A simple cobalt catalyst system for the efficient and regioselective cyclotrimerisation of alkynes

Chem Commun (Camb). 2005 Mar 21:(11):1474-5. doi: 10.1039/b417832g. Epub 2005 Jan 26.

Abstract

The intermolecular cyclotrimerisation of terminal and internal alkynes can be catalysed by simple cobalt complexes such as a CoBr2(diimine) under mild reaction conditions when treated with zinc and zinc iodide with high regioselectivity in excellent yields.