Copper-catalyzed ortho-alkenylation of quinoline N-oxides with alkynes

Abstract

A copper-catalyzed regioselective C-2 alkenylation of quinoline N-oxides with alkynes and pinacol diborane has been developed. This method provides efficient access to a wide variety of deoxygenated 2-alkenyl quinolines with good functional group tolerance. In particular, highly regio- and stereoselective reactions were observed with unsymmetrical alkynes such as aryl(alkyl)acetylenes and enynes. The reaction involves borylcupration of alkynes, capture of the catalytically generated alkenyl copper species by quinoline N-oxides and deborylation.