A Brief Survey on Synthesis and Catalytic Reactivity of Metal-Metal Bond Complexes
|
|
|
- Basil Greer
- 5 years ago
- Views:
Transcription
1 A ief Survey on Synthesis and Catalytic Reactivity of tal-tal Bond Complexes Chi Chip Le MacMillan Research Group Group eting Presentation April 6th, 2017
2 Synthesis and Catalytic Reactivity of tal-tal Bond Complexes istory of the pursuit of the shortest metal-metal bond Cr 2 (OAc) 4!2 2 O K 2 [Re 2 8 ] Cr 2 Ar 2 Catalytic reactivity of metal-metal bond complexes [ 2 (μ-) 2 (PBu t 3) 2 ] (C)-Cp() 2 (" 3 -methallyl)(pr 3 )Ti 2
3 istory of the Pursuit of the Shortest tal-tal Bond The concept of a single metal ion surrounded by a set of ligands Co Co Co Alfred Werner One-center coordination chemistry (1900) Multicenter coordination chemistry (1963) First isolation by Peligot (1844) First X-ray by Cotton (1970) F. A. Cotton Cr 2 (OAc) 4!2 2 O Cr Cr Quadruple Bond
4 istory of the Pursuit of the Shortest tal-tal Bond Tronev (1952) Cotton (1965) KReO 4 (conc.) 2 (50 atm) reflux (conc.) K 2 [Re 2 8 ] 3 PO 2 (50% aq) KReO 4 reflux Re 3+ diamagnetic compound Eclipse conformation of chloride ligands Very short Re-Re bond distance of 2.24 Å First proposal for a Re Re quadruple bond Proposed ground state configuration: σ 2 π 4 δ 2 Structure of [Re 2 8 ] 2- as reported by Cotton et al. Cotton, F. A.; arris, C. B. norg. Chem. 1965, 4, 330. (1964 and 1965) Cotton, F. A.; rtis,. F., Johnson, B. F. G.; Robinson, W. R. norg. Chem. 1965, 4, 326. Cotton, F. A.; rtis,. F., arris, C. B.; Johnson, B. F. G. et al Science 1964, 145, Bondin. S. M.; Tronev, V. G. Dokl. Akad. auk SSSR 1952, 86, 87. Cotton, F. A.; Murillo, L. A.; Walton, R. A. Multiple Bonds Between tal Atoms 3rd edn (Springer, 2005).
5 istory of the Pursuit of the Shortest tal-tal Bond [Re4]δ* δ* dx2-y2 δ (dxy dxy) δ δ σ* π* π* δ* π (dxz dxz) π (dyz dyz) dxz, dyz δ dxy, dz2 π π σ (dz2 dz2) σ McGrady, J. E. Molecular tal-tal Bonds (Wiley, 2015). Blaudeau, J.-P.; Ross, R. B.; Pitzer, R. M.; Mougenot, P.; Bénard, M. J. ys. Chem. 1994, 98, 7123.
6 istory of the Pursuit of the Shortest tal-tal Bond The shortest metal-metal bond for almost 30 years (Cotton, 1978) O Li O TF, 25 C O Cr Cr O 2 O O Cr 2 (OAc) 4 2 Cr-Cr bond = Å (ipr 2 ) First quintuple bond ever reported (ipr 2 ) Cr Cr Unique trans-bent conformation (ipr 2 ) (ipr 2 ) Ground state configuration: σ 2 π 4 δ 4 Cr-Cr bond = Å Bond length depends more on the ligand framework constraint guyen, T.; Power, P. P. et al Science 2005, 310, 844. Cotton, F. A.; Koch, S. A.; Millar, M. norg. Chem. 1978, 17, 2084.
7 istory of the Pursuit of the Shortest tal-tal Bond (ipr 2 ) (ipr 2 ) (ipr 2 ) Cr Cr (ipr 2 ) (ipr 2 ) (ipr 2 ) Theopold & Landis (2007) Quintuple Cr-Cr = Å Cr Cr (ipr 2 ) (ipr 2 ) Cy Cy Cr (TMS) 2 Cr (TMS) 2 Kempe (2013) Quintuple Cr-Cr = Å Cy Cy Gambarotta (2008) Quadruple Cr-Cr = Å Shortest metal-metal bond ever reported to date! Cotton (1978) Å Power (2005) Å Å Å Å air, A, K,; arisomayajula,. V. S.; Tsai, Y.-C. norg. Chim. Acta 2015, 424, 51.
8 Synthesis and Catalytic Reactivity of tal-tal Bond Complexes istory of the pursuit of the shortest metal-metal bond Cr 2 (OAc) 4!2 2 O K 2 [Re 2 8 ] Cr 2 Ar 2 Cotton et al (2005) Liddle et al (2015)
9 Synthesis and Catalytic Reactivity of tal-tal Bond Complexes istory of the pursuit of the shortest metal-metal bond Cr 2 (OAc) 4!2 2 O K 2 [Re 2 8 ] Cr 2 Ar 2 Catalytic reactivity of metal-metal bond complexes [ 2 (μ-) 2 (PBu t 3) 2 ] (C)-Cp() 2 (" 3 -methallyl)(pr 3 )Ti 2
10 Catalytic Reactivity of tal-tal Bond Complexes 0 O PCy 2 0 O Coordinately unsaturated (0) complex ighly reactive catalysts for cross coupling Maintaining 1:1 M:L is crucial to high reactivity - 2 P(t-Bu) 3 0 Pt-Bu 3 ighly reactive catalyst for cross coupling with aryl chlorides 2 (μ-) 2 (Pt-Bu 3 ) 2 First reported by Mingos (1996) () dimer could serve as air-stable (0) precatalyst 0 (dba) 2 / Pt-Bu 3 Conventional precursor Vilar, R.; Mingos, D. M. P.; Cardin, C. J. J. Chem. Soc., Dalton Trans. 1996, 4314.
11 Catalytic Reactivity of tal-tal Bond Complexes R R mol% () dimer R = o-, O, C, O equiv aot-bu, TF 15 min R R 2 88 to 99% yield t-bu 3 P Pt-Bu 3 () dimer () dimer 0 Pt-Bu 3 Rapid release of active monoligated (0) Disproportionation, dissociation or reduction? What is the mode of activation to access (0)? What about a bimetallic catalysis scenario? Rate studies on the amination of 3-bromothiophene with different 0 PtBu 3 sources ooper, M. W.; Utsunomiya, M.; artwig, J. F. J. Org. Chem. 2003, 68, Stambuli, J. P.; Kuwano, R.; artwig, J. F. Angew. Chem. nt. Ed. 2002, 41, 4746.
12 Catalytic Reactivity of tal-tal Bond Complexes 0 Pt-Bu 3 + Pt-Bu 3 2 t-bu 3 P Pt-Bu 3 Disproportionation () dimer Pt-Bu 3 + Pt-Bu 3 Dissociation 0 (Pt-Bu 3 ) 2 0 Pt-Bu 3 + Pt-Bu 3 G = 27.2 kcal/mol (DFT) Often considered the rate-limiting step in (dba) / Pt-Bu 3 protocols Since rate () dimer is more reactive, disproportionation should be more favorable () dimer 0 Pt-Bu 3 + Pt-Bu 3 2 G = 38.1 kcal/mol (DFT) The general assumption that () dimer directly disproportionate to (0) in solution seems unlikely Proutiere, F.; Aufiero, M.; Schoenebeck, F. J. Am. Chem. Soc. 2012, 134, 606.
13 Catalytic Reactivity of tal-tal Bond Complexes 0 Pt-Bu 3 + Pt-Bu 3 2 t-bu 3 P Pt-Bu 3 Disproportionation () dimer Pt-Bu 3 + Pt-Bu 3 Dissociation () dimer Pt-Bu 3 + Pt-Bu 3 G = 24.8 kcal/mol (DFT) DFT calculation suggests (0) and () should have different selectivity toward Ar-X oxidative addition 0 Pt-Bu 3 Ar oxidative addition is favored by 9.8 kcal/mol (DFT) Pt-Bu 3 ArOTf oxidative addition is favored by 8.4 kcal/mol (DFT) 1.5 mol% () dimer OTf Ar OTf ArB(O) 2, KF, TF 70% yield Ar Dissociation pathway is unlikely 0% yield Proutiere, F.; Aufiero, M.; Schoenebeck, F. J. Am. Chem. Soc. 2012, 134, 606.
14 Catalytic Reactivity of tal-tal Bond Complexes t-bu 3 P Pt-Bu 3 [ 0 Pt-Bu 3 X] 0 Pt-Bu 3 or Studies of reduction pathway have not been reported Ar- oxidative addition t-bu 3 P Ar Pt-Bu 3 s Bimetallic Catalysis Possible with () Dimer? t-bu 3 P Pt-Bu 3 t-bu 3 P Pt-Bu 3 TF 25 C () dimer remains intact, zero reactivity Bimetallic catalysis is not operative for aryl chloride/bromide coupling t-bu 3 P Pt-Bu 3 Bimetallic O.A. and R.E.? Bonney, K. J.; Proutiere, F.; Schoenebeck, F. Chem. Sci. 2013, 4, Proutiere, F.; Aufiero, M.; Schoenebeck, F. J. Am. Chem. Soc. 2012, 134, 606. Seechurn, C. C. C. J.; Sperger, T.; Scrase, T. G.; Schoenebeck, F.; Colacot, T. J. J. Am. Chem. Soc. 2017, ASAP.
15 Catalytic Reactivity of tal-tal Bond Complexes aryl iodide () dimer (20 mol%) Bu 4 (10 eq), TF 81% yield, 96 h t-bu 3 P Pt-Bu 3 () dimer t-bu 3 P Ar Pt-Bu 3 Single () does not readily undergo reductive elimination aryl iodide () Dimer Catalytic aryl bromide Ar Pt-Bu 3 2, Pt-Bu 3 Ar t-bu 3 P Pt-Bu 3 Cycle t-bu 3 P Pt-Bu 3 Formation of - bond lowers the activation barrier for R.E. Bu 4 Bu 4 Bonney, K. J.; Proutiere, F.; Schoenebeck, F. Chem. Sci. 2013, 4, 4434.
16 Catalytic Reactivity of tal-tal Bond Complexes () dimer (20 mol%) t-bu3p Bu4 (10 eq), TF () dimer aryl iodide 81% yield, 96 h t-bu3p Pt-Bu3 Ar Pt-Bu3 t-bu3p Pt-Bu3 TS for O.A. and R.E. () Dimer aryl iodide aryl bromide Catalytic Cycle t-bu3p Pt-Bu3 t-bu3p Pt-Bu3 Bu4 Bu4 Bonney, K. J.; Proutiere, F.; Schoenebeck, F. Chem. Sci. 2013, 4, 4434.
17 Catalytic Reactivity of tal-tal Bond Complexes () dimer (2 mol%) / SCF 3 4 SCF 3 (1.5 eq) 27 examples 65 to 99% yield () dimer (5 mol%) SeCF 3 4 SeCF 3 (2.0 eq) 20 examples 62 to 99% yield / R () dimer (0.75 mol%) DPEA (1.1 eq) R 20 examples 46 to 99% yield () dimer can serve as an air-stable, reusable catalyst with enhanced reactivity Sperger, T.; Stierner, C. K.; Schoenebeck, F. Synthesis 2017, 49, 115. Yin, G.; Kalvet,.; Schoenebeck, F. Angew. Chem. nt. Ed. 2015, 54, Aufiero, M.; Sperger, T.; Tsang, A. S.-K.; Schoenebeck, F. Angew. Chem. nt. Ed. 2015, 54,
18 Catalytic Reactivity of tal-tal Bond Complexes First synthesis of heterobimetallic Ti complex (agashima, 2009) tbu (Acetone) 2 OTf + Ti tbu P 2 P 2 Ti P P tbu tbu OTf P P tbu tbu OMO-1 d z 2 d z 2 P P tbu tbu OMO d yz d yz (" 3 -methallyl)(pr 3 )Ti 2 Strong interaction between and Ti centers Tsutsumi,.; Sunada, Y.; Shiota, Y.; Yoshizawa, K.; agashima,. Organometallics 2009, 28, 1988.
19 Catalytic Reactivity of tal-tal Bond Complexes B A 1 mol% Ti cat 2.2 eq amine min, 25 C B A R 2 Ti OTf P P tbu tbu Bimetallic Ti exhibits enhanced catalytic reactivity towards allylic amination Et Et Ti cat (dppe)(! 3 -allyl) (P 3 ) 2 (! 3 -allyl) >99% yield, 1 min 45% yield, 6 h >99% yield, 1 min Ti cat (dppe)(! 3 -allyl) >99% yield, 20 min <5% yield, 24 h (P 3 ) 2 (! 3 -allyl) trace yield, 24 h Walker, W. K.; Kay, B. M.; Ess, D..; Michaelis, D. J. et al J. Am. Chem. Soc. 2015, 137, Walker, W. K.; Anderson, D. L.; Stokes, R. W.; Smith, S. J.; Michaelis, D. J. Org. Lett. 2015, 17, 752.
20 Catalytic Reactivity of tal-tal Bond Complexes B A 1 mol% Ti cat 2.2 eq amine min, 25 C B A R 2 Ti OTf P P tbu tbu Bimetallic Ti exhibits enhanced catalytic reactivity towards allylic amination Et i-pr i-pr Cy Et i-pr t-bu Cy >99% yield 72% yield 98% yield >99% yield t-bu i-pr Cy TMS TMS >99% yield <5% yield 82% yield >99% yield Walker, W. K.; Kay, B. M.; Ess, D..; Michaelis, D. J. et al J. Am. Chem. Soc. 2015, 137, Walker, W. K.; Anderson, D. L.; Stokes, R. W.; Smith, S. J.; Michaelis, D. J. Org. Lett. 2015, 17, 752.
21 Catalytic Reactivity of tal-tal Bond Complexes R 2 Outersphere Reductive Addition Ti P P tbu tbu 15.8 R 2 Ti P P tbu tbu Ti bond: 2.88 Å Ti P P tbu tbu Walker, W. K.; Kay, B. M.; Ess, D..; Michaelis, D. J. et al J. Am. Chem. Soc. 2015, 137, 7371.
22 Catalytic Reactivity of tal-tal Bond Complexes Outersphere Reductive Addition Ti P P tbu tbu R 2 DFT Calculated TS with Ti bond: 2.77 Å Ti P P tbu tbu Ti bond: 2.88 Å strong Ti stabilizing interaction through TS [-C 2 ] P P tbu tbu 5 mol% [] 10 eq Et 2 Et 2 Similar P--P bite angle Boat conformation (X-ray) G = 23.8 kcal/mol (DFT) [-Ti] catalyst [-C 2 ] catalyst >99% yield, 1 min 51% yield, 3 h Walker, W. K.; Kay, B. M.; Ess, D..; Michaelis, D. J. et al J. Am. Chem. Soc. 2015, 137, 7371.
23 Catalytic Reactivity of tal-tal Bond Complexes nitial discovery of stoichiometric C- Borylation (artwig, 1995) solvent catb h! cannot be turned over Bcat + e - -1/2 2 OC O C C O Fp 2 - catalyst decomposition Catalytic C- borylation via - cooperative catalysis (Mankad, 2013) (Pr) + KCp() 2 (Pr)-Fp (10 mol%) Bcat R pinb, h! (ipr) 2 solvent 71% yield (ipr) 2 chanism features a bimetallic oxidative addition and a bimetallic reductive elimination (Pr)-Fp Mazzacano, T. J.; Mankad,. P. J. Am. Chem. Soc. 2013, 135, Waltz, K. M.; e, X.; Muhoro, C.; artwig, J. F. J. Am. Chem. Soc. 1995, 117,
24 Catalytic Reactivity of tal-tal Bond Complexes nitial discovery of stoichiometric C- Borylation (artwig, 1995) solvent catb h! cannot be turned over Bcat + e - -1/2 2 OC O C C O Fp 2 - catalyst decomposition Catalytic C- borylation via - cooperative catalysis (Mankad, 2013) (Pr)-Fp (10 mol%) Bpin R pinb, h! solvent 71% yield chanism features a bimetallic oxidative addition and a bimetallic reductive elimination (Pr)-Fp Mazzacano, T. J.; Mankad,. P. J. Am. Chem. Soc. 2013, 135, Waltz, K. M.; e, X.; Muhoro, C.; artwig, J. F. J. Am. Chem. Soc. 1995, 117,
25 Catalytic Reactivity of tal-tal Bond Complexes Bimetallic Reductive Elimination (ipr) 2 B Bimetallic Oxidative Addition (ipr) BPin Borylation Catalytic Cycle (ipr) 2 (ipr) 2 pinb (ipr) 2 (ipr) 2 h! borylated product Bpin arene C Mazzacano, T. J.; Mankad,. P. J. Am. Chem. Soc. 2013, 135,
26 Catalytic Reactivity of tal-tal Bond Complexes 6 B Bimetallic Oxidative Addition O B O O O B h! C borylation pinb 1 TS TS O B O O O B O B O Energetically feasible concerted process could not be located Parmelee, S. R.; Mazzacano, T. J.; Zhu, Y.; Mankad,. P.; Keith, J. A. ACS. Catat. 2015, 5, 3689.
27 Catalytic Reactivity of tal-tal Bond Complexes h! 5 C borylation Bimetallic Reductive Elimination TS Regeneration of active catalyst via bimetallic R.E. was confirmed experimentally (ipr) 2 (ipr) 2 (ipr) 2 (ipr) 2 (ipr) 2 + (ipr) Parmelee, S. R.; Mazzacano, T. J.; Zhu, Y.; Mankad,. P.; Keith, J. A. ACS. Catat. 2015, 5, 3689.
Reductive Elimination from High-Valent Palladium. Kazunori Nagao MacMillan Group Meeting
Reductive Elimination from igh-valent Palladium Kazunori agao MacMillan Group eting Why do people focus on rging with C activation Facile reductive elimination DG C palladacycle oxidant complex C etero
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,
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
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,
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
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
Formation and Reactivity of Nitrenes with Silver Catalysts for C-H H Bond Amination. Joseph Scanlon Ripon College
Formation and Reactivity of Nitrenes with Silver Catalysts for C-H H Bond Amination Prasoon Saurabh, Kelcey Anderson, Joseph Scanlon Ripon College Why we want C-N C N bonds More chemically reactive than
Title. Author(s)Ishiyama, Tatsuo; Oohashi, Zengo; Ahiko, Taka-aki; M. CitationChemistry Letters, 8: Issue Date Doc URL.
Title Nucleophilic Borylation of Benzyl Halides with Bis(p Author(s)Ishiyama, Tatsuo; Oohashi, Zengo; Ahiko, Taka-aki; M CitationChemistry Letters, 8: 7-781 Issue Date 2002-08-05 Doc URL http://hdl.handle.net/2115/56196
Scission of Dinitrogen by a Molybdenum(III) Xylidene Complex. CHM 5.33 Fall 2005
Scission of Dinitrogen by a Molybdenum(III) Xylidene Complex CHM 5.33 Fall 2005 Introduction The experiment is based on research performed in the laboratory of Professor Cummins during the early 90 s.
Organometallic Chemistry
Organometallic Chemistry Organometallic compounds combine an organic moiety with a metal in a molecule that has direct metal-carbon bonds. Ferrocene, first prepared in 1951, ushered in the modern era of
Rachel Whittaker Dong Group Literature Talk October 10, Ref: Perez-Temprano, M.H, Casares, J.A., Espinet, P., Chem. Eur. J. 2012, 18, 1864.
Rachel Whittaker Dong Group Literature Talk October 10, 2013 Ref: Perez-Temprano, M.H, Casares, J.A., Espinet, P., Chem. Eur. J. 2012, 18, 1864. Overview Introduction Group Exchange C-C Bond Forming Reactions
Nickel-Catalyzed Reductive Cross-Electrophile-Coupling Between Aryl and Alkyl Halides
ickel-catalyzed Reductive Cross-Electrophile-Coupling Between Aryl and Alkyl Halides Eunjae Shim Zakarian Group Literature Talk / Dec 13 th, 2018 University of California, Santa Barbara Table of Contents
Direct Catalytic Cross-Coupling of Organolithium
Literature report Direct Catalytic Cross-Coupling of Organolithium Compounds Reporter: Zhang-Pei Chen Checker: Mu-Wang Chen Date: 02/07/2013 Feringa, B.L.et al. Feringa, B. L. et al. Nature Chem. 2013,
Zr-Catalyzed Carbometallation
-Catalyzed Carbometallation C C C C ML n C C ML n ML n C C C C ML n ML n C C ML n Wipf Group esearch Topic Seminar Juan Arredondo November 13, 2004 Juan Arredondo @ Wipf Group 1 11/14/2004 Carbometallation
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
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
Hybridization of Nickel Catalysis and Photoredox Catalysis. Literature seminar#1 B4 Hiromu Fuse 2017/02/04(Sat)
Hybridization of Nickel Catalysis and Photoredox Catalysis Literature seminar#1 B4 Hiromu Fuse 2017/02/04(Sat) Introduction Novel cross coupling was reported! Highly selective sp 3 C-H functionalization!
Functionalization of C O Bonds. Stefan McCarver. MacMillan Lab Group Meeting
Functionalization of C Bonds Stefan McCarver MacMillan Lab Group eting November 23 rd, 2016 Functionalization of C Bonds "X" X homolytic cleavage catalyst M oxidative addition Why is C Bond Manipulation
Nucleophilic Heterocyclic Carbene Catalysis. Nathan Werner Denmark Group Meeting September 22 th, 2009
Nucleophilic Heterocyclic Carbene Catalysis Nathan Werner Denmark Group Meeting September 22 th, 2009 Thiamine Thiamine Vitamin B 1 The first water-soluble vitamin described Is naturally synthesized by
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
Sharareh Bagherzadeh and Neal P. Mankad* Department of Chemistry, University of Illinois at Chicago, Chicago, IL *
Catalyst Control of Selectivity in CO 2 Reduction Using a Tunable Heterobimetallic Effect Sharareh Bagherzadeh and Neal P. Mankad* Department of Chemistry, University of Illinois at Chicago, Chicago, IL
both substrate : activated wastes derived from M and X one substrate : activated wastes derived from X
October 20th, 2007 Lit. Seminar Transition Metal Catalyzed Intermolecular ormations of - Bond : post-cross Coupling i) Cross Coupling reaction -M + '- -' (M = Zn, Sn, B,,,) ii) Direct ylation - + '- -'
Catalytic alkylation of remote C H bonds enabled by proton-coupled electron transfer
Catalytic alkylation of remote C bonds enabled by proton-coupled electron transfer Reporter: Ji Zhou Checker: Shubo u Date: 2016/11/14 Choi, G. J.; Zhu, Q.-L.; Miller, D. C.; Gu, C. J.; Knowles, R. R.
Supporting Information
Supporting Information Formation of Ruthenium Carbenes by gem-hydrogen Transfer to Internal Alkynes: Implications for Alkyne trans-hydrogenation Markus Leutzsch, Larry M. Wolf, Puneet Gupta, Michael Fuchs,
Organometallic Chemistry and Homogeneous Catalysis
Organometallic Chemistry and Homogeneous Catalysis Dr. Alexey Zazybin Lecture N1 Kashiwa Campus, October 9, 2009 What compounds we can call organometallic compounds? Compounds containing direct metal-carbon
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
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
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,
R 2 R 4 Ln catalyst. This manuscript describes the methods for the synthesis and application of group 4 metallocene bis(trimethylsilyl)acetylene
VII Abstracts 2011 p1 2.12.15 rganometallic Complexes of Scandium, Yttrium, and the Lanthanides P. Dissanayake, D. J. Averill, and M. J. Allen This manuscript is an update to the existing Science of Synthesis
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 )
Nucleophilic Fluorination. Souvik Rakshit Burke group Literature Seminar July 13, 2013
Nucleophilic Fluorination Souvik Rakshit Burke group Literature Seminar July 13, 2013 Relevance 20% of pharmaceuticals contain fluorine 5-fluorouracil Antineoplastic agent, 1957 Lipitor (Atorvastatin)
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 +
A Highly Active Palladium(I) Dimer for Pharmaceutical Applications
DI: 10.1595/147106709472147 A Highly Active alladium(i) Dimer for harmaceutical Applications [d(µ-)( t Bu 3)] 2 AS A ACTICAL CSS-CULIG CATALYST By Thomas J. Colacot Johnson Matthey, Catalysis and Chiral
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
O H Hydrogen bonding promotes H-atom transfer from C H bonds for C-alkylation of alcohols
ydrogen bonding promotes -atom transfer from C bonds for C-alkylation of alcohols Jenna L. Jeffrey, Jack A. Terrett, David W. C. MacMillan Science 2015, 349, 1532-1536 Raffaele Colombo 9/26/2015 Raffaele
Basics of Catalysis and Kinetics
Basics of Catalysis and Kinetics Nobel laureates in catalysis: Haber (1918) Ziegler and Natta (1963) Wilkinson, Fischer (1973) Knowles, Noyori, Sharpless (2001) Grubbs, Schrock, Chauvin (2006) Ertl (2007)
C H activation of aliphatic amines without unnecessary mask M2 Takaya Togo
C H activation of aliphatic amines without unnecessary mask 2017.11.25 M2 Takaya Togo 1 Outline 1.Introduction 2.Free amines as DG Discovery of new activation mode Mechanistic studies Application of the
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
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
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
Cobalt in Organic Synthesis
balt in rganic Synthesis 2 C 2 C C 2 2 C C + C 2 C 2 P Vitamin B 12 Tao Wang MacMillan Lab Group eting ovember 29, 2017 Background Facts about cobalt 27 balt 58.9332 Cl 2 6 2 Electron configuration [Ar]
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
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
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
Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes
![Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes](/thumbs/77/74720708.jpg "Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes")
Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes Selective Synthesis of Multisubstituted Cycloheptadienes 1 2 Cat. Ni 0 1 2 Komagawa, S.; Saito, S. Angew.
"-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,
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
Oxidative Addition/Reductive Elimination 1. Oxidative Addition
Oxidative Addition Oxidative Addition/Reductive Elimination 1 An oxidative addition reaction is one in which (usually) a neutral ligand adds to a metal center and in doing so oxidizes the metal, typically
A Stille or Suzuki reaction is a good choice for this coupling O O because they are functional group tolerant, no radical chemistry F
Chemistry 253 roblem et 3 Due: Friday, ctober 15th ame TF 1. For the following products of cross coupling reactions and indicated bond disconnections, please indicate a reasonable cross coupling protocol
Ligand Effects in Nickel Catalysis. Anthony S. Grillo Chem 535 Seminar October 22, 2012
Ligand in Nickel Catalysis Anthony S. Grillo Chem 535 Seminar October 22, 2012 Transition Metals in Chemistry Organotransition Metal Chemistry, Hartwig, J. F. University Science Books: Mill Valley, CA,
Chiral Bronsted Acids as Catalysts
Chiral Bronsted Acids as Catalysts Short Literature Seminar 6/3/08 Dustin aup BIL Derived osphoric Acids - First reported in 1992 as a ligand by irrung and coworkers. 4 h 2 irrung Tet. Lett. 1992, 33,
Sonogashira Couplings of Aryl Bromides: Room Temperature, Water Only, No Copper
Sonogashira Couplings of Aryl omides: Room Temperature, Water nly, o Copper uce. Lipshutz, David W. Chung, and ian Rich rg.lett. ASAP Article Presentation By ora Jameson Current Lit 08/30/2008 ora Jameson
Recapping where we are so far
Recapping where we are so far Valence bond constructions, valence, valence electron counting, formal charges, etc Equivalent neutral classification and MLX plots Basic concepts for mechanism and kinetics
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.
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
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
Recent Advances of Alkyne Metathesis. Group Meeting Timothy Chang
Recent Advances of Alkyne Metathesis Group Meeting Timothy Chang 11-09-10 Fischer Carbyne and Schrock Alkylidyne Fischer Doublet LX type 4e Schrock Quartet X 3 type 6e -1-3 lone pair covalent p-back bonding
Reactivity within Confined Nano-spaces
Reactivity within Confined Nano-spaces Larry Wolf Group Meeting 11-17-09 Encapsulating Cyclobutadiene hemicarcerand Anslyn, E. V; Dougherty, D. A. Modern Physical Organic Chemistry Cram. D. J. et. al.
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.
Nature of the Chemical Bond with applications to catalysis, materials science, nanotechnology, surface science, bioinorganic chemistry, and energy
Lecture 13, October 31, 2016 Transition metals, Pd and Pt Nature of the Chemical Bond with applications to catalysis, materials science, nanotechnology, surface science, bioinorganic chemistry, and energy
Investigation of the Role and Form. Formation. Michael Enright
Investigation of the Role and Form of Silver Catalysts in C N Bond Formation Michael Enright Ripon College Importance Carbon Nitrogen Bonds Medicine Biological compounds Make C N bonds whenever we want
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
Organocopper Reagents
rganocopper eagents General Information!!! why organocopper reagents? - Efficient method of C-C bond formation - Cu less electropositive than Li or Mg, so -Cu bond less polarized - consequences: 1. how
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
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
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,
A Summary of Organometallic Chemistry
A Summary of Organometallic Chemistry Counting valence electrons (v.e.) with the ionic model 1. Look at the total charge of the complex Ph 3 P Cl Rh Ph 3 P PPh 3 OC CO 2 Fe OC CO Co + charge:0 charge:
Paper No and Title. Module No and Title CHEMISTRY
1 Subject Paper No and Title Module No and Title Module Tag Chemistry 11, Inorganic Chemistry III (Metal π-complexes and Metal Module 33: Preparation, structure and bonding of compounds CHE_P11_M33 2 TABLE
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
Selectivity in Non-Directed C H Functionalization of sp 3 C H Bonds
Selectivity in on-directed C Functionalization of sp 3 C Bonds aromatic C primary C benzylic C Ac secondary C α-heteroatom C tertiary C gan Shaw MacMillan Group eting C Functionalization: Challenges for
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...
Bifunctional Asymmetric Catalysts: Design and Applications. Junqi Li CHEM Sep 2010
Bifunctional Asymmetric Catalysts: Design and Applications Junqi Li CHEM 535 27 Sep 2010 Enzyme Catalysis vs Small-Molecule Catalysis Bronsted acid Lewis acid Lewis acid Bronsted base Activation of both
C H Bond Functionalization: New Strategies for the Synthesis of Complex Natural Products and Pharmaceuticals. Phil Knutson Ferreira Group 12/3/2015
C H Bond Functionalization: New Strategies for the Synthesis of Complex Natural Products and Pharmaceuticals Phil Knutson Ferreira Group 12/3/2015 New strategies in organic synthesis nsf-cchf.com What
Iron Catalyzed Cross Coupling: Mechanism and Application. Matthew Burk Denmark Group Meeting
Iron Catalyzed Cross Coupling: Mechanism and Application Matthew Burk Denmark Group Meeting 3-10-2009 Long Induction Period: Early History Of Iron Catalyzed Cross Coupling 1941: Effect of metal impurities
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
Palladium-catalyzed sp 3 C H activation. Yan Xu Dong Group Meeting Apr. 2, 2014
Palladium-catalyzed sp 3 C H activation, Yan Xu Dong Group Meeting Apr. 2, 2014 Content 1 Allylic C H activation 2 Benzylic C H activation Palladiumcatalyzed sp 3 C H activation 3 4 Common sp 3 C H activation:
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
Supplementary Figures
Supplementary Figures Supplementary Figure 1. DFT optimized structure of the [Ag III (L 1 )](ClO 4 ) 2 (1 ClO4 ) complex (CCDC code 978368). Hydrogen atoms and the two perchlorate anions have been omitted
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
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,
Organic Chemistry Laboratory Summer Lecture 6 Transition metal organometallic chemistry and catalysis July
344 Organic Chemistry Laboratory Summer 2013 Lecture 6 Transition metal organometallic chemistry and catalysis July 30 2013 Summary of Grignard lecture Organometallic chemistry - the chemistry of compounds
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,
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
Heidelberg Molecular Modelling Summer School The Challenges of Transition Metal Systems
Heidelberg Molecular Modelling Summer School The Challenges of Transition Metal Systems Dr Rob Deeth Inorganic Computational Chemistry Group University of Warwick UK verview Is molecular modelling of TM
Carbonyl Ylide Cycloadditions
Carbonyl Ylide Cycloadditions cond. icholas Anderson Denmark Group eting 07/13/10 Carbonyl Ylides Uncharged 1,3-Dipole Conjugated π-system ighly reactive on-isolable Generate in-situ Carbonyl Ylide Stability
Enantioselective Borylations. David Kornfilt Denmark Group Meeting Sept. 14 th 2010
Enantioselective Borylations David Kornfilt Denmark Group Meeting Sept. 14 th 2010 30.000-foot View Enantioenriched Organoboranes What to do with them Crudden C. M. et. al., Eur. J. Org. Chem. 2003, 46
CEM 852 Exam LDA, THF, 0 C, 15 min; then
CEM 85 Exam- April, 005 This exam consists of 5 pages. Please write ALL your answers in the answer books. Please write legibly and draw all structures clearly. Good luck. 1. Provide examples of the following
Lecture 16 February 20 Transition metals, Pd and Pt
Lecture 16 February 20 Transition metals, Pd and Pt Nature of the Chemical Bond with applications to catalysis, materials science, nanotechnology, surface science, bioinorganic chemistry, and energy Course
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
Transition Metal-Catalyzed Carbon-Carbon Bond Cleavage (C-C Activation) Group Meeting Timothy Chang
Transition Metal-Catalyzed Carbon-Carbon Bond Cleavage (C-C Activation) Group Meeting 01-15-2008 Timothy Chang Outlines - Fundamental considerations, C-H versus C-C activation - Orbital interactions -
Homogeneous Gold Catalysis - Unique Reactivity for Activation of C C Multiple Bonds
1 rganic Seminar 2011.05.09 omogeneous Gold Catalysis - Unique Reactivity for Activation of C C Multiple Bonds ysical rganic Chemistry Laboratory (Nakamura Laboratory) D2 Masaki Sekine Development of Gold
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
Chem 634. Introduction to Transition Metal Catalysis. Reading: Heg Ch 1 2 CS-B 7.1, , 11.3 Grossman Ch 6
Chem 634 Introduction to Transition etal Catalysis eading: eg Ch 1 2 CS-B 7.1, 8.2 8.3, 11.3 Grossman Ch 6 Announcements Problem Set 1 due Thurs, 9/24 at beginning of class ffice our: Wed, 10:30-12, 220
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
Enantioselective 1,1-Arylborylation of. Transfer with Pd Catalysis
Enantioselective 1,1-Arylborylation of Alkenes: Merging Chiral Anion Phase Transfer with Pd Catalysis Reporter: Lian-Jin Liu Checker: Wen-Xue Huang Date: 12/05/2015 F. Dean Toste University of California,
OC 2 (FS 2013) Lecture 3 Prof. Bode. Redox Neutral Reactions and Rearrangements
C 2 (F 203) Lecture 3 Prof. Bode edox eutral eactions and earrangements Types of edox eutral rganic eactions. eactions with no external reducing or oxidizing agent In this case, one part of the starting
Problem 1 (4 points) D2h. C2v. Part A.
Problem 1 (4 points) In 2004, a bimetallic Zr compound exhibiting side-on N2 binding was reported by Chirik and coworkers (Nature, 2004, 427, pp. 527-530). The crystal structure of this compound was obtained,
A Highly Efficient Organocatalyst for Direct Aldol Reactions of Ketones and Aldehydes
A ighly Efficient rganocatalyst for Direct Aldol Reactions of Ketones and Aldehydes Zhuo Tang, Zhi-ua Yang, Xiao-ua Chen, Lin-Feng Cun, Ai-Qiao Mi, Yao-Zhong Jiang, and Liu-Zhu Gong Contribution from the
I. Liu Lab. Ka<e Boknevitz 1
A ighly Convergent Total Synthesis of Leustroducsin B Barry M. Trost,* Berenger Biannic, Cheyenne S. Brindle, B. Michael Keefe, Thomas J. unger, and Ming-Yu gai Department of Chemistry, Stanford University,
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