系列讲座之十七(Albert S. C. Chan).ppt

Recent Progress on Catalytic Asymmetric Synthesis Albert S. C. Chan The Hong Kong Polytechnic University Our book published in 2000! The catalytic asymmetric hydrogenation is a great success both in scientific discovery and in commercial application. An important challenge for organic chemists is to make catalytic asymmetric formation of C-C, C-O, C-N bonds equally successful. Synthesis of Ferrocene-based P/S Mixed-donor Ligands and Their Application in Asymmetric Allylic Substitution Introduction Preparation of Chiral Ugi amine Asymmetric Hydrogenation of Prochiral Acetyl Ferrocene Synthetic Approach A brief highlight on new ligand scaffold…. A new class of highly “fine-tunable” chiral ferrocene-based N-P/S mixed-donor ligands prepared. Thioether (SR) group Phosphinyl (PR’2) group Amino (NR’’) group Applications: P/S ligands Asymmetric Allylic Alkylation (C-C Bond formation) Scope of Substrate: evaluation of amine Asymmetric Allylic Etherification (C-O Bond Formation) The Scope of Substrates (Alcohols) The Scope of Substrates (Con’t.) Asymmetric homogeneous Rh-catalyzed Pauson-Khand-type reaction in alcoholic solvents 3 mol% Rh, 6 mol% L, 1.5 eq. of cinnamyaldehyde Ir-catalyzed asymmetric Pauson-Khand reaction Application of chiral iridium catalyst for asymmetric Pauson-Khand-type cyclization Ir-catalyzed asymmetric Pauson-Khand reaction The highest ee achieved so far. Reaction conditions: 5 mol% [Ir(COD)Cl]2, (Ir:BINAP = 1:1), enyne (0.3 mmol), aldehyde (1.5 mmol) and anhydrous dioxane (4.0 mL) were stirred at 100-105 ?C for 48 h under nitrogen atmosphere Lam, W. S.; Kok, S. H. L.; Au-Yeung, T. T.-L.; Wu, J.; Cheung, H. Y.; Lam, F. L.; Yeung, C. H.; Chan, A. S. C. Adv. Synth. Catal. 2006 348, 370. Gokel, G.; Hoffmann, P.; Klusacek, H.; Marquarding, D.; Ruch, E.; Ugi, I. Angew. Chem. Int. Ed. Engl. 1970, 9, 64. R 92 99 14 PhMe (0.5) Zn(OAc)2 7 R 86 99 14 CH3CN (0.5) Zn(OAc)2 6 R 89 99 14 CH2Cl2 (0.5) Zn(OAc)2 5 R 90 99 14 THF (0.5) Zn(OAc)2 4 R 8