作者:Ben-Ami Feit、Sarit Shapira、Amatzya Herbst
DOI:10.1016/0040-4020(94)00949-u
日期:1995.1
A novel reaction - a β-elimination of a hydride ion from carbanion salts RM (R = Li, MgBr) and R2N−Li+, and its transfer to tetra-substituted activated olefins of the type Ar2C=C(CN)CO2R (R=Me,Et), was studied. Yields of the reduced H−-acceptor were used to follow the extent of the H−-transfer reaction. A competing Michael addition reaction of RM to the activated olefin also took place. The effects
一种新的反应-从碳负离子盐RM(R = Li,MgBr)和R 2 N - Li +中消除氢离子,并将其转移到Ar 2 C = C(CN)型四取代的活化烯烃中研究了)CO 2 R(R = Me,Et)。减小的H的产量-端受体被用来按照H的程度- -转移反应。RM与活化烯烃的竞争性迈克尔加成反应也发生了。溶剂,反应温度,正抗衡离子和的,将H的各种结构特征的溶剂化性能的影响-端供体和H --受体,进行了研究。由于反应的双分子性,与两种反应物有关的结构因素起着至关重要的作用。在RM,次甲基型β碳,或RM的R的小尺寸的Çβ甲苄基取代基,导致在H的相对高的程度- -转移反应。这表明,目前研究的氢离子的β-消除作用是通过双分子E 2 cB型机制产生的。