Zum Mechanismus der Carbodesilylierung 4- bzw. 5-substituierter 2-(Trimethylsilyl)pyridine mit Benzaldehyd

Abstract

An "ylide mechanism" is proposed for the carbodesilylation of 2-(trimethylsily1)pyridines with benzaldehyde. In contrast, 3- and 4-(trimethylsilyl)pyridines, react only in the presence of a base catalyst via pyridyl anions with electrophiles. The rates of the uncatalyzed carbodesilylation reactions of 4-substituted 2-(trimethylsily1)pyridines 2 with benzaldehyde correlate very well with the resonance parameters of the substituents σ1, whereas the rates of 5-substituted 2-(trimethylsily1)pyridines 7 correlate with the inductive substituent parameters σ1 in the Taft equation.