Biaryl thioether synthesis via CuI catalyzed dominothiolation of aryl halides in the presence of DMAP as ligand

Copper-catalyzed aerobic double functionalization of benzylic C(sp3)-H bonds for the synthesis of 3-hydroxyisoindolinones

A copper-catalyzed aerobic 3-hydroxyisoindolinone synthesis was developed via the benzylic double C(sp³)-H functionalization of 2-alkylbenzamides. In this reaction, molecular oxygen was used as both an oxidant for C(sp³)-H functionalization and an oxygen source. Our method can be extended to diverse benzylic C(sp³)-H bonds and shows excellent functional group tolerance.

Treatment of highly concentrated formaldehyde effluent using adsorption and ultrasonic dissociation on mesoporous copper iodide (CuI) nano-powder

Herein we report a successful degradation of highly concentrated formaldehyde (HCHO, 900 ppm <) effluent from a petrochemical industry using sono-catalytic reaction on highly porous (BET surface of 128 m² g^-1) copper iodide (CuI) nanocrystals as the adsorbent. In this regard, the designed experiments for optimization indicated that the ultrasonic wave (40 kHz) and mass of adsorbent (30 g/L) were significant in HCHO removal so that the combination of the adsorption under ultrasonic degradation resulted in approaching the eliminating efficiency of more than 99%. In this way, GC-MS analysis confirmed the CO₂ production during HCHO degradation. Although the physisorption mechanism (-15.56 kJ/mol) limited the HCHO concentration (~100 ppm) for removal, addition of ultrasonic irradiation significantly improved the process to eliminate 986 ppm of HCHO from the real petrochemical effluent. Moreover, the mechanisms of HCHO decomposition were scrutinized through theoretical studies (density functional theory (DFT)), as well as thermodynamic and kinetics theories. Correspondingly, as calculated from the DFT, the highest adsorption on cleavage plane (111) of the adsorbent was shown to be in complete agreement with its XRD analysis in which the main peak corresponds to the lattice plane (111).

Transition-metal mediated carbon-sulfur bond activation and transformations: an update

Carbon-sulfur bond cross-coupling has become more and more attractive as an alternative protocol to establish carbon-carbon and carbon-heteroatom bonds. Diverse transformations through transition-metal-catalyzed C-S bond activation and cleavage have recently been developed. This review summarizes the advances in transition-metal-catalyzed cross-coupling via carbon-sulfur bond activation and cleavage since late 2012 as an update of the critical review on the same topic published in early 2013 (Chem. Soc. Rev., 2013, 42, 599-621), which is presented by the categories of organosulfur compounds, that is, thioesters, thioethers including heteroaryl, aryl, vinyl, alkyl, and alkynyl sulfides, ketene dithioacetals, sulfoxides including DMSO, sulfones, sulfonyl chlorides, sulfinates, thiocyanates, sulfonium salts, sulfonyl hydrazides, sulfonates, thiophene-based compounds, and C[double bond, length as m-dash]S functionality-bearing compounds such as thioureas, thioamides, and carbon disulfide, as well as the mechanistic insights. An overview of C-S bond cleavage reactions with stoichiometric transition-metal reagents is briefly given. Theoretical studies on the reactivity of carbon-sulfur bonds by DFT calculations are also discussed.

Synthesis of Air-stable, Odorless Thiophenol Surrogates via Ni-Catalyzed C-S Cross-Coupling

Thiophenols are versatile synthetic intermediates whose practical appeal is marred by their air sensitivity, toxicity and extreme malodor. Herein we report an efficient catalytic method for the preparation of S-aryl isothiouronium salts, and demonstrate that these air-stable, odorless solids serve as user-friendly sources of thiophenols in synthesis. Diverse isothiouronium salts featuring synthetically useful functionality are readily accessible by nickel-catalyzed C-S cross-coupling of (hetero)aryl iodides and thiourea. Convenient, chromatography-free isolation of these salts is achieved by precipitation, allowing the methodology to be applied directly to large scales. Thiophenols are liberated from the corresponding isothiouronium salts upon treatment with a weak base, enabling an in situ release/S-functionalization strategy that entirely negates the need to isolate, purify or manipulate these noxious reagents.

DBU-mediated [4 + 1] annulations of donor–acceptor cyclopropanes with carbon disulfide or thiourea for synthesis of 2-aminothiophene-3-carboxylates

Fully substituted 2-aminothiophene-3-carboxylate derivatives were synthesized effectivelyviathe DBU-mediated [4 + 1] annulations of donor–acceptor cyclopropanes with carbon disulfide or thiourea.

Cross C–S coupling reaction catalyzed by copper(i) N-heterocyclic carbene complexes

Copper(i) N-heterocyclic carbenes catalyze the cross C–S coupling reaction with good activities towards aryl halides. A plausible catalytic cycle is proposed, with the support of DFT calculation.