Synthesis of aromatic terminal allenes and aliphatic terminal alkynes from hydrazones using calcium carbide as an acetylene source

Abstract

A simple method for the selective synthesis of aromatic terminal allenes and aliphatic terminal alkynes from the reactions of calcium carbide with aromatic ketone and aldehyde p-tosylhydrazones or aliphatic ketone and aldehyde p-tosylhydrazones using copper as a mediator is described. The salient features of this protocol are the use of a readily available and easy-to-handle acetylene source, operational simplicity, high yield, and broad substrate scope.