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。