Synthesis of Axially and Centrally Chiral N‐Alkenyl Indoles by Asymmetric Rh‐Catalyzed [2 + 2 + 2] Cycloaddition

Abstract

Axially chiral indoline‐based scaffolds are virtually universal in biological and pharmaceutical compounds. In this study, we demonstrate the Rh‐catalyzed asymmetric [2 + 2 + 2] cycloaddition of 1,6‐enynes with steric hindered N‐alkynyl indoles, which enables simultaneous construction of both axial and central chirality, containing a quaternary carbon center, in one step. Notable features of these reactions include excellent chemo‐, regio‐, diastereo‐ and enantioselectivity, 100% atom‐economy, easily available SEGPHOS ligand, and mild conditions.