Asymmetric Epoxidation Catalyzed by α,α-Dimethylmorpholinone Ketone. Methyl Group Effect on Spiro and Planar Transition States
作者:O. Andrea Wong、Bin Wang、Mei-Xin Zhao、Yian Shi
DOI:10.1021/jo900739q
日期:2009.8.21
Asymmetric epoxidation of olefins by using an alpha,alpha-dimethylmorpholinone-containing chiral ketone catalyst (4) has been investigated. This ketone, which has the combined features of several previously studied catalysts, is an effective catalyst for trans- and trisubstituted olefins, and up to 97% ee has been achieved. The alpha,alpha-dimethyl group has significant impact oil spiro and planar transition states.