Nguyen Hiep N, Hultzsch Kai C
Department of Chemistry and Chemical Biology Rutgers, The State University of New Jersey 610 Taylor Road 8087 Piscataway, New Jersey 08854- USA.
Universität Wien Fakultät für Chemie Institut für Chemische Katalyse Währinger Straße 38 1090 Wien Austria.
European J Org Chem. 2019 Apr 24;2019(15):2592-2601. doi: 10.1002/ejoc.201900107. Epub 2019 Mar 13.
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 with resolution factors reaching as high as 90(5) for hex-5-en-2-amine (). Kinetic analysis of the enantioenriched substrates with the matching and mismatching catalyst revealed that the efficiency of catalyst benefits significantly from a favorable Curtin-Hammett pre-equilibrium and by a large ratio. Other binaphtholate catalysts were less efficient due to a less favorable Curtin-Hammett pre-equilibrium, which often favored the mismatching substrate-catalyst combination. Cyclization of the matched substrate proceeds generally with large -selectivity, whereas the -ratio for mismatched substrates is significantly diminished, favoring the -cyclization product isomer in some instances.
使用各种3,3'-硅基取代的联萘酚钇催化剂研究了通过分子内氢胺化对α-取代氨基戊烯的动力学拆分。利用环己基二苯基硅基取代的催化剂，对于甲基、苄基和苯基取代的底物，在动力学拆分中观察到了高效率，对于己-5-烯-2-胺，拆分因子高达90(5)。用匹配和不匹配的催化剂对对映体富集的底物进行动力学分析表明，催化剂的效率显著受益于有利的柯廷-哈米特预平衡和较大的比例。其他联萘酚催化剂效率较低，因为柯廷-哈米特预平衡不太有利，这通常有利于不匹配的底物-催化剂组合。匹配底物的环化通常以较大的选择性进行，而不匹配底物的比例显著降低，在某些情况下有利于环化产物异构体。
