Chiral Brønsted acid-catalyzed conjugate addition of indoles to azadienes: Enantioselective synthesis of hetero-triarylmethanes

An efficient chiral Brønsted acid-catalyzed conjugate addition of indoles to azadienes has been successfully developed, which enables a facile approach to optically active hetero-triarylmethanes with excellent enantioselectivities and broad substrate scope. This chiral Brønsted acid catalytic system provides a new opportunity for the development of asymmetric reactions of azadienes.