Asymmetric alkenylation reaction of benzoxazinones with diarylethylenes catalyzed by B(C6F5)3/chiral phosphoric acid

Abstract

Catalytic enantioselective alkenylation is an efficient method to construct chiral alkene molecules, but the asymmetric alkenylation of simple alkenes catalyzed by metal-free catalysts remains an elusive challenge. Herein, we reported an asymmetric alkenylation of benzoxazinones with diarylethylenes by utilizing a B(C6F5)3/chiral phosphoric acid catalyst. A broad of benzoxazinones and diarylethylenes with electron-withdrawing and electron-donating groups were tolerated (up to 95% yield and 97.5:2.5 e.r.) in the methodology under mild reaction conditions. Moreover, the synthetic utility was confirmed by the scaled-up reaction and transformations of the products. The mechanism was preliminarily explored by control reactions, nonlinear effect experiment and DFT calculations.