Enantioselective conjugate addition of aliphatic thiols to divergently activated electron poor alkenes and dienes
作者:Rafał Kowalczyk、Aleksandra J. Wierzba、Przemysław J. Boratyński、Julia Bąkowicz
DOI:10.1016/j.tet.2014.06.035
日期:2014.9
Divergently activated double bonds in electron poor 4-oxo-butenoates and (2E,4E)-6-oxo-2,4-dienoates underwent stereoselective and regioselective addition of mercaptans catalyzed by simple Cinchona alkaloids. Application of quinine and quinidine afforded both enantiomers of the 1,4-adducts with respect to the ketone carbonyl group in ees of up to 80%. Single recrystallization of some adducts resulted
电子贫乏的4-氧代-丁烯酸酯和(2 E,4 E)-6-氧代-2,4-二烯酸酯中的发散活化双键经历了简单的金鸡纳生物碱催化的硫醇的立体选择性和区域选择性加成。相对于酮中的酮羰基,使用奎宁和奎尼丁可得到1,4-加合物的两种对映体,最高可达80%。一些加合物的一次重结晶导致进一步富集高达99%ee。