2020/08/12 by Alexander Hinz · 1 voice
Chemistry · #Synthesis and characterization of novel inorganic/organometallic compounds #Organoboron and organosilicon chemistry #Coordination Chemistry and Organometallics
paper · pdf · doi:10.1002/anie.202009874
openalex publication_date 2020/08/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Abstract Mono‐coordinated silicon(II) cations are predicted to be reactive ambiphiles, combining the typically high Lewis acidity of silicon cations with nucleophilicity due to the presence of an electron pair at the same atomic centre. Here, a carbazole‐derived scaffold was used to isolate salts with a mono‐coordinated silicon(II) cation, [RSi] + (R=bulky carbazolyl substituent), by halide abstraction from a base‐free halosilylene, RSiI, with Ag[Al(O t Bu F ) 4 ]. Despite the bulk of the carbazolyl moiety, the silylenylium cation [RSi] + retains high reactivity. It was shown to react with an amine to form three bonds at the silicon atom in one reaction which conforms with the notion of a “supersilylene”. The resulting silylium cation [RSi(H)NR′ 2 ] + (in the formal oxidation state Si IV ) obtained by oxidative addition of an NH bond at [RSi] + is even more acidic than the silylenylium cation (Si II ) due to the absence of a lone pair of electrons the silicon atom.