Synthesis of Copper(I) Thiolate Complexes in the Thioetherification of Aryl Halides

The copper(I) thiophenolato complexes 1–3 containing 1,10-phenanthroline (phen) and 2,9-dimethyl-1,10-phenanthroline (Me2phen) were isolated in excellent yields from reactions of [CuOtBu]4 with the dative ligands and subsequent addition of 1 equiv of arenethiol. These complexes were characterized spectroscopically and crystallographically. X-ray structural analysis of a single crystal of [(phen)Cu(μ-SC6H5)]2 (1) revealed that this complex adopts a neutral dimeric form with a weak Cu–Cu bonding interaction. These complexes were found to react with iodoarenes to form aryl sulfide products. The intermediacy of such complexes in copper-catalyzed thioetherification of aryl halides was demonstrated by the reactivity with p-tolyl iodide and o-tolyl iodide to form two aryl thioethers with selectivities similar to those of catalytic reactions conducted with the same two iodoarenes.