3,3‘-Bis(diphenylphosphino)-1,1‘-disubstituted-2,2‘-biindoles: Easily Accessible, Electron-Rich, Chiral Diphosphine Ligands for Homogeneous Enantioselective Hydrogenation of Oxoesters
作者:Tiziana Benincori、Oreste Piccolo、Simona Rizzo、Franco Sannicolò
DOI:10.1021/jo001207d
日期:2000.12.1
Racemic (+/-)-3,3'-bis(diphenylphosphinyl)-1,1'-dimethyl-2, 2'-biindole (1c) (N-Me-2-BINPO) and (+/-)-3, 3'-bis(diphenylphosphinyl)-1,1'-bis(methoxymethyl)-2,2'-biindole (1d) (N-MOM-2-BINPO) were synthesized in satisfactory yields following a three-step reaction sequence, starting from indole. Resolution of racemic 1c and 1d was achieved through fractional crystallization of their diastereomeric adducts
外消旋(+/-)-3,3'-双(二苯基膦基)-1,1'-二甲基-2,2'-联吲哚(1c)(N-Me-2-BINPO)和(+/-)-3 ,按照三步反应顺序,以令人满意的产率合成了3'-双(二苯基膦基)-1,1'-双(甲氧基甲基)-2,2'-联吲哚(1d)(N-MOM-2-BINPO),从吲哚开始。外消旋体1c和1d的拆分是通过将它们的非对映体加合物与旋光二苯甲酰基酒石酸进行分步结晶,然后对非对映体纯盐进行碱性分解而实现的。它们的三氯硅烷还原得到对映体纯的膦(+)-和(-)-(1a)(N-Me-2-BINP)和(+)-和(-)-(1b)(N-MOM-2-BINP)。发现1a和1b的电化学氧化电势分别为0. 52和0.60V。(1a)的两种对映体均在α-和β-氧代酯的不对称氢化反应中作为Ru(II)的配体进行测试。发现反应非常快并且对映体很好。以1a,1c,BINAP和其他双杂芳族二膦作为Ru(