Highly efficient copper-catalyzed synthesis of internal alkynes via aerobic oxidative arylation of terminal alkynes

Abstract

We have developed a novel and highly efficient, copper-catalyzed synthesis of internal alkynes via oxidative couplings of aromatic boronic acids with terminal alkynes at room temperature. The protocol uses inexpensive copper(I) oxide [Cu2O] as the catalyst, oxygen in the air as the stoichiometric oxidant; no ligand and sealed reaction vessels are required, and remarkable functional group tolerability is observed with coupling occurring. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.