Anchimeric assistance by the methoxy group in solvolysis of the compounds (Me3Si)2C(SiMe2OMe)(SiMe2X)
作者:Colin Eaborn、M. Novella Romanelli
DOI:10.1039/p29870000657
日期:——
solvolysis of the compounds (Me3Si)2C(SiMe2OMe)(SiMe2X)(1), it has been shown that the reaction of (1;X= Cl) with MeOH–dioxane is (a) little accelerated by NaOMe and (b) markedly slower than that with CF3CH2OH–dioxane; these results confirm that the much greater reactivity of (1; X= Cl) than of (Me3Si)3CSiMe2Cl in such solvolyses arises from anchimeric assistance by the γ-OMe group to the rate-determining
在对化合物(Me 3 Si)2 C(SiMe 2 OMe)(SiMe 2 X)(1)的溶剂化研究中,表明(1 ; X = Cl)与MeOH–二恶烷的反应为(a)NaOMe几乎没有促进作用,并且(b)显着低于CF 3 CH 2 OH-二恶烷的作用;这些结果证实了(1 ; X = Cl)的反应性比(Me 3 Si)3 CSiMe 2更大。CL在这样solvolyses源于由γ-OME组Cl组成的速率决定离开邻位协助-和形成阳离子中间体。在用MeOH或MeOH二恶烷(化合物的反应的顺序反应1)似乎是(X =)溴> NO 3 > 0 3 SC 6 H ^ 4 ME- p >氯,SCN> 0 2 CCF 3 > NCS> O 2 CPh,O 2 CMe> F,N 3,H。对于X = Br,O 2 CMe和O 2 CPh,在这些情况下以及对于X = O 2 CCF 3,观察到自催化。证明了HX催化。在