Mechanistic Studies of Catalytic Olefin Dimerization Reactions Using Electrophilic η<sup>3</sup>-Allyl−Palladium(II) Complexes
作者:Geraldine M. DiRenzo、Peter. S. White、Maurice Brookhart
DOI:10.1021/ja9602354
日期:1996.1.1
The dimerization of olefins by well-defined cationic η3-allyl−palladium complexes of the type [(C3H5)Pd(L)(PR3)]+[BAr‘4]- (Ar‘ = [3,5-C6H3(CF3)2]; L = OEt2, H2O; R = cyclohexyl (Cy), n-butyl (nBu)) has been studied. These complexes react with ethylene or methyl acrylate at −80 °C with loss of L to form the η2-olefin complexes [(C3H5)Pd(η2-olefin)(PR3)]+[BAr‘4]- (olefin = H2CCH2, CH2CHC(O)OCH3). Upon
烯烃通过明确定义的 [(C3H5)Pd(L)(PR3)]+[BAr'4]- (Ar' = [3,5-C6H3(CF3)] 类型的阳离子 η3-烯丙基-钯配合物进行二聚2]; L = OEt2, H2O; R = 环己基 (Cy), 正丁基 (nBu)) 已被研究。这些配合物在 -80 °C 下与乙烯或丙烯酸甲酯反应,失去 L,形成 η2-烯烃配合物 [(C3H5)Pd(η2-烯烃)(PR3)]+[BAr'4]-(烯烃 = H2CCH2, CH2CHC(O)OCH3)。加热后,烯丙基-烯烃偶联发生。乙烯的二聚反应在 0 °C 下迅速发生,带有可观察到的乙基-乙烯中间体 [(C2H5)Pd(C2H4)2(PCy3)]+[BAr'4]-。丙烯酸甲酯反应形成稳定的丙烯酸酯螯合物,[(CH3O(O)CCH2CH2)Pd(CH2CHC(O)OCH3)(PR3)]+[BAr'4]-,这是丙烯酸甲酯二聚的