Reaction of trimethylaluminium with main group hydroxides: a non-hydrolysis route to methylalumoxane†
作者:Stephen J. Obrey、Andrew R. Barron
DOI:10.1039/b104578b
日期:——
Reaction of AlMe3 with [(tBu)2Ga(μ-OH)]3 or Ph3EOH (E = Sn, Pb) yields catalytically active MAO, [MeAlO]n, along with (tBu)2GaMe and Ph3EMe, respectively, in contrast, the reaction with Ph3EOH (E = C, Si, Ge) yields [Me2Al(μ-OEPh3)]2; the formation of MAO is proposed to occur via hydroxide exchange and the formation of unstable [Me2Al(μ-OH)]n; the propensity towards alkane elimination versus hydroxide exchange is controlled by the relative Brønsted acidity of the main group hydroxide.
三甲基铝(AlMe3)与[(tBu)2Ga(μ-OH)]3或Ph3EOH(E = Sn, Pb)反应分别生成具有催化活性的MAO、[MeAlO]n,以及(tBu)2GaMe和Ph3EMe;相比之下,与Ph3EOH(E = C, Si, Ge)反应则生成[Me2Al(μ-OEPh3)]2。据推测,MAO的形成是通过羟基交换和生成不稳定的[Me2Al(μ-OH)]n实现的;烷烃消除倾向与羟基交换倾向的差异受主族羟基相对布伦斯特酸性控制。