A Dual-Catalysis/Anion-Binding Approach to the Kinetic Resolution of Allylic Amines
摘要:
A dual-catalysis approach enables the small-molecule catalyzed kinetic resolution of allylic amines by acylation. By employing 2 mol % of each 4-(pyrrolidin D)pyridine (PPY) and a readily available chiral hydrogen-bonding cocatalyst, the first nonenzymatic kinetic resolution of allylic amines was accomplished with s factors of up to 20.
Kinetic Resolution of Unsaturated Amides in a Chlorocyclization Reaction: Concomitant Enantiomer Differentiation and Face Selective Alkene Chlorination by a Single Catalyst
作者:Arvind Jaganathan、Richard J. Staples、Babak Borhan
DOI:10.1021/ja407241d
日期:2013.10.2
kinetic resolution via chlorofunctionalization of olefins is reported. The enantiomers of racemic unsaturated amides were found to have different hydrogen-bonding affinities for chiral Lewis bases in numerous solvents. This interaction was exploited in developing a kinetic resolution of racemic unsaturated amides via halocyclization. The same catalyst serves to both "sense chirality" in the substrate
报道了通过烯烃氯官能化进行动力学拆分的第一个例子。发现外消旋不饱和酰胺的对映异构体在多种溶剂中对手性路易斯碱具有不同的氢键亲合力。这种相互作用被用于通过卤环化开发外消旋不饱和酰胺的动力学拆分。相同的催化剂既可以在基材中“感知手性”,又可以将高度选择性的氯传递到烯烃官能团上,从而产生高达 99:1 dr 和高达 98.5:1.5 er 的立体三元组产物。选择性因子通常大于 50,以允许以接近 50% 的产率同时合成高度对映体富集形式的产物和未反应的底物。该反应使用催化量(≤0.