A catalytic asymmetric Friedel-Crafts alkylation of N-aryl anilines with aurone-derived azadienes for the first synthesis of benzofuran and N-aryl aniline containing triarylmethanes has been developed.

Abstract

Herein, we disclose a catalytic asymmetric Friedel-Crafts alkylation of N-aryl anilines with aurone-derived azadienes for the first synthesis of benzofuran and N-aryl aniline containing triarylmethanes. An easily available chiral phosphoric acid, TRIP, was found to be effective for this reaction. The triarylmethanes with benzofuran and N-aryl aniline motifs were obtained in moderate yields with high regio- and good to high enantioselectivities. The scope of the reaction was broad and few synthetic transformations have been demonstrated.