手性Ti(Ⅳ)/聚合物催化二乙基锌对醛的不对称加成反应

Asymmetric Addition of Diethyl Zinc to Aldehyde Catalyzed by Chiral Ti(Ⅳ)/Schiff Base Polymer

设计合成了新型的 Schiff碱类手性聚合物 ,该聚合物与 Ti(O-i-Pr) 4“原位”配合得到的 Ti( ) /poly-mer催化剂应用于催化二乙基锌对芳香醛的不对称加成反应中 ,得到较高的化学产率和光学收率 ,e.e.值高达 84 .5% .考察了反应温度、底物结构等因素对对映选择性的影响 。

New Schiff base chiral polymers was synthesized. The asymmetric addition of diethyl zinc to aldehyde was achieved catalyzed by Ti(Ⅳ)/polymer which was formed in situ from chiral polymer and \{Ti(O i Pr) 4.\} Optical alcohols were obtained in a high yield with e.e. up to 84.5%. The effects of temperature, complex time, structure of substrate etc. on the catalytic activity and enantio selectivity were studied in detail. The reaction mechanism was proposed.