酸度效应:确定了p K a与催化活性和立体选择性之间的相关性,并在meta ‐中的p K a -log(k)和p K a -log(R / S)相关性中观察到线性自由能关系(LFER)。和/或对位取代的芳族硫脲(见图)。这些结果为新催化剂的开发提供了基础,并且在我们最初的尝试中发现了几种改进的催化剂。
Solvent-free enantioselective conjugate addition and bioactivities of nitromethane to Chalcone containing pyridine
作者:Guoping Zhang、Chun Zhu、Dengyue Liu、Jianke Pan、Jian Zhang、Deyu Hu、Baoan Song
DOI:10.1016/j.tet.2016.11.063
日期:2017.1
catalysts in the enantioselective Michael additions of nitromethane to α,β-unsaturated ketones containing pyridine. The best results were obtained with the bifunctional catalyst prepared from 3,5-di(trifluoromethyl)-aniline under solvent-free conditions. This thiourea promoted the reaction with high enantioselectivities and chemical yields for aryl ketones. The origins of enantioselectivity were further