The Palladium Catalyzed Nucleophilic Substitution of Aryl Halides by Thiolate Anions

Abstract

In the presence of a catalytic amount of tetrakis(triphenylphosphine) palladium, phenyl and methyl or methoxyphenyl iodides and bromides were found to react with thiolate anions in alcoholic solvents, to give the corresponding aryl sulfides in excellent yield. The reaction is useful to prepare symmetrical or unsymmetrical diaryl sulfides and aryl alkyl sulfides. The reaction mechanism does not involve aryl halide radical anions, but is thought to involve oxidative addition of aryl halide to Pd(0), nucleophilic substitution on the adduct followed by reductive elimination.

Palladium on Charcoal as a Recyclable Catalyst for CS Cross‐Coupling of Thiols with Aryl Halides under Ligand‐Free Conditions

“…Since Migita and co-workers first reported the PdA C H T U N G T R E N N U N G (PPh 3 ) 4 -catalyzed C À S coupling of aryl iodides with thiols, [2] various palladium catalytic systems with different ligands [3] have realized some success and nickel-, [4] cobalt-, [5] copper-, [6] indium-, [7] and more recently iron-based [8] catalytic systems have also been studied. Still, the development of new, efficient catalytic systems for C À S cross-coupling is of great importance.…”

Synthesis of new 4-[2-(alkylamino)ethylthio]pyrrolo[1,2-a]quinoxaline and 5-[2-(alkylamino)ethylthio]pyrrolo[1,2-a]thieno[3,2-e]pyrazine derivatives, as potential bacterial multidrug resistance pump inhibitors

“…Using this protocol, the arylsulfide 7a was synthesised (yield: 80%). The reaction of 6a with the thiolate anion, prepared by the action of t-BuOK on the N,N-diethylaminoethylthiol, in the presence of a catalytic amount of tetrakis(-triphenylphosphine)palladium in n-butanol (method D) was also found to be useful in the preparation of the sulfide 7a (66%) [36,37].…”

Microwave‐Assisted Cross‐Coupling for the Construction of Diaryl Sulfides

“…[18][19][20] Migita and co-workers reported the first cross-coupling reaction of aryl halides and thiols for the construction of aryl-sulfur bond by using catalyst Pd(PPh 3 ) 4 and base NaOt-Bu in ethanol at reflux or in DMSO at 90°C. 21 Recently, catalysts containing transition metals such as palladium, 22,23 cobalt, 24 nickel, 25 and copper 19,26 have been capitalized in the condensation reactions of thiolates and aryl halides. To probe the utility of metal-containing ligands or auxiliary compounds in organic synthesis, a great number of applications for various coupling reactions have been realized with improvement in yields.…”