Catalytic asymmetric cyanosilylation of ketones, aldehydes, thioketones, thioaldehydes, imines and hydrazones
申请人:——
公开号:US20030236226A1
公开(公告)日:2003-12-25
One aspect of the present invention relates to a method for the catalytic asymmetric cyanosilylation of ketones, aldehydes, thioketones, thioaldehydes, imines and hydrazones. The critical elements of the method are: a non-racemic chiral tertiary-amine-containing catalyst; a substrate selected from the group consisting of ketones, aldehydes, thioketones, thioaldehydes, imines and hydrazones; and a silyl cyanide, e.g., trimethylsilyl cyanide. In preferred embodiments, the substrate is a ketone or aldehyde. A preferred embodiment of the present invention relates to practicing the method in a halocarbon solvent, e.g., chloroform. Another preferred embodiment of the present invention relates to practicing the method in an ester solvent, e.g., ethyl acetate. In certain embodiments, the methods of the present invention produce a silyl cyanohydrin with an enantiomeric excess greater than about 80%. In certain embodiments, the methods of the present invention produce a silyl cyanohydrin with an enantiomeric excess greater than about 90%.
本发明的一个方面涉及一种用于催化不对称氰硅化酮、醛、硫代酮、硫代醛、亚胺和肼酮的方法。该方法的关键要素包括:非外消旋手性三级胺含量的催化剂;从酮、醛、硫代酮、硫代醛、亚胺和肼酮组成的底物;以及硅基氰化物,例如三甲基硅基氰化物。在优选实施例中,底物为酮或醛。本发明的一个优选实施例涉及在卤代碳溶剂中(例如氯仿)实施该方法。本发明的另一个优选实施例涉及在酯溶剂中(例如乙酸乙酯)实施该方法。在某些实施例中,本发明的方法产生旋光异构体过量大约高于80%的硅基氰水合物。在某些实施例中,本发明的方法产生旋光异构体过量大约高于90%的硅基氰水合物。