Polar X–H Bond (X = O, S, N) Activation at a Cage Silanide

Abstract

Low‐valent silicon compounds such as neutral silylenes display versatile reactivity for the activation of small molecules. In contrast, their anionic congeners silanides ([R3Si–]) have primarily been investigated for their nucleophilic reactivity. Here we show that incorporating a silanide center in a bicyclic cage structure allows for formal oxidative addition of polar element‐hydrogen bonds (RX–H, R = aromatic residue, X = O, S, NH). The resulting hydrosilicates were isolated and characterized structurally and spectroscopically. Density Functional Theory (DFT) calculations and experimental observations support an ionic mechanism for RX–H bond activation. Finally, the reactivity of the RS–H bond adduct was further investigated, revealing that it behaves as a Lewis pair upon facile heterolytic cleavage of the Si–S bond.