Low‐Valent Silicon Cations with Two‐Coordinate Silicon and Aromatic Character

Abstract

Desperately seeking silyenylium: Electrophilic attack of silylene 1 (R=2,6-diisopropylphenyl) by B(C6F5)3 and H+ afforded the silylene-like zwitterion 2 and the “free” silyliumylidene cation 3 (in the presence of the noncoordinating [B(C6F5)4]− anion), respectively. Cations 2 and 3 represent a novel class of low-coordinate silicon cations with promising potential for the synthesis of heteroleptic silylenes.