energy of CN bond rotation. The intrinsic feature of this Lewis acid activation was found to be the activation of the LUMO, as well as an intermediate‐stabilization effect. The catalytically active species was believed to be a 1:1 complex of phosphoric acid and MgCl2, which was stabilized by a H⋅⋅⋅Cl hydrogen bond. The chiral catalytic complex selectively recognizes and activates one of the two helical
通过使用DFT计算和标记实验对叔
氨基环化反应进行了机理研究。结果表明,反应通过限速,立体定向和表面上的1,5-H-转移途径进行,随后形成无障碍的CC键。由于CN键旋转的激活能量高,因此可以排除面部选择的立体控制模式。发现该
路易斯酸活化的内在特征是LUMO的活化以及中间稳定作用。催化活性物质被认为是
磷酸与MgCl 2的1:1络合物,由H⋅⋅⋅Cl氢键稳定。手性催化络合物选择性地识别并激活底物A的两个螺旋构型之一,这是1,5-超表面H-转移所必需的,这决定了成型产物的立体选择性。