Catalytic asymmetric synthesis of indole-based atropisomers bearing silicon-stereogenic centers

Abstract

The first diastereo- and enantioselective synthesis of indole-based atropisomers bearing Si-stereogenic centers has been established via the strategy of catalytic asymmetric reductive silylation. By this strategy, a wide range of indole-based atropisomers bearing Si-stereogenic centers were synthesized in moderate to good yields with overall excellent enantioselectivities and good diastereoselectivities (up to 87% yield, 94% ee, 7.3 : 1 dr). This work not only provides a new strategy for catalytic asymmetric synthesis of atropisomers bearing Si-stereogenic centers, but also has realized the first catalytic asymmetric synthesis of indole-based atropisomers with a Si-stereogenic center, which will add an important member to the family of indole-based atropisomers bearing multiple chiral elements. Moreover, this work also presents the first catalytic asymmetric reductive silylation of indole scaffolds, which adds new content to enantioselective C–Si bond formation.