Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA.
Science. 2009 Dec 18;326(5960):1662. doi: 10.1126/science.1180739.
Kinetic resolution of strained three-membered rings has proven broadly useful for the generation of enantiopure organic intermediates. Herein we demonstrate a complementary approach whereby a single catalyst transforms a racemic mixture of aziridines to a pair of regioisomeric products, each in good yield with exceptionally high enantioselectivity. Specifically, the dimeric yttrium salen catalyst accelerates the ring opening of aliphatic aziridines by trimethylsilylazide, inducing nucleophilic attack at the primary position of one enantiomer and the secondary position of the other. Both rate and selectivity are highly sensitive to the catalyst structure.
动力学拆分环状三员环已被证明是一种广泛适用于生成手性纯有机中间体的方法。在这里，我们展示了一种互补的方法，即单一催化剂将外消旋混合物的氮丙啶转化为一对区域异构体产物，每种产物的产率都很好，对映选择性极高。具体来说，二聚钇席夫碱催化剂通过三甲基硅基叠氮化物加速脂肪族氮丙啶的开环，诱导亲核进攻一种对映体的一级位置和另一种对映体的二级位置。速率和选择性都对催化剂结构高度敏感。
