Derivate des Imidazols, XIX. Koordination oder Reduktion? Zur Reaktion von 1,3‐Diisopropyl‐4,5‐dimethylimidazol‐2‐yliden mit Schwefelhalogeniden und Schwefeloxidhalogeniden

Imidazole Derivatives, XIX Part XVIII: Ref.[1] . — Coordination or reduction? On the Reaction of 1,3‐Diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene with Sulfur Halides and Sulfur Oxygen Halides Herrn Professor Max Herberhold zum 60. Geburtstag gewidmet. The reaction of 1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene (4, Im) with sulfur halides and sulfur oxygen halides may be described as a coordination (1) or reduction (2) process in respect to the sulfur centre. With SCl2 and SOCl2 the hypervalent sulfur compounds Im · SCl2 (5) and Im · S(O)Cl2 (13) are obtained. The SF2 adduct Im · SF2 (11) is formed on treatment of 5 with AgF. 13 is alkylated by methyl iodide to give the Im · S(Me)OCl2 cation (15). Surprisingly, reduction of the sulfur centre (2) occurs on treatment of 4 with SF4 to form the ImF+SF3− salt 18 containing the new SF3 anion. As expected, the same type of reaction occurs with the sulfuryl halides SO2ClF and SO2F2 to give the fluorosulfites ImCl+‐SO2F− (21) and ImF+SO2F− (23). The X‐ray structures of 5, 13 and 23 are reported.