Asymmetric Allylic Alkylation and Hydrogenation with Transition Metal Complexes of Diphosphite Ligands Based on (1S,2S)-Trans-1,2-cyclohexanediol
作者:Zengbo Pang、Mi Tian、Haifeng Li、Lailai Wang
DOI:10.1007/s10562-017-1986-8
日期:2017.4
diphosphite ligands, which were derived from (1S,2S)-trans-1,2-cyclohexanediol, have been described. It was found that (1S,2S)-bis[(S)-1,1′-binaphthyl-2,2′-diyl]phosphite-cyclohexanediol was the suitable ligand in the Pd-catalyzed allylic alkylation, and up to 75% ee for (E)-dimethyl 2-(1,3-diphenylallyl)malonate was obtained. In compared with the results of the asymmetric allylic alkylation, (1S,2S)-bis[(R)-1
已经描述了由一系列手性二亚磷酸酯配体组成的新钯配合物的原位制备,这些配体来源于 (1S,2S)-反式-1,2-环己二醇。发现(1S,2S)-双[(S)-1,1'-联萘-2,2'-二基]亚磷酸酯-环己二醇是Pd催化烯丙基烷基化的合适配体,高达75%得到(E)-2-(1,3-二苯基烯丙基)丙二酸二甲酯的ee。与不对称烯丙基烷基化的结果相比,(1S,2S)-双[(R)-1,1'-联萘-2,2'-二基]亚磷酸酯-环己二醇被证明是最有效的配体。 Rh 催化的衣康酸二甲酯和烯酰胺的不对称氢化,ee 高达 99%。二醇骨架和配体的二芳基部分之间的立体化学匹配组合对于在两种转化中诱导高对映选择性是必不可少的。发现产物的对映体区分意义主要由亚磷酸联萘基团的构型决定。