中文摘要：

本文总结了常用亲核试剂对非对称环氧乙烷的亲核开环反应及其区域选择性。强亲核性的亲核试剂通常只受空间效应影响,进攻非对称环氧乙烷位阻小的碳原子,对于烯基取代环氧乙烷还可以进攻烯基的β-碳原子发生SN2′开环反应,其他亲核试剂同时受空间效应和电子效应的影响,对于烷基环氧乙烷通常进攻其取代少的碳原子,空间效应起主导作用,而对芳基和烯基取代环氧乙烷开环反应通常发生在环氧乙烷芳甲位和烯丙位的碳原子上,电子效应起主导作用。在质子酸或强Lewis酸存在下,虽然单烷基环氧乙烷的开环仍然发生在其取代少的碳原子上,但对于芳基、烯基和同碳双取代环氧乙烷,亲核开环反应将主要受电子效应控制,一般亲核试剂倾向于进攻环氧乙烷的芳甲位、烯丙位或多取代的碳原子。分子内的亲核开环反应主要受成环时环大小的控制,成环时的倾向是五元环〉六元环〉七元环。环氧乙烷亲核开环的区域选择性是环氧乙烷和亲核试剂空间效应和电子效应平衡的结果。

英文摘要：

Nucleophilic ring opening reactions of unsymmetric oxiranes and their regioselectivity with widely used nucleophiles are reviewed.Strong nucleophiles attack the less substituted carbon atom of unsymmetric oxiranes,whatever alkyl,alkenyl,and aryloxiranes,controlled by the steric hindrance only.They can undergo an SN2′ ring-opening reaction with alkenyloxiranes via the attack on the β-carbon atom of their alkenyl group.Other nucleophiles generally attack the less substituted carbon atom for alkyloxiranes,controlled by the steric hindrance,but attack the arylmethyl and allyl carbon atom for aryl and alkenyloxiranes,controlled by the electronic effect.In the presence of proton acids or strong Lewis acids,although monoalkyloxiranes are attacked on their less substituted carbon atom with nucleophiles（steric hindrance control）,aryl,alkenyl,and geminal dialkyloxiranes are attacked on their more substituted carbon atom with weak nucleophiles（electronic effect control）.The regioselectivity of intramolecular nucleophilic ring opening reaction of oxiranes is controlled by the ring size of products.The favorable order is five-membered ring six-membered ring seven-membered ring.Thus,the regioselectivity is controlled by a balance between the steric hindrance and electronic effect of oxiranes and nucleophiles.