Polymerization of ε-caprolactone using bulky alkoxo-titanium complexes and structural analysis of [Ti(OBorneoxo)2Cl2(thf)2]

A variety of bisalkoxo titanium dichloride THF adducts [Ti(OR)2Cl2(thf)2] {OR = adamantanoxo (9), (1R,2S,5R)-(−)-menthoxo (10), (1S-endo)-(−)-borneoxo (11)} have been prepared and characterized by spectroscopic techniques. The molecular structure of 11 has been determined by single-crystal X-ray diffraction studies. The parent Lewis acid bisalkoxo titanium dichloride derivatives and related alkoxo complexes [Ti(OR)2(OPri)2]2 have been tested as initiators in ring-opening polymerization of ε-caprolactone and l-lactide.