Ruthenium-catalyzed carbon-carbon bond formation between propargylic alcohols and alkenes via the allenylidene-ene reaction

J Am Chem Soc. 2003 May 21;125(20):6060-1. doi: 10.1021/ja035106j.

Abstract

A novel ruthenium-catalyzed carbon-carbon bond formation between propargylic alcohols and alkenes via the allenylidene-ene reaction has been found to afford the corresponding 2,4-disubstituted-1-hexen-5-ynes in moderate yields. The finding described here discloses a new reactivity of allenylidene complexes. As a synthetic application, intramolecular cyclization of propargylic alcohols bearing an alkene moiety has been developed to give the corresponding syn-substituted chromanes in high yields with an excellent diastereoselectivity.