Greener and Expeditious Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Terminal Acetylenes and in situ Generated α-Azido Ketones

Abstract

A convenient and mild protocol for the one-pot regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles in aqueous PEG 400 has been reported. The methodology involves the one-pot reaction of α-bromo ketones, sodium azide, and terminal acetylenes catalyzed by Cu(I) in aqueous PEG 400 at room temperature. Prominent features of our approach are mild reaction conditions, use of readily available α-bromo compounds, aqueous PEG 400 as a benign reaction medium, avoiding the isolation of labile α-azido ketones, simple workup, and good yields.