非支载可回收配体——OsO_4催化烯烃的不对称氨羟化反应

Study on the Asymmetric Aminohydroxylation of Olefins Catalyzed by a Free Recoverable and Reusable Ligand

以N-氯代氨基甲酸苄酯为氧化供氮试剂，在V（正丙醇）：V（水）=1：1均相体系中，用一种可回收并能重复使用的非支载配体A催化5种烯烃的不对称氨羟化（AA）反应，表现出较高的催化活性（化学产率为48％～63％，光学产率为84％-98％e．e．）；同时将该配体用于催化苯乙烯的AA反应，可回收和重复使用5次，催化活性及立体选择性没有明显改变。

Excellent enantioselectives of up to 98% e. e. were achieved in the presence of benzyl N-chlorocarbamate as oxidant and nitrogen source when a free recoverable cinchona ligand was used for homogeneous asymmetric aminohydroxylation（AA） of five olefins. In the AA reaction of styrene, this ligand can be easily recovered and reused for five times without any significant loss in its catalytic efficiency.