Substrate-controlled divergent synthesis of polycyclic indoloazepines and indolodiazepines via 1,5-hydride shift/7-cyclization cascades

Abstract

Novel and practical acid-catalyzed cyclization of 2-indolyl aryl carbinols via tandem dehydration/1,5-hydride shift/7-cyclization sequences has been developed. By appropriate variation of the substrate, diverse polycyclic-fused indoles were synthesized in good yield, thus demonstrating the high efficiency, transition-metal-free nature, and high step/atom economy of the synthesis strategy.