Copper(I)‐Mediated Oxidative Cross‐Coupling between Functionalized Alkynyl Lithium and Aryl Magnesium Reagents

Abstract

All crossed: The reaction of unsaturated copper reagents with various alkynyl lithium compounds provides mixed lithium cuprates, which in the presence of chloranil undergo an oxidative coupling, thus leading to polyfunctional alkynes or enynes. Bromoenynes prepared by this method are readily converted into pyridine derivatives by a new ring closure that proceeds at low temperature (see scheme, tol=tolyl).