Silver catalyzed C–C and C–S coupling of aryl halides and thiols with boronic acids

Highly active reduced graphene oxide supported Ni nanoparticles for C-S coupling reactions

Air-stable Ni nanoparticles (with particle size ∼ 11 nm) supported on reduced graphene oxide [Ni(0)@RGO] was prepared by a simple and easy procedure. We previously described the Kumada-Corriu C-C cross-coupling reaction between iodo-arenes and Grignard reagents with Ni(0)RGO as a stable and efficient catalyst. This Ni(0)RGO catalyst gave an excellent yield (92%) and good recyclability (up to the 5^th cycle). This communication confirms that the catalyst shows superior efficacy for the C-S coupling reaction, similar to that for the Kumada-Corriu C-C cross-coupling reaction. A catalytic experiment with the Ni(0)@RGO recycled material was also performed. HRTEM study of the reused material after the C-S coupling reaction confirmed the retention of the original (fresh) catalyst structure. It is reusable up to the 7^th cycle without any activity loss.

Thiolate-assisted copper(i) catalyzed C–S cross coupling of thiols with aryl iodides: scope, kinetics and mechanism

The scope and mechanism of the C–S cross coupling of thiophenols with aryl iodides using a Cu(i) catalyst in a ligand-free environment is disclosed.

The journey of C–S bond formation from metal catalysis to electrocatalysis

This perspective describes the journey of C–S bond constructions starting from transition metal catalysis through oxidant catalysis, photocatalysis and very recently employed electrocatalysis by using various sulfur surrogates.

Synthesis of Organosulfur and Related Heterocycles under Mechanochemical Conditions

In the last few decades, ball-milling has received tremendous attention as a "green tool" for conducting various challenging organic transformations under transition-metal-free and solvent-free conditions. Organosulfur and related heterocycles are ubiquitous in numerous biologically active molecules with potential applications, and those molecules could be synthesized from readily available starting materials under mechanochemical conditions without using any hazardous chemical or solvent. This synopsis highlights the green strategies developed in recent times to synthesize organosulfur and related heterocycles under ball-milling conditions.

Nickel-Catalyzed Reductive Thiolation of Unactivated Alkyl Bromides and Arenesulfonyl Cyanides

The cross-electrophile coupling between unactivated alkyl bromides with arenesulfonyl cyanides catalyzed by Ni(acac)₂ under reductive conditions to form unsymmetrical sulfides is developed. This approach for sulfide synthesis is practical, relies on available, unfunctionalized materials such as alkyl (pseudo)halides, and is scalable. This catalytic strategy provides a complementary method for the preparation of unsymmetrical alkyl-aryl sulfides under mild conditions with good functional group tolerance.

Organophotoredox-Catalyzed Formation of Alkyl-Aryl and -Alkyl C-S/Se Bonds from Coupling of Redox-Active Esters with Thio/Selenosulfonates

A mild organophotoredox synthetic protocol for forming a Csp3-S/Se bond by reacting widespread redox-active esters with thio/selenosulfonates has been developed. The power of the synthetic manifold is fueled by an unprecedented broad substrate scope and wide functional group tolerance.

Synthesis of diaryl sulfides based on copper-doped OMS-2

We describe a practical protocol for efficiently preparing diaryl sulfide compounds using Cu–OMS-2 as the catalyst. Cu–OMS-2 originates from manganese oxide octahedral molecular sieves modified with copper ions and catalyzes the C–S coupling reaction of substituted thiophenols and aryl halides. This protocol has the advantages of environmental friendliness, simple operation, high yields, good tolerance of functional groups, and the Cu–OMS-2 catalytic material can be recycled several times.

N-Aminopyridinium Ylide-Directed, Copper-Promoted Chalcogenation of Arene C-H Bonds

N-Aminopyridinium ylide-directing group is employed for copper-promoted chalcogenation of sp² C-H bonds with aryl and alkyl disulfides as well as diphenyl diselenide. Reactions proceed in hexafluoroisopropanol (HFIP) solvent at elevated temperatures and are promoted by copper(II) acetate.

Advances in Cu and Ni-catalyzed Chan–Lam-type coupling: synthesis of diarylchalcogenides, Ar2–X (X = S, Se, Te)

Advances in the Cu and Ni-catalyzed Chan–Lam-type coupling of aryl/heteroarylboronic acids with various chalcogen sources for diarylsulfide, diarylselenide and diaryltelluride synthesis are covered in this review.

Nickel-catalyzed reductive thiolation and selenylation of unactivated alkyl bromides

Chalcogen-containing compounds have received considerable attention because of their manifold applications in agrochemicals, pharmaceuticals, and material science. While many classical methods have been developed for preparing organic sulfides, most of them exploited the transition-metal-catalyzed cross-couplings of aryl halides or pseudo halides with thiols or disulfides, with harsh reaction conditions usually being required. Herein, we present a user-friendly, nickel-catalyzed reductive thiolation of unactivated primary and secondary alkyl bromides with thiosulfonates as reliable thiolation reagents, which are easily prepared and bench-stable. Furthermore, a series of selenides is also prepared in a similar fashion with selenosulfonates as selenolation reagents. This catalytic method offers a facile synthesis of a wide range of unsymmetrical alkyl-aryl or alkyl-alkyl sulfides and selenides under mild conditions with an excellent tolerance of functional groups. Likewise, the use of sensitive and stoichiometric organometallic reagents can be avoided.

Engineered C-S Bond Construction

Due to the versatile applications of thioethers and thioesters in organic synthesis, medicinal chemistry, the pharmaceutical industry, and materials science, recently the construction of C-S bonds has emerged as the forefront in the field of cross-coupling reactions. Enough progress has been made in this direction by using both metal catalysis and other alternative processes. A brief review of the recent developments in the area of C-S coupling reaction is described.

Regio- and stereoselective syntheses of allylic thioethers under metal free conditions

A metal-free, regio and stereoselective synthesis of allylic thioethers using densely functionalized allyl iodides and aryl/alkyl disulfides as coupling partners, provided the resulting allyl aryl thioethers in 62–92% isolated yields is described.

Silver-catalyzed direct thiolation of quinones by activation of aryl disulfides to synthesize quinonyl aryl thioethers

A silver-catalyzed coupling reaction of quinones with aryl disulfides for the synthesis of quinonyl aryl thioethers is described. In the presence of AgOAc (0.2 equiv)/dppp (0.24 equiv) as the catalyst, (NH4)2S2O8 (3.0 equiv) as the oxidant, and Bu4NBF4 (1.0 equiv) as the additive, the reaction is simple, provides high yield (up to 88% yield), and possesses a broad substrate scope. The reaction is believed to proceed via direct activation of disulfides evidenced by observation of a metathesis reaction between two different disulfides placed together under the reaction conditions and (13)C NMR spectroscopy analysis.

A mild and facile synthesis of aryl and alkenyl sulfides via copper-catalyzed deborylthiolation of organoborons with thiosulfonates

A simple, efficient, and odorless deborylthiolation of aryl- and alkenylborons with thiosulfonates has been achieved under mild conditions using a copper catalyst.

Ligand-free Cu-catalyzed odorless synthesis of unsymmetrical sulfides through cross-coupling reaction of aryl/benzyl/alkyl halides with an aryl boronic acid/S8 system as a thiolating agent in PEG

Efficient one-pot, one-step synthesis of unsymmetrical sulfides has been reported under mild reaction conditions with good yields in green solvent.