Alkylation of α,α-dichloroarylmethane with trialkylboranes: Synthesis of alkylarylcarbinols
作者:George W. Kabalka、Nan-Sheng Li、Su Yu
DOI:10.1016/0040-4039(95)01870-n
日期:1995.11
The alkylation of α,α-dichloroarylmethane with trialkylboranes occurs readily in the presence of t-butyllithium at −78 °C. The reaction affords the corresponding alkylarylcarbinols in good yields after oxidation with sodium perborate.
Retentive solvolysis. Part 14. The methanol-perturbed phenolysis of optically active 2,2-dimethyl-1-(p-methoxyphenyl)propyl p-nitrobenzoate. The mechanism and the structure of the second ion-pair intermediate
The polarimetric and titrimetricrate constants have been measured for the solvolysis of optically active 2,2-dimethyl-1-(p-methoxyphenyl)propyl p-nitrobenzoate (ROPNB) in phenol–methanol (97:3 w/w). The salt effect of added (Bun)4NClO4 indicates that all products are derived from the second ion-pair intermediate (Int-2), not from the first (Int-1), as for the phenolysis in pure phenol. Competitive
旋光和滴定速率常数已经在酚-甲醇(97:3 w / w)中对旋光性2,2-二甲基-1-(对甲氧基苯基)丙基对硝基苯甲酸酯(ROPNB)的溶剂化进行了测量。添加的(Bu n)4 NClO 4的盐效应表明,就纯苯酚中的酚解而言,所有产物均来自第二离子对中间体(Int-2),而不是来自第一离子对中间体(Int-1)。竞争性溶剂分解,即甲醇干扰的酚醛分解,产生了部分倒置的ROPh,o-和p -RC 6 H 4OH和部分保留的ROMe,而在纯苯酚中进行酚解则得到部分保留的ROPh和o-和p -RC 6 H 4 OH。该立体化学结果表明,Int-2(这些酚类酶的关键中间体)具有从背面被酚分子屏蔽的离子对结构。确定了所有产品的绝对配置和最大旋转。
Fischer,A. et al., Journal of the Chemical Society, 1963, p. 751 - 753