Rare‐Earth‐Metal‐Catalyzed Kinetic Resolution of Chiral Aminoalkenes via Hydroamination: The Effect of the Silyl Substituent of the Binaphtholate Ligand on Resolution Efficiency
作者:Hiep N. Nguyen、Kai C. Hultzsch
DOI:10.1002/ejoc.201900107
日期:2019.4.24
The kinetic resolution of α‐substituted aminopentenes via intramolecular hydroamination was investigated using various 3,3′‐silyl‐substituted binaphtholate yttrium catalysts. High efficiencies in the kinetic resolution were observed for methyl‐, benzyl‐, and phenyl‐substituted substrates utilizing the cyclohexyldiphenylsilyl‐substituted catalyst 2c with resolution factors reaching as high as 90(5)
使用各种 3,3'-甲硅烷基取代的联萘酸钇催化剂研究了通过分子内加氢胺化作用对 α-取代氨基戊烯的动力学拆分。使用环己基二苯基甲硅烷基取代的催化剂 2c 观察到甲基、苄基和苯基取代的底物的动力学拆分效率很高,对 hex-5-en-2-amine (3a) 的拆分因子高达 90(5) )。具有匹配和错配催化剂的对映体富集底物的动力学分析表明,催化剂 2c 的效率显着受益于有利的 Curtin-Hammett 预平衡和较大的 kfast/kslow 比。其他联萘酚催化剂效率较低,因为 Curtin-Hammett 预平衡不太有利,这通常有利于错配的底物-催化剂组合。