ORGN 386 |
| Recent progress in Lewis acid-Lewis base (LA-LB) bifunctional catalysis has witnessed the development of a new family of tethered LA*-LB* (* denotes chirality) bifunctional catalysts that feature a planar chiral LA* for electrophilic activation and the LB* for asymmetric induction. In contrast to chiral catalysts that rely on the LA* for asymmetric induction, the openly accessible coordination sites of the planar LA* are designed to activate a broader scope of substrates, and most importantly, to abolish its role in determining the stereoselectivity of the reaction. Placing the stereodetermining factor solely on the LB* not only decouples asymmetric induction (i.e., LB*-dependent) from electrophilic activation (i.e., by the LA*), but also renders a predictable chiral induction prior to reaction execution. An empirical model for predicting the R/S absolute configuration in LB*-dependent asymmetric bifunctional catalysis will be presented. |
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Asymmetric Reactions and Syntheses
8:00 AM-12:00 PM, Tuesday, August 21, 2007 BCEC -- 253C, Oral
Division of Organic Chemistry |