Chlorine/Methyl Exchange Reactions in Silylated Aminostibanes: A New Route To Stibinostibonium Cations

The Lewis acid assisted triflate/methyl, azide/methyl, and chlorine/methyl exchange reactions between silicon and antimony have been studied in the reaction of R­(Me3Si)­N–SbCl2 (R = Ter) with AgOTf, AgN3, KOtBu, GaCl3, and Me3SiN3/GaCl3, resulting in the formation of different methylantimony compounds. Furthermore, R­(Me3Si)­N–SbCl2 (R = SiMe3) was reacted with GaCl3 at low temperatures to yield a hitherto unreported amino­(chloro)­stibenium cation, the proposed intermediate in methyl exchange reactions. Tetrachloridogallate salts bearing different stibinostibonium cations such as [(Me3Sb)­SbMe2]+ and [(Me3Sb)2SbMe]2+ along with the GaCl3 adduct of SbMe3 were isolated from such R­(Me3Si)­N–SbCl2/GaCl3 mixtures (R = SiMe3) at ambient temperatures, depending on the reaction parameters.