Synthesis of alleneferrocenes through CuI-mediated Crabbé homologation reaction

Abstract

A concise and efficient method for the synthesis of bifunctional allene ferrocenes based on the modified Crabbé homologation reaction of ferrocenylacetylenes with paraformaldehyde promoted by CuI was developed. The presented synthesis proceeded readily with high compatibility of sensitive functional groups on the cyclopentadiene ring providing good to excellent yields of the desired products.