Comparative Studies of Cathodically-Promoted and Base-Catalyzed Michael Addition Reactions of Levoglucosenone
作者:Alexander V. Samet、Murat E. Niyazymbetov、Victor V. Semenov、Andrei L. Laikhter、Dennis H. Evans
DOI:10.1021/jo961019g
日期:1996.1.1
Regioselective Michael addition of nitro and heterocyclic compounds to levoglucosenone, 1, is effectively catalyzed by amines and also by cathodic electrolysis. In comparison to the base-catalyzed reaction, it was found that under electrochemical conditions the reaction proceeds under milder conditions and with higher yields. Cathodically-initiated Michael addition of thiols to levoglucosenone using small currents
硝基和杂环化合物向左葡糖醛酮1的区域选择性迈克尔加成反应可通过胺和阴极电解有效地催化。与碱催化的反应相比,发现在电化学条件下反应在较温和的条件下以较高的产率进行。在几种情况下,使用小电流通过阴极引发的迈克尔将硫醇迈克尔加成到左葡萄糖苷中,会产生以前未知的苏式加成产物。当使用大电流时,倾向于形成正常的赤型异构体,即动力学产物。相反,缓慢,低电流的电解促进了这两种形式的平衡,因此赤型可以通过逆向反应和重新沉淀转化为苏式。还报道了将2-萘硫醇加到(R)-(+)-apoverbenone中。