Transition-metal-free oxidative annulation reactions between N-acyl-2-aminoacetophenones and alkynes for the facile synthesis of 2-amino-1-naphthols

Abstract

A novel method for the regioselective synthesis of 2-amino-1-naphthols through cascade oxidative annulation of N-acyl-2-aminoacetophenones and alkynes has been successfully developed. This protocol uses no metal catalysts and could be performed with easily available substrates in a single step. The method exhibits broad substrate scope with good functional group compatibility and is amenable for late-stage functionalization of natural compounds and biologically relevant motifs. Mechanistic studies indicated that the additive lithium chloride was effective in the stabilization of persistent C-radical intermediates from N-acyl-2-aminoacetophenone.