Influence of aluminum Lewis acids on the diastereoselectivity of the nickel-catalyzed [2+2+2] cycloaddition of norbornadiene and electron deficient alkenes
作者:Olivier Pardigon、Alphonse Tenaglia、Gérard Buono
DOI:10.1016/s0040-4039(00)00545-1
日期:2000.5
The stereoselective formation of 8-substituted deltacyclanes by homo Diels–Alder (HDA) reaction using a phosphine modified nickel catalyst generated by reduction of Ni(acac)2 with alkylaluminums is discussed. Depending on the nature of the alkene and on the nickel catalytic system, fair to excellent exo selectivity are observed. A switch in selectivity favoring the endo-cycloadduct is observed when
讨论了使用膦改性的镍催化剂,通过用烷基铝还原Ni(acac)2生成的膦改性镍催化剂,通过均质Diels-Alder(HDA)反应形成8位取代的环戊烷的立体选择。取决于烯烃的性质和镍催化体系,观察到相当至优异的异位选择性。在选择性有利于开关内时取代的烯烃的极性甲氧基羰基与铝物质活化-cycloadduct观察。