Saturated NHC Derived Dichalcogen Dications

Abstract

Herein, the synthesis and characterization of dicationic dichalcogenide compounds [(SIPr)E]2(OTf)2 (3a-E) (E = S, Se, Te) based on a saturated N-heterocyclic carbene (NHC), SIPr [SIPr = C{N(Dipp)CH2}2, Dipp = 2,6-iPr2C6H3] are reported. Treatment of SIPr (1a) with elemental chalcogens affords the heavier ketone derivatives (SIPr)E (2a-E), which readily undergo oxidative E–E coupling reactions with triflic anhydride to yield the corresponding products 3a-E. Compounds 3a-E are air-stable crystalline solids and were characterized by NMR and UV/Vis spectroscopy as well as by X-ray diffraction methods.