Regioselective copper(I)-catalyzed C–H hydroxylation/C–S coupling: expedient construction of 2-(styrylthio)phenols

Enaminone-based carboxylic acids as novel non-classical carbonic anhydrases inhibitors: design, synthesis and in vitro biological assessment

In searching for new molecular drug targets, Carbonic Anhydrases (CAs) have emerged as valuable targets in diverse diseases. CAs play critical functions in maintaining pH and CO₂ homeostasis, metabolic pathways, and much more. So, it is becoming attractive for medicinal chemists to design novel inhibitors for this class of enzymes with improved potency and selectivity towards the different isoforms. In the present study, three sets of carboxylic acid derivatives 5a-q, 7a-b and 12a-c were designed, developed and evaluated for the hCA inhibitory effects against hCA I, II, IX and XII. Compounds 5l, 5m, and 5q elicited the highest inhibitory activities against hCA II, IX and XII. In summary, structural rigidification, regioisomerism and structural extension, all played obvious roles in the degree of hCA inhibition. This present work could be a good starting point for the design of more non-classical selective hCA inhibitors as potential targets for several diseases.

Iron-catalyzed cascade reaction of C(sp3)-Se bond cross-coupling/C-N bond formation

An iron-catalyzed cascade reaction of C(sp3)-Se bond cross-coupling/C-N bond formation was developed. Various 5,13a-dihydro-6H,8H-benzo[5,6][1,3]selenazino[2,3-a]isoquinolin-8-one derivatives were synthesized under mild conditions starting from 1,2,3,4-tetrahydroisoquinolines and 2-hydroselenobenzoic acids. This protocol provides an economical approach for C(sp3)-Se bond formation.

A nickel-catalyzed tandem reaction involving cyclic esterification/C-S bond formation for synthesizing 5-oxa-11-thia-benzofluoren-6-ones

A nickel-catalyzed tandem reaction involving cyclic esterification/C–S bond formation has been developed. Starting from samples containing 3-(2-hydroxy-phenyl)-acrylic acids with 2-halide-benzenethiols, versatile biologically active 5-oxa-11-thia-benzofluoren-6-one compounds were efficiently synthesized in good to high yields. This new methodology provides an economical approach toward C–S bond formation.

A nickel-catalyzed tandem reaction involving cyclic esterification/C–S bond formation has been developed.

Copper-catalyzed C–S direct cross-coupling of thiols with 5-arylpenta-2,4-dienoic acid ethyl ester

A selective copper (Cu)-catalyzed C–S bond direct cross-coupling of thiols with 5-arylpenta-2,4-dienoic acid ethyl ester was developed. Notably, various biologically active 5-phenyl-3-phenylsulfanylpenta-2,4-dienoic acid ethyl ester derivatives were efficiently synthesized under moderate conditions. Finally, a plausible Cu(i)/Cu(iii) reaction mechanism was proposed.

A selective copper (Cu)-catalyzed C–S bond direct cross-coupling of thiols with 5-arylpenta-2,4-dienoic acid ethyl ester was developed.

Mechanistic Study of Copper-Catalyzed C-H Hydroxylation/C-S Coupling by ESI-HR MS and DFT Calculations

The reaction mechanism of Cu-catalyzed C-H hydroxylation/C-S coupling was studied using electrospray ionization high resolution mass spectrometry (ESI-HR MS) and density functional theory calculations (DFT). Notably, a series of Cu^I and Cu^III complexes were observed as key intermediates and identified using ESI-HR MS. Furthermore, a catalyst cycle involving proton abstraction/oxidative addition/reductive elimination was proposed. This study is important and valuable with respect to C-H functionalization.

Iron(ii)-catalyzed sulfur directed C(sp3)–H bond amination/C–S cross coupling reaction

An efficient iron(ii)-catalyzed sulfur directed C(sp³)–H bond amination/C–S cross coupling reaction has been developed, and the mechanism corresponds to a Fe(ii)/Fe(iii) catalytic cycle.

Ligand-free Cu-catalyzed O-arylation of aliphatic diols

Coupling reaction between aryl iodides with aliphatic diols was realized with a ligand-free copper catalyst. This method was successfully applied in the process of scale-up synthesis of medicinal candidate product EMB-3.

Pd-catalyzed C–N coupling of vinylbromides and sulfonimidamides: a facile synthesis of N′-vinylsulfonimidamides

N′-Vinyl sulfonimidamides were synthesized through Pd-catalyzed C–N coupling; the product's utility were further demonstrated by preparing N′-alkyl sulfonimidamides through hydrogenation.

Fabrication of magnetic amino-functionalized nanoparticles for S-arylation of heterocyclic thiols

The aminosilane coupling agent and polyethylene imine-600 were loaded onto magnetic nanoparticles to obtain magnetic nanoligands (MNLs) A, B, C and D.

Disulfides as efficient thiolating reagents enabling selective bis-sulfenylation of aryl dihalides under mild copper-catalyzed conditions

Selective bis-sulfenylation reactions of aryl dihalides have been achieved by copper-catalyzed C–S coupling reactions under mild conditions of refluxing EtOH (80 °C).