Imidazole derivatives. Part XIX. Coordination or reduction? On the reaction of 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene with sulfur halides and sulfur oxygen halides.
In: Chemische Berichte (Chem.Ber.), Jg. 129 (1996) ; Nr. 12, S. 1579-1586
Zeitschriftenaufsatz / Fach: Chemie
The reaction of 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (I) with sulfur halides and sulfur oxygen halides may be described as a coordination or redn. process in respect to the S center. With SCl2 and SOCl2 the hypervalent S compds. II [R = SCl2, S(O)Cl2] are obtained. The SF2 adduct II (R = SF2) is formed on treatment of II (R = SCl2) with AgF. Compd. II [R = S(O)Cl2] is alkylated by MeI to give the cation II [R = S(Me)OCl2+]. Surprisingly, redn. of the S center occurs on treatment of I with SF4 to form the cation II (R = F+) with SF3- as anion. The same type of reaction occurs with SO2ClF and SO2F2 to give the fluorosulfites II (R = Cl+, F+) with SO2F- as anion. The x-ray structures of Im.SCl2, Im.S(O)Cl2, and ImF+SO2F- are reported.