The effect of substituents in SRNl reactions. Some synthetic applications
作者:Joseph F. Bunnett、Eric Mitchel、Carlo Galli
DOI:10.1016/s0040-4020(01)97188-1
日期:1985.1
Most of the ortho effects are slight, but there is evidence that large ortho substituents hinder attachment of the phosphite more than the enolate nucleophile. The methoxy and diethoxyphosphoryl substituents, when para to the site of substitution, respectively favour and disfavour the phosphite with respect to the enolate ion. SRNl reactions of ortho-substituted halobenzenes are, for some substituents
几个邻位取代的iodobenzenes被允许反应,经由S RN升机构,用亚磷酸二乙酯和离子烯醇频哪酮离子的混合物。从产物组成数据,推算出两种亲核试剂的相对反应性。它们代表与芳基自由基中间体连接的相对反应性。大多数邻位作用是轻微的,但是有证据表明,较大的邻位取代基比亚油酸酯亲核试剂更阻碍亚磷酸酯的附着。当在取代位置的对位时,甲氧基和二乙氧基磷酰基取代基相对于烯醇酸根离子分别有利和不利于亚磷酸酯。小号RN对于某些取代基,邻位取代的卤代苯的反应是随后进行的其他反应,这些反应提供了具有合成意义的产物。