Enantioselective Epoxidation of Nonconjugated <i>cis</i>-Olefins by Chiral Dioxirane
作者:Christopher P. Burke、Yian Shi
DOI:10.1021/ol901724v
日期:2009.11.19
A variety of nonconjugated cis-olefins has been enantioselectively epoxidized with chiral ketones 2, and up to 92% ee has been obtained. The two prochiral faces of an olefin are likely stereodifferentiated by the relative hydrophobicity of the olefin substituents and/or allylic oxygen functionality.
A simple catalytic system consisting of PdCl2 and N,N-dimethylacetamide enabled clean and selective synthesis of ketones from internal olefins using molecular oxygen. Various functionalized internal olefins were directly and regioselectively oxidized; C atoms of CC bonds far from substituted moieties were preferably oxidized.