Zirconium-promoted intramolecular cyclization of terminal alkynes and unusual carbonylation reaction

Abstract

N-(2-bromoallyl)-N-prop-2-ynyl- and N-allyl-N-(2-bromoallyl)-amines 1 and 5 undergo intramolecular cyclization by sing zirconocene methyl chloride to give zirconacycles 4 and 6, respectively, which are characterized by deuteriolysis affording products 2 and 7; carbonylation of 6 and further reaction with electrophiles (deuterium oxide, allyl bromide, 4-chlorobenzonitrile, benzaldehyde, benzophenone and benzylideneaniline) leads to compounds 8, 9 and 11–15.