Construction of benzimidazole- and indole-fused azabicyclo[3.1.0]hexanes bearing a cyano-containing quaternary center from vinylsulfonium salts through sequential [3 + 2]/[2 + 1] cyclization†

Abstract

A sequential [3 + 2]/[2 + 1] annulation reactions of benzimidazole- and indole-derived acrylonitriles with vinylsulfonium salts have been developed for the first time, and shown to provide in yields of 32 to 98% a series of azabicyclo[3.1.0]hexanes containing each a cyano-substituted tetrasubstituted carbon stereocenter with >20 : 1 dr. This method features simplicity, high efficiency and broad substrate scopes. Moreover, the synthetic utility was demonstrated with gram-scale reactions and further transformations of the products.