Mapping the Active Site in a Chemzyme: Diversity in the N-Substituent in the Catalytic Asymmetric Aziridination of Imines
摘要:
The active site of the aziridination catalyst derived from either the VANOL or VAPOL ligand and B(OPh)(3) is larger than expected and can accommodate not only significant substitution on the diarylmethyl unit of the imine but also that alkyl (but not perfluorylalkyl) substituents on the aryl groups lead to enhanced rates and enantioselection. The screen of diarylmethyl N-substituents on the imine revealed that the 3,5-di-tert-butyldianisylmethyl group (BUDAM) gave exceptionally high asymmetric inductions for imines of aryl aldehydes.
Mapping the Active Site in a Chemzyme: Diversity in the <i>N</i>-Substituent in the Catalytic Asymmetric Aziridination of Imines
作者:Yu Zhang、Zhenjie Lu、Aman Desai、William D. Wulff
DOI:10.1021/ol802431v
日期:2008.12.4
The active site of the aziridination catalyst derived from either the VANOL or VAPOL ligand and B(OPh)(3) is larger than expected and can accommodate not only significant substitution on the diarylmethyl unit of the imine but also that alkyl (but not perfluorylalkyl) substituents on the aryl groups lead to enhanced rates and enantioselection. The screen of diarylmethyl N-substituents on the imine revealed that the 3,5-di-tert-butyldianisylmethyl group (BUDAM) gave exceptionally high asymmetric inductions for imines of aryl aldehydes.
Controlled Diastereo- and Enantioselection in a Catalytic Asymmetric Aziridination
作者:Aman A. Desai、William D. Wulff
DOI:10.1021/ja1038648
日期:2010.9.29
the development of an unprecedented universal catalyticasymmetricaziridination protocol. The substrate scope is broad and includes iminespreparedfrom both electron-rich and electron-poor aromatic aldehydes and also from 1°, 2°, and 3° aliphatic aldehydes. The face selectivity of the addition to the imine was found to be independent of the diazo compounds. The (S)-VANOL or (S)-VAPOL derived catalyst