Lewis-base stabilized diiodine adducts with N-heterocyclic chalcogenamides

Oxidation reactions of stable chalcogenamides with iodine are intriguing due to their broad application in various organic syntheses. In the present study we report on the utilization of N-heterocyclic carbene and cyclic-alkyl-amino carbenes L1-3: (L-1: = :C[N(2,6-Pr-i(2)-C6H3)CH](2), L-2: = :C(CH2)(CMe2)(C6H10)N-2,6-Pr-i(2)-C6H3, L-3: = :C(CH2)(CMe2)(2)N-2,6-Pr-i(2)-C6H3) for the syntheses of chalcogenamides L1-3=E (E = S, Se, Te) 1-4 and zwitterionic adducts L1-3=E-I-I 5-8. The synthesis of compounds 1-4 involved the addition reaction of ligand L1-3: and elemental chalcogen. Treatment of 1-4 with iodine resulted in the formation of adducts 5-8. Compounds 5-8 are well characterized with various spectroscopic methods and single-crystal X-ray structural analysis.