Highly diastereoselective cascade dearomatization of 3-(2-isocyanoethyl)indoles with nitrile imines: a facile access to unexpected polycyclic indolines

Abstract

A highly efficient dearomatization of 3-(2-isocyanoethyl)indoles with in situ generated nitrile imines has been developed through a nucleophilic/Friedel–Crafts/aza-Mannich type cascade and 1,3-dipolar cycloaddition reaction under catalyst-free and mild reaction conditions. This strategy offers a novel and convenient route to the rapid assembly of a wide range of unprecedented polycyclic indoline scaffolds in moderate to excellent yields and diastereoselectivities.