ORGN 57 |
| Introducing asymmetry into organic structures represents a continuing contemporary challenge of particular importance for biologically important molecular targets. Rationally devising catalytic systems to achieve such a result is a most significant goal. Asymmetric reactions involving transition metal catalysis have focused exclusively on reactions 1) in which the enantiodiscriminating event of forming or breaking a bond occurs within the coordination sphere of the metal and, thereby, proximal to the asymmetric inducing groups and 2) in which only one type of bond is formed, i.e., C-H, C-O, or C-C. Catalytic allylic alkylations differ in both respects. Bond breakage or formation occurs outside the coordination sphere of the metal and, therefore, distal to any enantiodiscriminating groups. In addition, many different types of bonds can be formed—C-C, C-N, C-S, C-O, C-H etc. Efforts to define the requirements for asymmetric transition metal complexes that can effect such reactions generally, the types of catalytic processes in which asymmetry can be introduced, and the applicability of these catalytic processes will be outlined. Emphasis will be placed upon inducing stereochemistry by the most difficult mechanism – at the nucleophile! The utility of this methodology for developing synthetic strategy to biologically significant targets will be highlighted. |
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H. C. Brown Legacy Symposium
1:30 PM-5:00 PM, Sunday, 10 September 2006 Moscone Center -- Room 134, Oral
Division of Organic Chemistry |