Mechanistic and synthetic studies in catalytic allylic alkylation with palladium complexes of 1-(2-diphenylphosphino-1-naphthyl)isoquinoline
作者:John M. Brown、David I. Hulmes、Patrick J. Guiry
DOI:10.1016/s0040-4020(01)89381-9
日期:1994.4
correlation between catalyst and reactant was in the opposite sense. Many of the trends can be satisfactorily rationalised by recourse to the NMR spectra of a series of Pd allyl complexes. In the case of the (E,E)-1,3-diphenylallyl complex, two diastereomers were observed and their configurations assigned with the aid of nOe experiments. The results are best interpreted if the reaction proceeds through a late
标题配合物是用于(E)-1,3-二苯基-2-乙酸丙烯酯和丙二酸二甲酯离子之间反应的高反应性催化剂;优选地,该配合物是乙酸根。对映体过量取决于反应的进行方式,在67%到98%之间变化,在CH 3中获得最佳结果在15冠-5的存在下于−13°C的CN。用乙酸2-环己烯酯,反应要慢得多,并且获得的最佳ee是67%。与1,1,3-三苯基-2-丙烯基乙酸酯相比,反应再次慢于第一种情况,最佳ee为47%,催化剂和反应物之间的构型相关性却相反。通过使用一系列Pd烯丙基配合物的NMR光谱,可以令人满意地合理化许多趋势。在(E,E)-1,3-二苯基烯丙基配合物的情况下,观察到两个非对映异构体,并借助nOe实验确定了它们的构型。如果反应通过晚期过渡态进行,并且对烯丙基的反式至配体的磷以及优先在主要的非对映异构体上进行亲核攻击,则可以最好地解释结果。