Simple Synthesis of 1,3‐Dialkylimidazole‐2‐chalcogenones (E=S, Se, Te) from NHC−CO ₂ Adducts

We present a high yield synthesis of 1-ethyl-3-methyl-imidazole-2-chalcogenones from readily available imidazolium-2-carboxylate zwitterions NHC−CO2 and elemental chalcogens. In sharp contrast to previous syntheses for corresponding thiones selones imidazolium salts bases our reactions proceed fast with full instead low conversion selectivity, decarboxylation is the driving force. Furthermore, this strategy applicable all heavier chalcogens including tellurium. Vacuum sublimation imidazole-2-chalcogenones implemented as convenient method purification leading solid liquid products reported in literature. Newly prepared 1-ethyl-3-methyl-imidazole-2-tellone was characterized by XRD analysis correlation study 125Te NMR 13C shifts respect known representatives. The reaction TMS2S leads NHC−COS, analysis, whereas chalcogen derivatives TMS2E (E=Se, Te) did not react NHC activated CO2.