Synthesis of titanium alkoxide complexes with alkyl lactate ligands. Asymmetric epoxidation of cinnamyl alcohol

A family of titanium (IV) alkoxide compounds [{Ti(OPri)3(OLact)}2], and [Ti(OPri)2(OLact)2] (1–6) have been prepared by alcohol exchange of Ti(OPri)4 and the corresponding alkyl-2-hydroxy-alkylpropionate or alkyl lactate (LactOH = Benzyl-(S)-lactate, methyl-(S)-3-phenyllactate and menthyl-(S)-lactate. These alkoxide titanium (IV) compounds have been characterized by spectroscopic and electrochemical techniques. In addition, these chiral Lewis acid titanium compounds have been studied in the asymmetric epoxidation of cynnamyl alcohol, the obtained results show that these complexes with dynamic behaviour in solution exert low control of the enantioselectivity. Electronic and sterical effects of the ligands in the catalytic results have been studied.