Asymmetric aldol reactions of trifluoromethyl ketones with a chiral Ni(II) complex of glycine: Stereocontrolling effect of the trifluoromethyl group
作者:Vadim A Soloshonok、Dimitry V Avilov、Valery P Kukhar
DOI:10.1016/0040-4020(96)00741-7
日期:1996.9
Asymmetric aldol reactions between trifluoromethyl ketones and a Ni(II) complex of the Schiff base of glycine with (S)-o-[N-(N-benzylprolyl)amino]benzophenone (BPB) have been studied. Sterically demanding aryl and sec-alkyl trifluoromethyl ketones, and highly enolizable benzyl trifluoromethyl ketone failed to react with the Ni(II) complex, while n-alkyl and acetylenyl trifluoromethyl ketones reacted
三氟甲基酮和镍(II)复合物中的的之间是不对称羟醛缩合反应希夫甘氨酸的碱与(小号- )ö - [ ñ - (Ñ -benzylprolyl)氨基]苯甲酮(BPB)进行了研究。立体要求高的芳基和仲烷基三氟甲基酮,以及高度可烯化的苄基三氟甲基酮无法与Ni(II)配合物反应,而正烷基和乙炔基三氟甲基酮则易于反应,并能获得高产率的醛醇(56-87%)非对映异构体过量较高的产品(90–98%)。分解生成的络合物可得到非对映体和对映体纯的(2 S,3 S)-3-具有生物医学意义的-3-三氟甲基-3-取代的丝氨酸。讨论了解释所观察到的非对映选择性的机械工作模型。