TBAI-mediated sulfenylation of arenes with arylsulfonyl hydrazides in DPDME

Sustainable Sulfonylation and Sulfenylation of Indoles with Thiols through Hexamolybdate/H2O2-Mediated Oxidative Dehydrogenation Coupling

Arylsulfonylindole and arylsulfenylindole motifs stand as privileged scaffolds in drug discovery. Traditional methods for synthesizing these molecules have relied mainly on prefunctionalized precursors, involving multistep processes and generating a large amount of waste. In this study, we present a modular protocol for the preparation of 3-sulfonylindoles and 3-sulfenylindoles using indoles and thiols as starting materials via hexamolybdate/H2O2-mediated oxidative dehydrogenative C-S coupling. Notably, this method features a simple reaction setup and uses readily available thiols as a sulfide source, H2O2 as a green oxidant and oxygen source, alcohol as solvent, recyclable hexamolybdate as a catalyst, and water as the sole byproduct. These metrics are an acceptable green organic synthesis process.

Iodophor-Catalyzed Disulfenylation of Amino Naphthalenes with Aryl Sulfonyl Hydrazines

An iodophor-catalyzed direct disulfenylation of amino naphthalenes with aryl sulfonyl hydrazines in water was developed. A series of aryl sulfides were obtained in moderate to excellent yields. The advantages of this green protocol were the simple reaction conditions (metal-free, water as the solvent, under air), the odorless and easily available sulfur reagent, the broad substrate scope, and gram-scale synthesis. Moreover, the potential application of aryl sulfides was exemplified by further transformations.

Pushing Boundaries: What's Next in Metal-Free C-H Functionalization for Sulfenylation?

The synthesis of thioether derivatives has been explored widely due to the potential application of these derivatives in medicinal chemistry, pharmaceutical industry and material chemistry. Within this context, there has been an increasing demand for the environmentally benign construction of C-S bonds via C-H functionalization under metal-free conditions. In the present article, we highlight recent developments in metal-free sulfenylation that have occurred in the past three years. The synthesis of organosulfur compounds via a metal-free approach using a variety of sulfur sources, including thiophenols, disulfides, sulfonyl hydrazides, sulfonyl chlorides, elemental sulfur and sulfinates, is discussed. Non-conventional strategies, which refer to the development of thioether derivatives under visible light and electrochemically mediated conditions, are also discussed. The key advantages of the reviewed methodologies include broad substrate scope and high reaction yields under environmentally benign conditions. This comprehensive review will provide chemists with a synthetic tool that will facilitate further development in this field.

Iodine-catalyzed regioselective direct sulfenylation of uracil with sulfonyl hydrazide as sulfur source under solvent free conditions

A facile method was developed for the selective thioetherification of uracils using sulfonyl hydrazide as the thioetherification reagent. This method offers advantages such as avoiding the use of additives and expensive metal catalysts, and providing good to excellent yields of various uracil thioethers. Experimental studies have demonstrated that the reaction follows a free radical pathway. Notably, the reaction can be carried out without solvent.

Synthesis of Asymmetric Diaryl Sulfides via HI-Mediated C(sp2)-H Sulfenylation of Arenes with Sodium Sulfinates

A novel hydroiodic acid-promoted metal-free C(sp²)-H sulfenylation of electron-rich arenes was developed using stable and easy-to-handle sodium sulfinates as sulfur sources. Diverse kinds of asymmetric aryl sulfides were afforded in good yields from various commercially available aromatic substrates under mild conditions. Comprehensive mechanistic experiments demonstrate that RSO₂SR and RSSR are the key intermediates responsible for the redox process.

Design, synthesis, cytotoxicity, and molecular docking studies of novel thiazolyl-hydrazone derivatives as histone lysine acetyl-transferase inhibitors and apoptosis inducers

Compounds containing both thiazole and arylsulfone moieties are recognized for their high biological activity and ability to fight a variety of ailments. Thus, in this context, new derivatives of (thiazol-2-yl)hydrazone with an arylsulfone moiety were synthesized as CPTH2 analogs with potent anti-histone lysine acetyl-transferase activity. Compounds 3, 4, 10b, and 11b showed an excellent inhibitory effect on P300 (E1A-associated protein p300), compared to CPTH2. Among all the tested derivatives, compound 10b revealed the highest activity against both P300 and pCAF. In addition, the new hits were tested for anticancer efficacy against two leukemia cell lines. Most of them showed a moderate to potent antitumor effect on the k562 and CCRF-CEM cell lines. Interestingly, the activity of compound 10b against the k562 cell line was found to be higher than that of CPTH2. Furthermore, it showed a good safety profile, better than CPTH2 on normal cells. Molecular docking analysis was carried out to reveal the crucial binding contacts in the inhibition of the P300 and pCAF enzymes.