis b. 1964 1986 A.B. Princeton U, Maitland Jones 1990.D. UC Berkeley, obert Bergman and ichard Anderson 1990-92 Post-doc, MIT,
Lecture 20 Organic Chemistry 1
CEM 232 rganic Chemistry I at Chicago Lecture 20 rganic Chemistry 1 Professor Duncan Wardrop March 18, 2010 1 Self-Test Question Capnellene (4) is a marine natural product that was isolated from coral
Ethers. Synthesis of Ethers. Chemical Properties of Ethers
Page 1 of 6 like alcohols are organic derivatives of water, but lack the labile -OH group. As a result, ethers, except for epoxides, are usually not very reactive and are often used as solvents for organic
acetaldehyde (ethanal)
hem 263 Nov 2, 2010 Preparation of Ketones and Aldehydes from Alkenes zonolysis 1. 3 2. Zn acetone 1. 3 2. Zn acetone acetaldehyde (ethanal) Mechanism: 3 3 3 + - oncerted reaction 3 3 3 + ozonide (explosive)
(b) (CH 3 ) 2 CCH 2 CH 3 D 2 O. (e) A. CH 3 CCl OSO 2 CH 3 C 6 H 5 H 3 C
278 h a p t e r 7 Further Reactions of aloalkanes 3. arbocations are stabilized by hyperconjugation: Tertiary are the most stable, followed by secondary. Primary and methyl cations are too unstable to
Chem 263 March 28, 2006
Chem 263 March 28, 2006 Properties of Carboxylic Acids Since carboxylic acids are structurally related to both ketones and aldehydes, we would expect to see some similar structural properties. The carbonyl
Andrew Yeung CHEM636
Andrew Yeung CHEM636 Scope verview olyketones and their synthesis Timeline of development Catalyst selection alladium vs. nickel Ligands Mechanism Initiation & termination ropagation roperties Low T g
Chiral Catalyst II. Palladium Catalysed Allylic Displacement ( -allyl complexes) 1. L n Pd(0) 2. Nuc
Chiral Catalyst II ast lecture we looked at asymmetric catalysis for oxidation and reduction Many other organic transformations, this has led to much investigation Today we will look at some others...
Aldehydes and Ketones : Aldol Reactions
Aldehydes and Ketones : Aldol Reactions The Acidity of the a Hydrogens of Carbonyl Compounds: Enolate Anions Hydrogens on carbons a to carbonyls are unusually acidic The resulting anion is stabilized by
Basic Organic Chemistry Course code : CHEM (Pre-requisites : CHEM 11122)
Basic Organic Chemistry Course code : CHEM 12162 (Pre-requisites : CHEM 11122) Chapter 01 Mechanistic Aspects of S N2,S N1, E 2 & E 1 Reactions Dr. Dinesh R. Pandithavidana Office: B1 222/3 Phone: (+94)777-745-720
deactivation or decomposition is therefore quantified using the turnover number.
A catalyst may be defined by two important criteria related to its stability and efficiency. Name both of these criteria and describe how they are defined with respect to stability or efficiency. A catalyst
CHEMISTRY Topic #4: Electrophilic Addition Reactions of Alkenes and Alkynes Fall 2018 Dr. Susan Findlay
EMISTRY 2600 Topic #4: Electrophilic Addition Reactions of Alkenes and Alkynes Fall 2018 Dr. Susan Findlay rganic Reactions (EM 2500 Review) Most reactions in organic chemistry fall into one (or more)
Lecture Notes Chem 51C S. King. Chapter 20 Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation & Reduction
Lecture Notes Chem 51C S. King Chapter 20 Introduction to Carbonyl Chemistry; rganometallic Reagents; xidation & Reduction I. The Reactivity of Carbonyl Compounds The carbonyl group is an extremely important
Química Orgânica I. Ciências Farmacêuticas Bioquímica Química AFB QO I 2007/08 1
Química rgânica I Ciências Farmacêuticas Bioquímica Química AFB Q I 2007/08 1 alcohols Adaptado de rganic Chemistry, 6th Edition; Wade rganic Chemistry, 6 th Edition; McMurry AFB Q I 2007/08 2 Typical
Preparation of alkenes
Lecture 11 אלקנים הכנה ותגובות של אלקנים: הידרוגנציה, סיפוח הידרוהלוגנים )כלל מארקובניקוב(, סיפוח הלוגנים והסטראוכימיה של תוצרי הסיפוח, הידרובורציה, אפוקסידציה, אוזונוליזה. 1 Preparation of alkenes 1.
Chiral Catalysis. Chiral Catalyst. Substrate. Chiral Catalyst
Chiral Catalysis Chiral (stoichiometric) reagents are a very important class of compound but... eed a stoichiometric quantity of the chiral component Unless it is cheap or recoverable this is not very
Transition Metal Chemistry
Transition Metal Chemistry 2 2011.12.2 Ⅰ Fundamental Organometallic Reactions Following four reactions are important formal reaction patterns in organotransition metal complexes, which would conveniently
Total Syntheses of Minfiensine
Total Syntheses of Minfiensine Douany, A. B.; umphreys, P. G.; verman, L. E.*; Wrobelski, A. D., J. Am. Chem. Soc. 2008, ASAP. D: 10.1021/ja800163v Shen, L.; Zhang, M.; Wu, Y.; Qin, Y.*, Angew. Chem. nt.
sp 3 C-H Alkylation with Olefins Yan Xu Dec. 3, 2014
sp 3 C-H Alkylation with Olefins, Yan Xu Dec. 3, 2014 1) sp 3 C-H Alkylation via Directed C-H activation 2) Hydroaminoalkylation (still via C-H activation) 3) Hydrohydroxyalkylation (via radical chemistry)
Massachusetts Institute of Technology Organic Chemistry Problem Set 1. Functional Group Transformations Study Guide
Massachusetts Institute of Technology rganic Chemistry 5.511 Problem Set 1 September, 2007 Prof. Rick L. Danheiser Functional Group Transformations Study Guide The purpose of this three-part study guide
A Tandem Semipinacol Rearrangement/Alkylation of a-epoxy Alcohols: An Efficient and Stereoselective Approach to Multifunctional 1,3-Diols
A Tandem Semipinacol Rearrangement/Alkylation of a-epoxy Alcohols: An Efficient and Stereoselective Approach to Multifunctional 1,3-Diols B() 2 H H B() 2 H H Hu, X.-D.; Fan, C.-A.; Zhang, F.-M.; Tu, Y.
1. Addition of HBr to alkenes
eactions of Alkenes I eading: Wade chapter 8, sections 8-1- 8-8 tudy Problems: 8-47, 8-48, 8-55, 8-66, 8-67, 8-70 Key Concepts and kills: Predict the products of additions to alkenes, including regiochemistry
Epoxidation with Peroxy Acids
Epoxidation with Peroxy Acids RC 3 R C more reactive more likely Freccero, M.; Gandolfi, R.; Sarzi-Amadè, M.; Rastelli, A. J. rg. Chem. 2000, 65, 2030. Singleton, D. A.; Merrigan, S. R.; Liu, J.; ouk,
Chapter 8: Addition Reactions
Chapter 8: Addition Reactions Addition Reactions to Alkenes (Section 8.1) Markovnikov s Rule (Section 8.2) Stereochemistry of Ionic Addition to Alkenes (Section 8.3) 2 S 4 Additions to Alkenes (Section
Chapter 8: Chemistry of Alkynes (C n H 2n-2 )
hapter 8: hemistry of Alkynes ( n 2n-2 ) Bonding & hybridization Both are sp-hybridized Bond angles = 180 o 1 σ + 2 π bonds Linear around lassification R R R' σ bond energy: 88 kcal/mol π bond energy:
Chapter 5B. Functional Group Transformations: The Chemistry. Related Reactions
Chapter 5B Functional Group Transformations: The Chemistry of fcarbon-carbon C b π-bonds B d and Related Reactions Oxymercuation-Demercuration Markovnikov hydration of a double bond 1 Mechanism Comparision
Part C- section 1 p-bonds as nucleophiles
Part C- section 1 p-bonds as nucleophiles Chemistry of Alkenes (Ch 8, 9, 10) - the double bond prevents free rotation - isomerism cis and trans - nomenclature E and Z (3 or 4 different substituents around
Chapter 7: Alkene reactions conversion to new functional groups
hapter 7: Alkene reactions conversion to new functional groups Preparation of alkenes: two common elimination reactions 1. Dehydration of alcohols Dehydration is a common biochemical reaction in carbohydrate
Olefin Metathesis ROMP. L n Ru= ROMP n RCM. dilute
lefin Metathesis MP: ing-opening metathesis polymerization Thermodynamically favored for 3,4, 8, larger ring systems Bridging groups (bicyclic olefins) make ΔG polymerization more favorable as a result
But in organic terms: Oxidation: loss of H 2 ; addition of O or O 2 ; addition of X 2 (halogens).
Reactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations the majority of which are either oxidation or reduction type reactions. Normally: Oxidation
PAPER No. : 5; Organic Chemistry-II MODULE No. : 13; Mixed S N 1 and S N 2 Reactions
Subject Chemistry Paper No and Title Module No and Title Module Tag 5; Organic Chemistry-II 13; Mixed S N 1 and S N 2 Reactions CHE_P5_M13 TABLE OF CONTENTS 1. Learning Outcomes 2. Introduction 3. Nature