Aryloxide-Facilitated Catalyst Turnover in Enantioselective α,β-Unsaturated Acyl Ammonium Catalysis
作者:Anastassia Matviitsuk、Mark D. Greenhalgh、Diego-Javier Barrios Antúnez、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/anie.201706402
日期:2017.9.25
β-unsaturated p-nitrophenyl ester substrate to facilitate catalyst turnover. This method was used for the enantioselective isothiourea-catalyzed Michael addition of nitroalkanes to α,β-unsaturated p-nitrophenyl esters in generally good yield and with excellent enantioselectivity (27 examples, up to 79 % yield, 99:1 er). Mechanistic studies identified rapid and reversible catalyst acylation by the α,β-unsaturated
报道了一种新的 α,β-不饱和酰基铵催化的通用概念,该概念使用 α,β-不饱和对硝基苯酯底物释放对硝基苯酚来促进催化剂周转。该方法用于对映选择性异硫脲催化的硝基烷烃与 α,β-不饱和对硝基苯基酯的迈克尔加成反应,收率普遍良好,对映选择性极佳(27 个实例,收率高达 79%,99:1 er)。机理研究确定了 α,β-不饱和对硝基苯酯的快速和可逆催化剂酰化,并且最近报道的可变时间归一化动力学分析方法用于描述复杂的反应动力学。