a mechanism favoring initial rate-determining step of ionization of the carbon-halogen bond in which the migrating group plays a minor role, if any, followed by migration of a silyl group from silicon to carbon. Disilanes (I) and (II) enter into the Friedel-Crafts reaction with benzene to give, after methylation, PhCH2SiMe2SiMe3 and Ph2CHSiMe2SiMe3, respectively.
四种新的(
氯甲基)乙
硅烷(ClCH 2)Cl 2 SiSiCl 2 Me(I),(Cl 2 CH)Cl 2 SiSiCl 2 Me(II),(ClCH 2)MeClSiSiClMe 2(III)和(ClCH 2)Me 2制备并研究了SiClCl 3(IV)对
氯化铝分子内重排的态度。反应性按以下顺序降低:(III)>(IV)>(II)⪢(I)。与Me 3 SiSiMe 2(CH 2 Br)(V),ClMe 2 SiSiMe 2(CH 2发现在
溴化铝存在下,Br)(VI)和Me 3 SiSiMeCl(CH 2 Br)(VII)的降低顺序为:(V)>(VI)>(VII)。根据有利于碳-卤素键的电离的初始速率确定步骤的机理来讨论结果,其中迁移基团起着很小的作用,如果有的话,然后是甲
硅烷基团从
硅迁移到碳。乙
硅烷(I)和(II)与苯进入弗瑞德-克来福特反应,甲基化后分别得到PhCH 2 SiMe 2 SiMe