Sulfinimines of trifluoropyruvate: Novel intermediates for chiral non racemic α-trifluoromethyl α-amino acids
作者:Pierfrancesco Bravo、Marcello Crucianelli、Barbara Vergani、Matteo Zanda
DOI:10.1016/s0040-4039(98)01698-0
日期:1998.10
Key-building blocks are the sulfinimines (S)-1a,b, prepared via Staudinger reaction from trifluoropyruvic esters and the chiral N-sulfinyl iminophosphorane (S)-5, which were reacted with benzyl and alkylmagnesium halides. The resulting N-sulfinyl α-Tfm α-amino esters 6a,b and 6c-g, respectively, were produced with opposite stereoselectivity. The stereocontrol with alkyl Grignard reagents was progressively
提出了一种合成非外消旋的α-三氟甲基(Tfm)α-氨基酸(AAs)的新方法,并且对制备有用。关键的结构单元是亚磺胺(S)-1a,b,它是通过Staudinger反应由三氟丙酮酸酯和手性N-亚磺酰基亚氨基膦酸酯(S)-5制备的,它们与苄基卤化物和烷基镁卤化物反应。分别以相反的立体选择性产生所得的N-亚磺酰基α-Tfmα-氨基酯6a,b和6c-g。烷基格氏试剂的立体控制随着空间体积的增加而逐渐提高。一些加合物6分别转化为α-Tfm-苯丙氨酸(R)-8(可再生并回收手性助剂),α-Tfm-亮氨酸(S)-11e,α-Tfm-丁氨酸(S)-11f和α-Tfm-丙氨酸(S)-11g分两步放在一个锅中。SCV1