31024-63-2Relevant articles and documents
Silicon α-effect: A systematic experimental and computational study of the hydrolysis of Cα- and Cγ-functionalized alkoxytriorganylsilanes of the formula type ROSiMe2(CH 2)nX (R = Me, Et; N = 1, 3; X = functional group)
Berkefeld, Andre,Guerra, Celia Fonseca,Bertermann, Ruediger,Troegel, Dennis,Daiss, Juergen O.,Stohrer, Juergen,Bickelhaupt, F. Matthias,Tacke, Reinhold
, p. 2721 - 2737 (2014/06/24)
To understand the silicon α-effect in terms of an enhanced reactivity of the Si-OC bond of α-silanes of the formula type ROSiMe 2CH2X compared to analogous γ-silanes ROSiMe 2(CH2)3X (R = Me, Et; X = functional group), a systematic experimental and computational study of the kinetics and mechanisms of hydrolysis of such compounds was performed. For this purpose, a series of suitable model compounds was synthesized and studied for their hydrolysis kinetics in CD3CN/D2O under basic and acidic conditions, using 1H NMR spectroscopy as the analytical tool. To get more information about the reaction mechanisms, the experimental investigations were complemented by computational studies. These investigations demonstrated that the silicon α-effect cannot be rationalized in terms of a special single effect. The reactivities observed rather result from a summation of different components, such as electronic and steric effects, pD dependence, and hydrogen bonds between the functional group (or even protonated functional group) and the alkoxy leaving group. Therefore, the term silicon α-effect should not be used furthermore to explain the hydrolysis reactivity at the silicon atom of alkoxyorganylsilanes with functional groups in α- or γ-position of the organyl groups (so-called α- or γ-silanes).
