Applications of Non-Commercially Available Metathesis Catalysts
|
|
|
- Priscilla Mitchell
- 5 years ago
- Views:
Transcription
1 Applications of on-commercially Available tathesis Catalysts or A Simple Guide to ptimizing tathesis eactions Bz + Ac Ac 3 mol% catalyst, reflux, 6h Bz Ac MacMillan Group eting January 16, % 87%
2 An Alternate eality Consider a situation wherein only four phosphine ligands are commercially available P 3, P( t Bu) 3, dppf and BIAP would accomplish many, if not most, coupling reactions Certain total syntheses would be conspicuously absent TBS 2 C Boc Pd 2 (dba) 3, (o-tolyl) 3 P //1 a 2 C 3 TBS 2 C Boc Cbz Br MEM 88% Boger, D.. et al. J. Am. Chem. Soc. 1999, 121, 3226.
3 An Alternate eality Bn Bn Ms Ms Ac Boc I Pd 2 (dba) 3, (o-tolyl) 3 P TEA, C, reflux Ac 83% Boc Fukuyama, T. et al. J. Am. Chem. Soc. 2002, 124, I Tf Bn Ts Bn Ts Pd 2 (dba) 3, (2-furyl) 3 P CuI, MP, rt Pd(Ac) 2, ()-Tol-BIAP PMP, C, 80 C I Tf Bn Ts Ts Bn 71% 62%, 90% ee verman,. E. et al. J. Am. Chem. Soc. 2002, 124, 9008.
4 osphine vs. Catalyst Choice early, the commercial availability of a variety of phosphines is key Few research groups use 'homemade' phosphine ligands Are we justified in also using only commercially available metathesis catalysts? PSPIE IGADS Widely commercially available Difficult to synthesize Few guiding mechanistic principles METATESIS CATAYSTS Few commercially available ften simple to synthesize Based strongly on mechanism
5 osphine vs. Catalyst Choice early, the commercial availability of a variety of phosphines is key Few research groups use 'homemade' phosphine ligands Are we justified in also using only commercially available metathesis catalysts? PSPIE IGADS Widely commercially available Difficult to synthesize Few guiding mechanistic principles METATESIS CATAYSTS Few commercially available ften simple to synthesize Based strongly on mechanism The key to time and fiscal efficiency is selection of the proper catalyst
6 Selection of a tathesis Catalyst First, one should ensure that the substrate has been optimized for commercially available catalysts After optimization, a catalyst to be synthesized should be rationally determined Both processes require an intimate working knowledge of the mechanism of olefin metathesis P 3 k 1 P 3 + P 3 k 2 + olefin olefin 1 k 1 k 2 k 2 k 2 k 3 k 3 1 k 3 k 3 Sanford, M. S.; ove, J. A.; Grubbs,.. J. Am. Chem. Soc. 2001, 123, 6543.
7 bservations on osphine Dissociation Surprisingly, 2 nd generation catalyst ( = 2 IMES) phosphine dissocation is 100 times less favored thylidine species ( = ) for either generation catalyst decompose competitively For all systems investigated, initiation in dichloromethane is 30% faster than in toluene P 3 k 1 P 3 + P 3 k 2 + olefin olefin 1 k 1 k 2 k 2 k 2 k 3 k 3 1 k 3 k 3 Sanford, M. S.; ove, J. A.; Grubbs,.. J. Am. Chem. Soc. 2001, 123, 6543.
8 bservations on lefin Binding 2 nd generation catalyst ( = 2 IMES) k 1 /k 2 is times lower (in favor of olefin binding) Somewhat surprisingly, is fairly independent of phosphine nature ( vs. P 3 = factor of 2) For comparison, relative rates of phosphine dissociation for P 3 / differ by 70-fold P 3 k 1 P 3 + P 3 k 2 + olefin olefin 1 k 1 k 2 k 2 k 2 k 3 k 3 1 k 3 k 3 Sanford, M. S.; ove, J. A.; Grubbs,.. J. Am. Chem. Soc. 2001, 123, 6543.
9 bservations on thenacyclobutane Use of Piers' catalysts at low ( 60 or 78 C) temperature allow observation of ruthenacyclobutane When ethylene is not removed from solution, unsubstituted cyclobutane is dominant species Unsubstituted metallacyclobutane is known to decompose to hydride containing species P 3 k 1 P 3 + P 3 k 2 + olefin olefin 1 k 1 k 2 k 2 k 2 k 3 k 3 1 k 3 k 3 van der Eide, E. F.; omero, P. E.; Piers, W. E. J. Am. Chem. Soc. submitted van ensburg, W. J. et al. J. Am. Chem. Soc. 2004, 126,
10 bservations on thenacyclobutane Use of Piers' catalysts at low ( 60 or 78 C) temperature allow observation of ruthenacyclobutane When ethylene is not removed from solution, unsubstituted cyclobutane is dominant species Unsubstituted metallacyclobutane is known to decompose to hydride containing species MAJ β-hydride elim. P 3 B(C 6 F 5 ) 3 2 C C 2 CD 2 2, 60 C 2 C C 2 C 2 C 2 MI van der Eide, E. F.; omero, P. E.; Piers, W. E. J. Am. Chem. Soc. submitted van ensburg, W. J. et al. J. Am. Chem. Soc. 2004, 126,
11 Stage 1: ptimization of eaction Conditions Combination of two terminal olefins and phosphine bearing catalyst may be problematic styrene C 2 C 2 P 3 + P 3 SW reentry into catalytic cycle styrene + P 3 P 3 P 3 APID reentry into catalytic cycle If both terminal olefins cannot be avoided due to substrate synthesis, choose ovyeda-grubbs
12 Stage 1: ptimization of eaction Conditions Substrate templating may offer a solution for cyclization of heteroatom rich macrocycles C M, >95% Grubbs' Gen. 1 (5 mol%) C 2 2 /TF 0.02M 39%, 6:4 trans:cis with i 4 : >95%, 100% cis m i 4, C 2 2 /TF 0.02M, >95% Marsella, M. J.; Maynard,. D.; Grubbs,.. Angew. Chem. Int. Ed. 1997, 36, Cyclodepoymerization is an especially important observation in these systems
13 Stage 1: ptimization of eaction Conditions ligomers have been detailed as common intermediates in CM Most efficient macrocyclization strategy may involve polymerization at high concentration followed by dilution and macrocycle formation 8 4 Grubbs' Gen. 2 (5 mol%) thod A or B thod A: 0.005M, 9h, 99% conv. thod B: 0.1M, then dilute to 0.005M, 1h total, 99% conv. 4 8 n Conrad, J. C. et al. J. Am. Chem. Soc. 2007, 129, 1024.
14 Stage 2: Selection of a Catalyst Even perfect substrate/reaction condition optimization may not solve every metathesis problem A number of easily synthesized catalysts have been recently reported, based on one of three improvements: rapid initiation, lessened steric demand or improved catalyst lifetime. ne must identify which of these factors will yield the greatest influence on reaction outcome P 3 k 1 P 3 + P 3 k 2 + olefin olefin 1 k 1 k 2 k 2 k 2 k 3 k 3 1 k 3 k 3 Sanford, M. S.; ove, J. A.; Grubbs,.. J. Am. Chem. Soc. 2001, 123, 6543.
15 Catalysts Based on apid Initiation The groups of Grubbs, Piers, Grela and Blechert have introduced rapidly initiating catalysts Better intitation results in a higher effective concentration of catalyst in solution P 3 k 1 P 3 + P 3 k 2 + olefin olefin 1 k 1 k 2 k 2 k 2 k 3 k 3 1 k 3 k 3 ove, J. A.; Morgan, J. P.; Trnka, T. M.; Grubbs,.. Angew. Chem. Int. Ed. 2002, 41, Grela, K.; arutyunyan, S.; Michrowska, A. Angew. Chem. Int. Ed. 2002, 41, Wakamatsu,.; Blechert, S. Angew. Chem. Int. Ed. 2002, 41, omero, P. E.; Piers, W. E.; McDonald,. Angew. Chem. Int. Ed. 2004, 43, 6161.
16 Grubbs' Third Generation ove, J. A.; Morgan, J. P.; Trnka, T. M.; Grubbs,.. Angew. Chem. Int. Ed. 2002, 41, Br Br eplacement of phosphine with two 3-bromopyridine ligands yields new precatalyst excess 3-BrC 5 4 Br Ease of synthesis = Exceptional Br
17 Grubbs' Third Generation ove, J. A.; Morgan, J. P.; Trnka, T. M.; Grubbs,.. Angew. Chem. Int. Ed. 2002, 41, Br Br eplacement of phosphine with two 3-bromopyridine ligands yields new precatalyst excess 3-BrC 5 4 Br Ease of synthesis = Exceptional Br Br + Br + Br Br Br Br Br While the precatalyst is coordinatively saturated, dissociation is rapid
18 Grela's itro-aryl Catalyst Grela, K.; arutyunyan, S.; Michrowska, A. Angew. Chem. Int. Ed. 2002, 41, Electronic deactivation of isopropoxy-donor is key design feature 2 steps - 49% styrene Ease of synthesis = Very Good 2 2 2
19 Grela's itro-aryl Catalyst Grela, K.; arutyunyan, S.; Michrowska, A. Angew. Chem. Int. Ed. 2002, 41, Electronic deactivation of isopropoxy-donor is key design feature 2 steps - 49% styrene Ease of synthesis = Very Good initial metathesis event 2 itro group renders the isopropoxy donor less ewis basic, thus more labile
20 Blechert's Biphenyl Catalyst Wakamatsu,.; Blechert, S. Angew. Chem. Int. Ed. 2002, 41, Steric interation between ortho substituents disfavors chelation 3 steps - 51% () styrene Ease of synthesis = Very Good
21 Blechert's Biphenyl Catalyst Wakamatsu,.; Blechert, S. Angew. Chem. Int. Ed. 2002, 41, Steric interation between ortho substituents disfavors chelation 3 steps - 51% () styrene Ease of synthesis = Very Good initial metathesis event Steric interaction in planar chelate disfavors coordination
22 Piers' osphonium Catalyst omero, P. E.; Piers, W. E.; McDonald,. Angew. Chem. Int. Ed. 2004, 43, Tf osphine donor is removed as vinylphosphonium species Et 2 C 3 steps - 25% 2 C C 2 methyl fumarate Tf Tf Ease of synthesis = Good
23 Piers' osphonium Catalyst omero, P. E.; Piers, W. E.; McDonald,. Angew. Chem. Int. Ed. 2004, 43, Tf osphine donor is removed as vinylphosphonium species Et 2 C 3 steps - 25% 2 C C 2 methyl fumarate Tf Tf Ease of synthesis = Good Tf initial metathesis event o preequilibrium event before metathesis can begin e-metathesis of vinylphosphonium salt essentially not possible
24 Piers' osphonium Catalyst omero, P. E.; Piers, W. E.; McDonald,. Angew. Chem. Int. Ed. 2004, 43, Tf osphine donor is removed as vinylphosphonium species Tf (F 3 C) 2 3 CC Mo (F 3 C) 2 3 CC Br Br
25 Piers' osphonium Catalyst omero, P. E.; Piers, W. E.; McDonald,. Angew. Chem. Int. Ed. 2004, 43, Tf osphine donor is removed as vinylphosphonium species Substrate Product Catalyst oading time (min) Conversion (%) Et 2 C C 2 Et Et 2 C C 2 Et 1.0 mol% < mol% mol% < Et 2 C C 2 Et Et 2 C C 2 Et 1.0 mol% < mol% Et 2 C C 2 Et Et 2 C C 2 Et 5.0 mol% <10 85
26 Catalysts Based on Improved lefin Binding eplacement of P 3 by a carbene donor markedly improved selectivity for olefin binding Could further alteration of the C donor provide further improvement? P 3 k 1 P 3 + P 3 k 2 + olefin olefin 1 k 1 k 2 k 2 k 2 k 3 k 3 1 k 3 k 3
27 Grubbs' Serendipitous bservations While attempting to develop an asymmetric catalyst, production of highly substituted olefins is observed Si catalyst (5 mol%) Si Si > 95% trisubstituted olefin 70% trisubstituted olefin 30% tetrasubstituted olefin Berlin, J. M. et al. rg. ett. 2007, 9, 1339.
28 C-igand ptimization Et 2 C C 2 Et catalyst (5 mol%) Et 2 C C 2 Et C 2 2, 30 C 11 t Bu t Bu t Bu t Bu 12 Berlin, J. M. et al. rg. ett. 2007, 9, 1339.
29 C-igand ptimization Applying the Blechert modification produces a highly active catalyst for the formation of tetrasubstituted olefins t Bu t Bu t Bu t Bu 12 t Bu t Bu t Bu t Bu 22 Berlin, J. M. et al. rg. ett. 2007, 9, 1339.
30 C-igand ptimization Most recently reported modification involves the tolyl-substitued C ligand 5 mol% catalyst 0.1M, C 6 D 6, 60 C Substrate Product Yield Substrate Product Yield E E E E >95% Ts Ts >95% E E E E >95% >95% E E E = C 2 Et E E 87% 88% Stewart, I. C. et. al J. Am. Chem. Soc. 2007, 9, 1589.
31 indered Cross-tathesis eactions Further ligand optimization has allowed for difficult cross-metathesis reactions to be successfully performed Bz + Ac Ac 3 mol% catalyst, reflux, 6h Bz Ac 38% 59% 87% Stewart, I. C.; Douglas, C. J.; Grubbs,.. rg. ett. ASAP.
32 indered Cross-tathesis eactions Further ligand optimization has allowed for difficult cross-metathesis reactions to be successfully performed Bz + Ac Ac 3 mol% catalyst, reflux, 6h Bz Ac 38% 59% 87% + Ac 5 mol% catalyst C 2 2, reflux, 24h Ac ESS efficient with dimethyl catalyst Why does the less bulky catalyst show lower reactivity when forming a trisubstituted olefin Stewart, I. C.; Douglas, C. J.; Grubbs,.. rg. ett. ASAP.
33 indered Cross-tathesis eactions The less sterically demanding catalyst may be performing rapid, but non-productive metathesis reactions Stewart, I. C.; Douglas, C. J.; Grubbs,.. rg. ett. ASAP.
34 indered Cross-tathesis eactions The less sterically demanding catalyst may be performing rapid, but non-productive metathesis reactions Could increasing the steric demand of the C ligand force desired olefin termini into contact? Steric interaction between substituted carbon atoms dominates Steric interaction with ortho ligand substituents dominates Stewart, I. C.; Douglas, C. J.; Grubbs,.. rg. ett. ASAP.
35 indered Cross-tathesis eactions The application of a carbene ligand with bulky groups in the ortho aryl positions results in efficient formation of trisubstituted olefins, but with some limitations. + Ac 5 mol% catalyst C 2 2, reflux, 24h Ac Substrate Product Yield Ac 98% Bz Bz Bz Bz Ac 96% Ac 7% Stewart, I. C.; Douglas, C. J.; Grubbs,.. rg. ett. ASAP.
36 General C Synthetic Scheme Three step synthesis transforms aniline into corresponding C Silver is typically used as a carbene transfer agent 2 (C) 2 B 3 C(Et) 3 1. Ag, C Grubbs' Gen. I itter, T.; Day, M. W.; Grubbs,.. J. Am. Chem. Soc. 2006, 128,
37 ther Catalyst Decomposition Pathways An increase in catalyst lifetime will positively influence any metathesis reaction Fogg group observes formation of triply chloride-bridges ruthenium species as a deactivation pathway 3 P P 3 3 P 3 P P 3 P 3 Substitution with pseudo-halide ligands yields efficient catalysts Currently, however, the syntheses of these catalysts is prohibitive I C 6 F 5 py C 6 F 5 I C 6 5 py I C 6 Br 5 py Br Conrad, J. C.; Fogg, D. E. Curr. rg. Chem. 2006, 10, 185. Amoroso, D.; Yap, G. A. P.; Fogg, D. E. rganometallics, 2002, 21, 3335.
38 eal World Examples (A Positive Sense) Et 2 C C 2 Et 5 mol% catalyst 0.1M, C 6 D 6, 60 C Et 2 C C 2 Et Sealed tube: 62% pen vessel (remove C 2 4 ): 87% Stewart, I. C. et. al J. Am. Chem. Soc. 2007, 9, mol% catalyst 43% yield Cy 3 P PMB 25 mol% catalyst 76% yield PMB Wood, J.. et al. J. Am. Chem. Soc. 2004, 126,
39 An Example with oom for Improvement PMB 10 mol% Grubbs Gen M, 35% yield PMB Trost, B. M.; Guangbin, G.; Vance, J. A. J. Am. Chem. Soc. 2007, 129, What three modifications would you make to this procedure as an attempt to improve yield?
40 An Example with oom for Improvement PMB 10 mol% Grubbs Gen M, 35% yield PMB Trost, B. M.; Guangbin, G.; Vance, J. A. J. Am. Chem. Soc. 2007, 129, What three modifications would you make to this procedure as an attempt to improve yield? First, run the reaction briefly at high concentration, followed by dilution to 0.001M
41 An Example with oom for Improvement PMB 10 mol% Grubbs Gen M, 35% yield PMB Trost, B. M.; Guangbin, G.; Vance, J. A. J. Am. Chem. Soc. 2007, 129, What three modifications would you make to this procedure as an attempt to improve yield? First, run the reaction briefly at high concentration, followed by dilution to 0.001M ext, try a phosphine-free commercial catalyst (i.e., oyveda-grubbs) at these conditions
42 An Example with oom for Improvement PMB 10 mol% Grubbs Gen M, 35% yield PMB Trost, B. M.; Guangbin, G.; Vance, J. A. J. Am. Chem. Soc. 2007, 129, What three modifications would you make to this procedure as an attempt to improve yield? First, run the reaction briefly at high concentration, followed by dilution to 0.001M ext, try a phosphine-free commercial catalyst (i.e., oyveda-grubbs) at these conditions Finally, if the reaction only slowly yields product, look to a more active catalyst (Blechert, Piers)
43 Applications in the MacMillan aboratory Formation of tetrasubstituted olefins is a significant extension for natural product synthesis Cross metathesis to form trisubstituted unsaturated aldehydes for anztch reduction may benefit from use of diisopropyl substituted catalyst + 5 mol% catalyst C 2 2, reflux, 24h Formation of complicated disubstituted unsaturated aldehydes may also benefit from the use of an altered C catalyst mol% catalyst C 2 2, reflux, 24h 2 Use of highly active catalysts may allow for significant reduction in catalyst loadings, potentially important for early-stage metathesis in total synthesis
44 Applications in the MacMillan aboratory Formation of tetrasubstituted olefins is a significant extension for natural product synthesis Cross metathesis to form trisubstituted unsaturated aldehydes for anztch reduction may benefit from use of diisopropyl substituted catalyst + 5 mol% catalyst C 2 2, reflux, 24h Formation of complicated disubstituted unsaturated aldehydes may also benefit from the use of an altered C catalyst mol% catalyst C 2 2, reflux, 24h 2 Use of highly active catalysts may allow for significant reduction in catalyst loadings, potentially important for early-stage metathesis in total synthesis
45 Applications in the MacMillan aboratory Formation of tetrasubstituted olefins is a significant extension for natural product synthesis Cross metathesis to form trisubstituted unsaturated aldehydes for anztch reduction may benefit from use of diisopropyl substituted catalyst + 5 mol% catalyst C 2 2, reflux, 24h Formation of complicated disubstituted unsaturated aldehydes may also benefit from the use of an altered C catalyst mol% catalyst C 2 2, reflux, 24h 2 Use of highly active catalysts may allow for significant reduction in catalyst loadings, potentially important for early-stage metathesis in total synthesis
46 Applications in the MacMillan aboratory Formation of tetrasubstituted olefins is a significant extension for natural product synthesis Cross metathesis to form trisubstituted unsaturated aldehydes for anztch reduction may benefit from use of diisopropyl substituted catalyst + 5 mol% catalyst C 2 2, reflux, 24h Formation of complicated disubstituted unsaturated aldehydes may also benefit from the use of an altered C catalyst mol% catalyst C 2 2, reflux, 24h 2 Use of highly active catalysts may allow for significant reduction in catalyst loadings, potentially important for early-stage metathesis in total synthesis
47 tathesize Smarter, not arder Slight changes to substrate structure and reaction conditions may yield significant gains Many recently reported catalysts are easily synthesized Careful consideration of each specific metathesis challenge can guide investigations Br Tf Br Don't be afraid to use cutting edge metathesis technology
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
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
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
Electrophilic Carbenes
Electrophilic Carbenes The reaction of so-called stabilized diazo compounds with late transition metals produces a metal carbene intermediate that is electrophilic. The most common catalysts are Cu(I)
Dr. P. Wipf Page 1 of 5 10/7/2009. Cl Ru. Kingsbury, J. S.; Harrity, J. P. A.; Hoveyda, A. H. J. Am. Chem. Soc. 1999, 121, 791.
Dr. P. Wipf Page 1 of 5 10/7/2009 Alkene Metathesis Grubbs II published The Catalysts Me Mo F 3C CF3 Me F 3C CF3 C(Me) 2 chrock, R. R.; Murdzek, J..; Bazan, G. C.; Robbins, J.; DiMare, M.; 'Reagan, M.
Sonogashira: in situ, metal assisted deprotonation
M.C. White, Chem 253 Cross-Coupling -120- Week of ctober 11, 2004 Sonogashira: in situ, metal assisted deprotonation catalytic cycle: ' (h 3 ) n d II The first report: h Sonogashira T 1975 (50) 4467. h
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
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,
Strained Molecules in Organic Synthesis
Strained Molecules in rganic Synthesis 0. Introduction ~ featuring on three-membered rings ~ Tatsuya itabaru (M) Lit. Seminar 08068 for cyclobutadienes : see Mr. Yamatsugu's Lit. Sem. 069 eat of Formation
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
Catalytic Asymmetric [4+1] Annulation of Sulfur Ylides with Copper Allenylidene Intermediates. Reporter: Jie Wang Checker: Shubo Hu Date: 2016/08/02
![Catalytic Asymmetric [4+1] Annulation of Sulfur Ylides with Copper Allenylidene Intermediates. Reporter: Jie Wang Checker: Shubo Hu Date: 2016/08/02](/thumbs/93/114018431.jpg "Catalytic Asymmetric [4+1] Annulation of Sulfur Ylides with Copper Allenylidene Intermediates. Reporter: Jie Wang Checker: Shubo Hu Date: 2016/08/02")
Catalytic Asymmetric [4+1] Annulation of Sulfur Ylides with Copper Allenylidene Intermediates Reporter: Jie Wang Checker: Shubo Hu Date: 2016/08/02 Xiao, W.-J. et al. J. Am. Chem. Soc. 2016, 138, 8360.
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,
GRUBBS CATALYST C571. For Ring-closing Metathesis Of Sterically Challenging Substrates GRUBBS CATALYST C571. Cl 2.
C57 C57 For Ring-closing Metathesis f Sterically Challenging Substrates C 7 H 0 Cl Ru Dichloro[,-bis(-methylphenyl)- -imidazolidinylidene] (-isopropoxyphenylmethylene) ruthenium(ii) CM RCM RMP RMP Ring
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
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.
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
Nine-Step Enantioselective Total Synthesis of (+)-Minfiensine
ine-step nantioselective Total Synthesis of (+)-Minfiensine Jones, S. B.; Simmons, B.; MacMillan, D. W. C.* J. Am. Chem. Soc. 2009, ASAP. DI: 10.1021/ja906472m Kara George Wipf Group - Current Literature
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
Deactivation Pathways in Transition Metal Catalysis
Deactivation Pathways in Transition tal Catalysis Why Study Catalyst Decomposition? decomposition active for catalysis inactive for catalysis "One of the reasons for [the] limited understanding [of catalyst
Negishi Coupling of Secondary Alkylzinc Halides with Aryl Bromides and Chlorides
Negishi Coupling of Secondary Alkylzinc alides with Aryl Bromides and Chlorides X X = Br, Cl 2 1 ZnBr 1, 2 = Alkyl Cat. Pd(OAc) 2 Ligand TF/Toluene rt or 60 o C 1 2 J. Am. Chem. Soc. 2009, ASAP Article
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
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.
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,
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
Oxidative Addition and Reductive Elimination
xidative Addition and Reductive Elimination red elim coord 2 ox add ins Peter.. Budzelaar xidative Addition Basic reaction: n + X Y n X Y The new -X and -Y bonds are formed using: the electron pair of
Synthetic Methodology. Using Tertiary Phosphines. as Nucleophilic Catalysts
Synthetic Methodology Using Tertiary osphines as Nucleophilic Catalysts 1 3 2 u 2 (P 3 ) 3 4 1 2 D. Ma, X. Lu 1988 1 2 Pd 2 (dba) 3.CCl 3 /P 3 /Ac or Pd(Ac) 2 /P 3 1 2 B. M. Trost 1988 1 3 2 u 2 (P 3 )
Asymmetric Synthesis of Medium-Sized Rings by Intramolecular Au(I)-Catalyzed Cyclopropanation
Asymmetric Synthesis of Medium-Sized ings by Intramolecular Au(I)-Catalyzed Cyclopropanation 1 2 Iain D. G. Watson, Stefanie itter, and F. Dean Toste JACS, ASAP, 1/22/2009 DI: 10.1021/ja8085005 2.5 mol%
Reaction chemistry of complexes Three general forms: 1. Reactions involving the gain and loss of ligands a. Ligand Dissoc. and Assoc. (Bala) b.
eaction chemistry of complexes Three general forms: 1. eactions involving the gain and loss of ligands a. Ligand Dissoc. and Assoc. (Bala) b. Oxidative Addition c. eductive Elimination d. Nucleophillic
Asymmetric Nucleophilic Catalysis
Asymmetric ucleophilic Catalysis Chiral catalyst X 2 Chiral catalyst X = alkyl, X 1 2 1 Vedejs, E.; Daugulis,. J. Am. Chem. Soc. 2003, 125, 4166-4173 Shaw, S. A.; Aleman,.; Vedejs, E. J. Am. Chem. Soc.
N-Heterocyclic Carbenes (NHCs)
N-Heterocyclic Carbenes (NHCs) In contrast to Fischer and Schrock type carbenes NHCs are extremely stable, inert ligands when complexed to a metal centre. Similar to phosphine ligands they are electronically
Chapter 2 The Elementary Steps in TM Catalysis
hapter 2 The Elementary Steps in TM atalysis + + ligand exchange A oxidative addition > n + A B n+2 reductive elimination < B n n+2 oxidative coupling + M' + M' transmetallation migratory insertion > (carbo-,
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
Carbenes and Carbene Complexes I Introduction
Carbenes and Carbene Complexes I Introduction A very interesting (honest) class of radical-like molecules Steadily becoming more important as they find far more synthetic applications We will primarily
Organo-transition Metal Chemistry
Prof. Dr. Burkhard König, nstitut für rganische Chemie, Universität egensburg 1 rgano-transition tal Chemistry 1. Some Basics Chemistry involves intermediates containing transition-metal carbon bonds tal-carbon
Organometallic Catalysis
Organometallic Catalysis The catalysts we will study are termed homogeneous catalysts as they are dissolved in th e same solvent as the substrate. In contrast, heterogeneous catalysts, such as palladium
Iridium-Catalyzed Hydrogenation with Chiral P,N Ligands
Iridium-Catalyzed Hydrogenation with Chiral P, Ligands 贾佳 utline Brief Introduction Hydrogenation of C=C Bonds Hydrogenation of C= Bonds Hydrogenation of C= Bonds Conclusion Brief Introduction First example
DESYMMETRIZATION THROUGH ENANTIOSELECTIVE OLEFIN METATHESIS
DESYMMETIZATI TUG EATISELECTIVE LEFI METATESIS Min Xie ovember 18, 2004 ITDUCTI lefin metathesis is defined as the redistribution of carbon-carbon double bonds, and is catalyzed by metal carbene complexes.
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
Metal Hydrides, Alkyls, Aryls, and their Reactions
Metal Hydrides, Alkyls, Aryls, and their Reactions A Primer on MO Theory σ-bonding in Organotransition Metal Complexes M-C Bond Energies in Organotransition Metal Complexes Thermodynamic Predictions
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
Homogeneous Catalysis - B. List
omogeneous Catalysis - B. List 2.2.2 Research Area "rganocatalytic Asymmetric α-alkylation of Aldehydes" (B. List) Involved:. Vignola, A. Majeed Seayad bjective: α-alkylations of carbonyl compounds are
Branched-Regioselective Hydroformylation with Catalytic Amounts of a Reversibly Bound Directing Group
1/12 Branched-egioselective ydroformylation with Catalytic Amounts of a eversibly Bound Directing Group h(i)/me C/ 2 MS 4A branched major by Christian U. Grünanger and Bernhard Breit Angew. Chem. Int.
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
Chapter 1. Ring-Opening Cross-Metathesis of Low-Strain Cycloolefins
1 Chapter 1. Ring-Opening Cross-Metathesis of Low-Strain Cycloolefins Abstract The ring-opening cross-metathesis (ROCM) of five- through eight-membered ring cycloolefins, catalyzed by a ruthenium alkylidene
Stable gold(iii) catalysts by oxidative addition of a carboncarbon
Stable gold(iii) catalysts by oxidative addition of a carboncarbon bond Chung-Yeh Wu, Takahiro oribe, Christian Borch Jacobsen & F. Dean Toste ature, 517, 449-454 (2015) presented by Ian Crouch Literature
N-Heterocyclic Carbenes (NHCs)
N-Heterocyclic Carbenes (NHCs) In contrast to Fischer and Schrock type carbenes NHCs are extremely stable, inert ligands when complexed to a metal centre. Similar to phosphine ligands they are electronically
Module 6 : General properties of Transition Metal Organometallic Complexes. Lecture 2 : Synthesis and Stability. Objectives
Module 6 : General properties of Transition Metal Organometallic Complexes Lecture 2 : Synthesis and Stability Objectives In this lecture you will learn the following Understand the role lead by ligands
Copper-Catalyzed Reaction of Alkyl Halides with Cyclopentadienylmagnesium Reagent
Copper-Catalyzed eaction of Alkyl Halides with Cyclopentadienylmagnesium eagent Mg 1) cat. Cu(Tf) 2 i Pr 2, 25 o C, 3 h 2) H 2, Pt 2 Masahiro Sai, Hidenori Someya, Hideki Yorimitsu, and Koichiro shima
Catellani Reaction (Pd-Catalyzed Sequential Reaction) Todd Luo
Catellani Reaction (Pd-Catalyzed Sequential Reaction) Todd Luo 2014.1.6 1 Content Introduction Progress of Catellani Reaction o-alkylation and Applications o-arylation and Applications Conclusion and Outlook
Palladium-Catalyzed Oxygenation of Unactivated sp 3 C-H Bonds
Palladium-Catalyzed xygenation of Unactivated sp 3 C- Bonds Pd(Ac) 2 5 mol% PhI(Ac) 2 1.1 eq. Pd 2 Ac Desai, L. P.; ull, K. L.; Sanford *, M. S. University of Michigan J. Am. Chem. Soc. 2004, 126, ASAP
A Simple Introduction of the Mizoroki-Heck Reaction
A Simple Introduction of the Mizoroki-Heck Reaction Reporter: Supervisor: Zhe Niu Prof. Yang Prof. Chen Prof. Tang 2016/2/3 Content Introduction Intermolecular Mizoroki-Heck Reaction Intramolecular Mizoroki-Heck
Spiro Monophosphite and Monophosphoramidite Ligand Kit
Spiro Monophosphite and Monophosphoramidite Ligand Kit metals inorganics organometallics catalysts ligands custom synthesis cgm facilities nanomaterials 15-5162 15-5150 15-5156 15-5163 15-5151 15-5157
Intramolecular Ene Reactions Utilizing Oxazolones and Enol Ethers Fisk, J.S. and Tepe, J..J J. Am. Chem. Soc., 2007, 129,
Intramolecular Ene Reactions Utilizing xazolones and Enol Ethers Fisk, J.S. and Tepe, J..J J. Am. Chem. Soc., 2007, 129, 3058-3059 - versus -Arylation of Aminoalcohols: rthogonal Selectivity in Copper-Based
Mild Cobalt-Catalyzed Hydrocyanation of Olefins with Tosyl Cyanide
Mild Cobalt-Catalyzed ydrocyanation of lefins with Tosyl Cyanide 1 3 2 + Ts Co cat., Si 3 Et, 1-3 h, T 1 2 3 Gaspar, B.; Carreira, E. M. Angew. Chem. Int. Ed. ASAP Current Literature Kalyani Patil 12 May
Three Type Of Carbene Complexes
Three Type f arbene omplexes arbene complexes have formal metal-to-carbon double bonds. Several types are known. The reactivity of the carbene and how it contributes to the overall electron counting is
ASYMMETRIC PALLADIUM-CATALYZED ALKENE CARBOAMINATION REACTIONS FOR THE SYNTHESIS OF CYCLIC SULFAMIDES
AYMMETIC PALLADIUM-CATALYZED ALKEE CABAMIATI EACTI F TE YTEI F CYCLIC ULFAMIDE Chem. Eur. J. 2016, 22, 5919 5922 Zachary J. Garlets, Kaia. Parenti, and John P. Wolfe James Johnson Wipf Group Current Literature
Functionalization of C(sp 3 ) H Bonds Using a Transient Directing Group
Literature eport Functionalization of C(sp 3 ) Bonds Using a Transient Directing Group eporter: Mu-Wang Chen Checker: Yue Ji Date: 2016-04-05 Yu, J.-Q. et al. Science 2016, 351, 252-256. Scripps esearch
o-palladated cat. [Chem. Comm (1999)] [Org. Lett. 2, 1826 (2000)] [Org. Lett. 2, 2881 (2000)] [JACS 41, 9550 (1999)]
![o-palladated cat. [Chem. Comm (1999)] [Org. Lett. 2, 1826 (2000)] [Org. Lett. 2, 2881 (2000)] [JACS 41, 9550 (1999)]](/thumbs/85/92754396.jpg "o-palladated cat. [Chem. Comm (1999)] [Org. Lett. 2, 1826 (2000)] [Org. Lett. 2, 2881 (2000)] [JACS 41, 9550 (1999)]")
3. Boron -- eview [Suzuki Chem. ev. 95, 2457 (1995)] U77b ydroboration also attractive but B Pd transmetallation difficult - must produce stable B product - solved (by Suzuki) by adding base to make Borates
There are 15 total pages to this exam. Please be sure your copy has 15 pages before you begin.
Initials: 1 ame: Chem 633: Advanced rganic Chemistry Midterm 2 Please answer the following questions clearly and concisely. Write your answers in the space provided. Write your initials on each page you
a-aminoallylation of Aldehydes with Ammonia: Stereoselective Synthesis of Homoallylic Primary Amines
a-aminoallylation of Aldehydes with Ammonia: Stereoselective Synthesis of omoallylic Primary Amines 1 3 2 3 ML n 1 2 2 3 Masaharu Sugiura, Keiichi irano and Shu Kobayashi JACS ASAP ryan Wakefield @ Wipf
Development of Chiral Phosphine Olefin Ligands and Their Use in Asymmetric Catalysis
Development of Chiral osphine lefin Ligands and Their Use in Asymmetric Catalysis 2 Wei-Liang Duan July 31, 2007 Research Works in Hayashi Group, Kyoto University (ct, 2003 Mar, 2007) Conventional Chiral
Initials: 1. Chem 633: Advanced Organic Chemistry 2011 Final Exam
Initials: 1 ame: Chem 633: Advanced rganic Chemistry 2011 Final Exam Please answer the following questions clearly and concisely. In general, use pictures and less than 10 words in your answers. Write
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
Domino Reactions in Total Synthesis! Reporter: Tianhe Yang! Supervisors: Prof. Yang! Prof. Chen! Prof. Tang!
1! Domino Reactions in Total Synthesis! Reporter: Tianhe Yang! Supervisors: Prof. Yang! Prof. Chen! Prof. Tang! 2! utline! 1. Brief Introduction! 2. ucleophilic Dominoes! 3. Electrophilc Dominoes! 4. Radical
A New Strategy for Efficient Synthesis of Medium and Large Ring Lactones without High Dilution or Slow Addition
A ew Strategy for Efficient Synthesis of Medium and Large ing Lactones without High Dilution or Slow Addition BF 3 Et 2 TIPS 2,4,6-collidine n + n+2 ' ' Zhao, W.; Li, Z; Sun, J. J. Am. Chem. Soc. 2013
CEM 852 Final Exam. May 6, 2010
CEM 852 Final Exam May 6, 2010 This exam consists of 7 pages. Please make certain that your exam has all of the necessary pages. Total points possible for this exam are 150. n answering your questions,
Amines. Amines are organic compounds containing a nitrogen functionality. primary secondary tertiary quaternary
Amines Amines are organic compounds containing a nitrogen functionality Depending upon the number of alkyl, or aryl, groups attached to nitrogen determines its classification, or order 2 primary secondary
Repeated insertion. Multiple insertion leads to dimerization, oligomerization or polymerization. κ 1: mainly dimerization κ
Repeated insertion ultiple insertion leads to dimerization, oligomerization or polymerization. k prop Et Key factor: k CT / k prop = κ κ 1: mainly dimerization κ 0.1-1.0: oligomerization (always mixtures)
Planar-Chiral Phosphine-Olefin Ligands Exploiting a (Cyclopentadienyl)manganese(I) Scaffold to Achieve High Robustness and High Enantioselectivity
Planar-Chiral Phosphine-Olefin Ligands Exploiting a (Cyclopentadienyl)manganese(I) Scaffold to Achieve High Robustness and High Enantioselectivity Reporter: Cong Liu Checker: Hong-Qiang Shen Date: 2017/02/27
N-HETEROCYCLIC CARBENES: STRUCTURE AND PROPERTIES
N-HETEROCYCLIC CARBENES: STRUCTURE AND PROPERTIES Zachery Matesich 24 February 2015 Roadmap 2 Introduction Synthetic Methods History of NHCs Properties of NHCs Nature of the carbene Structural properties
Copper-Catalyzed Synthesis of Esters from Ketones. Alkyl Group as a Leaving Group.
Copper-Catalyzed Synthesis of Esters from Ketones. Alkyl Group as a Leaving Group. akatani, Y.; Koizumi, Y.; Yamasaki, R.; Saito, S. rg. Lett. 2008, 10, 2067-2070. An Annulation Reaction for the Synthesis
"-Amino Acids: Function and Synthesis
"-Amino Acids: Function and Synthesis # Conformations of "-Peptides # Biological Significance # Asymmetric Synthesis Sean Brown MacMillan Group eting ovember 14, 2001 Lead eferences: Cheng,. P.; Gellman,
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
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 ' '' ' ' ' ' '
Literature Report I. Total Synthesis of (+)-Piperarborenine B. Reporter: Zheng Gu. Date:
Literature Report I Total Synthesis of (+)-Piperarborenine B Reporter: Zheng Gu Checker: Bo Song Date: 2016-12-12 Hu, J. L.; Xie, Z. W.; Tang, Y. J. Am. Chem. Soc. 2016, 138, 13151. Panish, R. A.; Chintala,
Organocopper Chemistry
rganocopper Chemistry ave a great historical importance, but still remain highly useful reactions. If not the first organometallic reactions developed they are among the first. Most often used in conjugate
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
Chapter 5 Three and Four-Membered Ring Systems
Chapter 5 Three and Four-mbered ing ystems 5.1 Aziridines Aziridines are good alkylating agents because of their tendency to undergo ring-opening reaction with nucleophiles 例 mitomycin C antibiotic and
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
O CH 3. Mn CH 3 OC C. 16eelimination
igratory Insertion igratory Insertion/Elimination 1 A migratory insertion reaction is when a cisoidal anionic and neutral ligand on a metal complex couple together to generate a new coordinated anionic
π-alkyne metal complex and vinylidene metal complex in organic synthesis
Literature Seminar 080220 Kenzo YAMATSUGU (D1) π-alkyne metal complex and vinylidene metal complex in organic synthesis 0. Introduction ' ' = π-alkyne metal complex vinylidene metal complex ecently, electrophilic
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
ACTIVATION OF C H BONDS BY LOW-VALENT METAL COMPLEXES ( THE ORGANOMETALLIC CHEMISTRY )
CHAPTER IV ACTIVATION OF C H BONDS BY LOW-VALENT METAL COMPLEXES ( THE ORGANOMETALLIC CHEMISTRY ) n the end of the 1960s the leading specialist in homogeneous catalysis Jack Halpern wrote [1]: to develop
Free Radical Reactions in Synthetic Organic Chemistry
Free adical eactions in ynthetic rganic Chemistry C549.M. Williams Free radical intermediates have been utilized with varying degrees of success in the stereocontrolled formation of C-C bonds. Among the
Disulfonimide-Catalyzed Asymmetric Vinylogous and Bisvinylogous Mukaiyama Aldol Reactions
Disulfonimide-Catalyzed Asymmetric Vinylogous and Bisvinylogous Mukaiyama Aldol eactions atjen, L. Garcia-Garcia, P., Lay, F., Beck, M. E., List, B.; Angew. Chem. Int. Ed. 2010, ASAP. Convergent Total
The version of SI posted May 6, 2004 contained errors. The correct version was posted October 21, 2004.
The version of SI posted May 6, 2004 contained errors. The correct version was posted October 21, 2004. Sterically Bulky Thioureas as Air and Moisture Stable Ligands for Pd-Catalyzed Heck Reactions of
Organic Tutorials 3 rd Year Michaelmas Transition Metals in Organic Synthesis: (General paper level) ! 1! Reading
rganic Tutorials 3 rd Year Michaelmas 2010 Transition Metals in rganic Synthesis: (General paper level) Reading 1. Lecture Course, and suggested references from this. 2. Clayden, Greaves, Warren and Wothers.
Reductive Elimination
Reductive Elimination Reductive elimination, the reverse of oxidative addition, is most often seen in higher oxidation states because the formal oxidation state of the metal is reduced by two units in
Literature Report III
Literature Report III Regioselective ydroarylation of Alkynes Reporter: Zheng Gu Checker: Cong Liu Date: 2017-08-28 Cruz, F. A.; Zhu, Y.; Tercenio, Q. D.; Shen, Z.; Dong, V. M. J. Am. Chem. Soc. 2017,
Keisuke Suzuki. Baran lab Group Meeting 6/11/16. Shigenobu Umemiya. Akira Suzuki. Takanori Suzuki (Hokkaido University)
197.D., Teruaki Mukaiyama, University of Tokyo 193 Assistant Professor, Keio University 197 Lecturer, Keio University 199 Assocate Professor, Keio University 1990 Visiting Professor, ET 1994 ull Professor,
Asymmetric Lewis Base Strategies for Heterocycle Synthesis
Asymmetric Lewis Base trategies for eterocycle ynthesis Dr Andrew mith EatCEM, chool of Chemistry, University of t Andrews 1st cottish-japanese ymposium of rganic Chemistry, University of Glasgow Friday
Total synthesis of Spongistatin
Literature Semminar 1. Introduction: Total synthesis of Spongistatin Chen Zhihua (M2) Isolation: Pettit et al. J. rg. Chem. 1993, 58, 1302. Kitagawa et al. Tetrahedron Lett. 1993, 34, 1993. Fusetani et
HYDROGENATION. Concerned with two forms of hydrogenation: heterogeneous (catalyst insoluble) and homogeneous (catalyst soluble)
YDGEATI Concerned with two forms of hydrogenation: heterogeneous (catalyst insoluble) and homogeneous (catalyst soluble) eterogeneous Catalysis Catalyst insoluble in reaction medium eactions take place
NIH Public Access Author Manuscript Org Lett. Author manuscript; available in PMC 2013 December 24.
NIH Public Access Author Manuscript Published in final edited form as: Org Lett. 2010 March 5; 12(5):. doi:10.1021/ol9029808. Low Catalyst Loadings in Olefin Metathesis: Synthesis of Nitrogen Heterocycles
The Mechanism of Pd-Catalyzed Amination Controversy.. And Conclusion?
The chanism of d-catalyzed Amination Controversy.. And Conclusion? R H R1 R 2 d(dba) 2 BIA, h R R1 R 2 Steve Tymonko SED Group eting 5/9/06 d-catalyzed Amination- Tin Initial Report- Kosugi, 1983 n-bu
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
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
Denmark s Base Catalyzed Aldol/Allylation
Denmark s Base Catalyzed Aldol/Allylation Evans Group Seminar ovember 1th, 003 Jimmy Wu Lead eferences: Denmark, S. E. Acc. Chem. es., 000, 33, 43 Denmark, S. E. Chem. Comm. 003, 167 Denmark, S. E. Chem.
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
Short Literature Presentation 10/4/2010 Erika A. Crane
Copper-Catalyzed Enantioselective Synthesis of trans-1- Alkyl-2-substituted Cyclopropanes via Tandem Conjugate Additions-Intramolecular Enolate Trapping artog, T. D.; Rudolph, A.; Macia B.; Minnaard, A.