Intramolecular cyclization of benzyl-substituted cyclopentadienyl titanium dichlorides promoted by boron tribromide

Intramolecular cyclization of α,α-alkyl-ortho-methoxybenzylcyclopentadienyl titanium complexes to form titanoxacycle complexes promoted by BBr3 has been studied. A probable two-step mechanism involving halogen exchange and intramolecular elimination was proposed. Four related benzyl-substituted cyclopentadienyl titanium complexes have been studied by X-ray crystallography.