Ligand-Free Copper-Catalyzed C−S Coupling of Aryl Iodides and Thiols

Abstract

A protocol for the copper-catalyzed aryl-sulfur bond formation between aryl iodides and thiophenols is reported. The reaction is catalyzed by a low amount (1-2.5 mol %) of readily available and ligand-free copper iodide salt. A variety of diaryl thioethers are synthesized under relatively mild reaction conditions with good chemoselectivity and functional group tolerance.

Organometallic Approaches to Carbon–Sulfur Bond Formation

“…Ligand free methods have also been reported [55][56][57][58]. Likely, the function of each ligand is in solubilizing the copper precatalyst and preventing aggregation of any active copper species in solution [59].…”

A Study of Factors Affecting Enantioselectivity in the Oxidation of Aryl Benzyl Sulfides in the Presence of Chiral Titanium Catalysts

“…[35] Prepared by reacting iodobenzene and 2-bromothiophenol in the presence of potassium carbonate and copper iodide in NMP according to a reported procedure. [36] Kugelrohr oven temp. was 117-122°C; p = 0.1 mbar.…”

Recent advances in copper-catalyzed C-S cross-coupling reactions

“…46 The reaction was catalyzed by CuI in presence of K 2 CO 3 base in N-methylpyrrolidinone at 100 ºC (Scheme 19). A variety of diaryl thioethers were synthesized with good functional group tolerance.…”