Novel supramolecular organocatalysts of hydroxyprolinamide based on calix[4]arene scaffold for the enantioselective Biginelli reaction
作者:ZhengYi Li、HuaiJie Xing、GuoLi Huang、XiaoQiang Sun、JuLi Jiang、LeYong Wang
DOI:10.1007/s11426-011-4374-z
日期:2011.11
A series of novel supramolecular organocatalysts of hydroxyprolinamide based on the upper rim of calix[4]arene scaffold have been developed to catalyze enantioselective multi-component Biginelli reaction. Under the optimal conditions, the reactions occurred with moderate-to-excellent enantioselectivities (up to 98% ee). A plausible transition state constructed by the supramolecular interaction of hydrogen bond and cation-π between catalysts and substrates has been proposed.
Highly enantioselective Biginelli reaction catalyzed by a simple chiral primary amine catalyst: asymmetric synthesis of dihydropyrimidines
作者:Da-Zhen Xu、Hui Li、Yongmei Wang
DOI:10.1016/j.tet.2012.07.027
日期:2012.9
Several chiral primary amines were introduced as organocatalysts for the asymmetric Biginellireaction. The reaction was performed by using a combined catalyst consisting of a chiral bifunctional primary amine–pyridine 5j and hydrochloric acid in a mixed solvent of 1,4-dioxane/CHCl3 (8/2, v/v) at room temperature. The corresponding dihydropyrimidines were obtained in moderate to high yields with up