Denmark Scott E, Chung Won-Jin
Department of Chemistry, Roger Adams Laboratory, University of Illinois, Urbana, Illinois 61801, USA.
J Org Chem. 2006 May 12;71(10):4002-5. doi: 10.1021/jo060153q.
A variety of achiral Lewis bases were found to catalyze the addition of TMSCN to the aldehydes. Among them, phosphines and amines were the most efficient catalysts. In addition, several chiral amines and phosphines were examined in a catalytic, asymmetric addition of TMSCN to benzaldehyde albeit with low enantioselectivity. A mechanistic study revealed that the reaction was first order in aldehyde, first order in Lewis base, and zeroth order in TMSCN, suggesting the complex formation of TMSCN and Lewis base formation of complex i. However, there are at least two possible scenarios for this catalytic process, and in view of the low selectivities observed, it is not clear which mechanism is operative.
人们发现多种非手性路易斯碱可催化三甲基硅腈（TMSCN）与醛的加成反应。其中，膦和胺是最有效的催化剂。此外，还研究了几种手性胺和膦催化TMSCN与苯甲醛的不对称加成反应，不过对映选择性较低。机理研究表明，该反应对醛为一级反应，对路易斯碱为一级反应，对TMSCN为零级反应，这表明TMSCN与路易斯碱形成了配合物i。然而，该催化过程至少有两种可能的情况，鉴于观察到的选择性较低，尚不清楚哪种机理起作用。
