Monocyclopentadienyltitanium Aryloxide Complexes:  Preparation, Characterization, and Application in Cyclization Reactions

Abstract

A variety of monocyclopentadienyltitanium aryloxide complexes were prepared, characterized by X-ray crystallography, and used to catalyze or mediate cyclization reactions. Structural characterization allowed for the comparison of steric parameters of various 2,6-disubstituted aryloxide ligands. Transformations of dienes and enynesincluding the catalysis of a 1,6-diene cycloisomerization and the intramolecular Pauson−Khand reactionwere investigated. A titanium metallacycle was prepared from a sterically hindered enyne containing a trisubstituted olefin. The Pauson−Khand reaction of trimethylsilyl-substituted enynes was promoted to generate α-silylcyclopentenones