Tris(dimethylamino)silylium ion: structure and reactivity of a dimeric silaguanidinium
Although several strategies for the stabilization of silylium ions have been established, the “π-stabilization” by directly attached π-donor heteroatoms at silicon has not been developed yet. Hydride abstraction from (Me2N)3SiH generates dicationic [(Me2N)3Si+]2 in solution and in the solid state – constituting the dimer of an elusive silaguanidinium ion. The compound can be synthesized on gram scale and is compatible with common organic solvents. However, it readily undergoes spontaneous electrophilic silylation of electron-rich aromatic compounds or initiates a catalytic hydrodefluorination reaction.