Stable Optically Pure Phosphino(silyl)carbenes: Reagents for Highly Enantioselective Cyclopropanation Reactions
作者:Jerzy Krysiak、Céline Lyon、Antoine Baceiredo、Heinz Gornitzka、Marian Mikolajczyk、Guy Bertrand
DOI:10.1002/chem.200305722
日期:2004.4.19
trans-N,N'-diisopropylcyclohexane-1,2-diamine and N,N'-diisopropyl-1,2-ethanediamine, are not observed; instead the 1,3-diphosphete 4 and a novel six-membered heterocycle 8, which results from the dimerization of 3 and the reaction of 7 with its diazo precursor 6, respectively, have been isolated. In contrast, the phosphino(silyl)carbene 14 derived from N,N'-di-tert-butyl-1,2-ethanediamine has been isolated
在磷上带有环状二氨基取代基的膦基(三甲基甲硅烷基)卡宾的稳定性在很大程度上取决于氮取代基的空间位阻。未观察到衍生自反式-N,N'-二异丙基环己烷-1,2-二胺和N,N'-二异丙基-1,2-乙二胺的膦碳卡宾3和7;取而代之的是,分别分离了分别由3的二聚化和7与重氮前体6的反应产生的1,3-二磷酸4和一个新颖的六元杂环8。相反,已经高产率地分离了衍生自N,N′-二叔丁基-1,2-乙二胺的膦基(甲硅烷基)卡宾14。通过使用对映体纯的(S,S)-和(R,R)-N,N'-二叔丁基-1,2-二苯基-1,2-乙二胺,第一个光学上纯的膦基(甲硅烷基)制备了卡宾苯(S,S)-17和(R,R)-17。