Ligand‐free copper‐catalysed direct synthesis of diaryl sulfides and diaryl disulfides in wet poly(ethylene glycol)

Abstract

An improved protocol has been developed for the one‐pot CuI‐catalysed preparation of symmetric diaryl sulfides from their available aryl halides in the presence of thiourea as sulfur transfer agent and in the absence of both ligand and organic solvent. This catalytic system was also used for the high‐yielding preparation of diaryl disulfides in the presence of C2Cl6 as oxidant.

A review on the latest progress of C‐S cross‐coupling in diaryl sulfide synthesis: Update from 2012 to 2021

“…In addition, the use of CuI as catalyst is reported for the synthesis of diaryl sulfides from aryl halides with thiourea. [ 44 ]…”

Synthesis and reactivity of succinylthioimidazolium salts: A unified strategy for the preparation of thioethers

“…NaOH/H2O, 90 °C; K2CO3/H2O, 80 °C or Na2CO3/wet PEG 200, 120 °C) to afford the corresponding (hetero)aryl thiolates (Scheme 70). [248,249] 65 Scheme 70: Thiolation of electron-rich (hetero)arenes with TMTU as sulfur-containing precursor Surprisingly, no study on the corresponding initial C-H activation of (hetero)arenes with halogenated imidazole-2-thiones has been reported to date, even if the electronic structure of those (dihalo)imidazothions has been already discussed in detail in the literature. [250] The only published methodologies for the synthesis of analogous to 82 arylthioimidazolium salts 83 are based on the alkylation of imidazole thioethers by strong alkylation reagents like alkyl iodides, [248,251] by reaction of a imidazole carbene with a diaryldisulfide [252] or by treatment of 2chlorimidazolium salts with thiolates (Scheme 71).…”