Metal-free synthesis of sulfonamides via iodine-catalyzed oxidative coupling of sulfonyl hydrazides and amines

Metal-free efficient synthesis of aryl sulfonamides from N-hydroxy sulfonamide and amines

A simple and novel approach has been developed for the synthesis of sulfonamides from N-hydroxy sulfonamide. Notably, the iodine-tert-butyl hydroperoxide (TBHP) system efficiently promoted the sulfonylation reactions of N-hydroxy sulfonamides and amines via the oxidative cleavage of an S-N bond. A variety of aryl sulfonamides were prepared in moderate to good yields using readily available starting materials and the biomass-derived 2-MeTHF solvent. The present method has the advantages of using metal-free reagents, an eco-friendly medium, cost-effective reagents, wide substrate scope, and mild conditions.

A new type of convergent paired electrochemical synthesis of sulfonamides under green and catalyst-free conditions

Our main goal in this work is to synthesize valuable sulfonamide compounds according to the principles of green chemistry and also to present a unique convergent paired mechanism for their synthesis. In this study, we introduced a new type of convergent paired electro-organic synthesis of sulfonamide derivatives via a catalyst, oxidant, halogen and amine-free method. In this research, instead of using toxic amine compounds, an innovative mechanism based on the reduction of nitro compounds and in-situ production of amine compounds was used. The mechanism of electrophile generation is the cathodic reduction of the nitro compound to the hydroxylamine compound and then the anodic oxidation of the hydroxylamine to the nitroso compound. On the other hand, the nucleophile generation mechanism involves the two-electron oxidation of sulfonyl hydrazide to related sulfinic acid at the anode surface. The reaction leading to the synthesis of sulfonamides involves a one-pot reaction of the generated nitroso compound with the produced sulfinic compound.

Structure and Computational Studies of New Sulfonamide Compound: {(4-nitrophenyl)sulfonyl}tryptophan

Synthesis of sulfonamide through an indirect method that avoids contamination of the product with no need for purification has been carried out using the indirect process. Here, we report the synthesis of a novel sulfonamide compound, ({4-nitrophenyl}sulfonyl)tryptophan (DNSPA) from 4-nitrobenzenesulphonylchloride and L-tryptophan precursors. The slow evaporation method was used to form single crystals of the named compound from methanolic solution. The compound was characterized by X-ray crystallographic analysis and spectroscopic methods (NMR, IR, mass spectrometry, and UV-vis). The sulfonamide N-H NMR signal at 8.07–8.09 ppm and S-N stretching vibration at 931 cm−1 indicate the formation of the target compound. The compound crystallized in the monoclinic crystal system and P21 space group with four molecules of the compound in the asymmetric unit. Molecular aggregation in the crystal structure revealed a 12-molecule aggregate synthon sustained by O-H⋯O hydrogen bonds and stabilised by N-H⋯O intermolecular contacts. Experimental studies were complemented by DFT calculations at the B3LYP/6-311++G(d,p) level of theory. The computed structural and spectroscopic data are in good agreement with those obtained experimentally. The energies of interactions between the units making up the molecule were calculated. Molecular docking studies showed that DNSPA has a binding energy of −6.37 kcal/mol for E. coli DNA gyrase (5MMN) and −6.35 kcal/mol for COVID-19 main protease (6LU7).

Construction of Benzenesulfonamide Derivatives via Copper and Visible Light-induced Azides and S(O)2–H Coupling

We here have developed an S(O)2–N coupling between phenylsulfinic acid derivatives and aryl azides by dual copper and visible light catalysis. In this efficient and mild pathway, the reaction produces sulfonamide compounds under redox-neutral condition, which is mechanistically different from the nitrogen nucleophilic substitution reactions. Significantly, this transformation intends to utilize the property of visible light-induced azides to generate triplet nitrene and followed coupling with sulfonyl radicals in situ to achieve structurally diverse benzenesulfinamides in good yields.

Electrochemical Synthesis of Sulfonyl Fluorides from Sulfonyl Hydrazides

The synthesis of sulfonyl fluorides via the reaction of sulfonyl hydrazides and Et3N3HF under electrochemical conditions is reported. Various sulfonyl fluorides were obtained in good yields under a constant current...

Unconventional approaches for the introduction of sulfur-based functional groups

Organosulfur compounds have a pivotal role in the functionalities of many natural products, pharmaceuticals and organic materials. For these reasons, the search for new methodologies for the formation of carbon-sulfur bonds has been the object of intensive work for organic chemists. However, the proposed strategies suffer from various drawbacks, such as volatility, toxicity, and instability of the sulfur sources or the use of VOC solvents. In this review, we summarise the recent protocols which have the goal of obtaining sulfones, thioethers, thiazines, thiazepines and sulfonamides in an unconventional and/or sustainable way. The use of starting materials less invasive and toxic with respect to the traditional reagents, alternative solvents such as water, ionic liquids or deep eutectic solvents, the exploitation of ultrasound and electrochemistry, increasing the efficiency of the process, are reported. Moreover, representative reaction mechanisms are also discussed.

NaI/TBHP-promoted reaction of indole-2-thiones with arylsulfonyl hydrazides: construction of achiral axial 3,3′-biindole-2,2′-dibenzenesulfonothioate derivatives

A new method for the synthesis of achiral axial 3,3′-biindole-2,2′-dibenzenesulfonothioate derivatives from indole-2-thiones with arylsulfonyl hydrazides promoted by NaI/TBHP is disclosed.

Revisiting applications of molecular iodine in organic synthesis

Molecular iodine contributes significantly to organic transformations in synthetic organic chemistry. It works effectively due to its mild Lewis acidic character, ability as an oxidizing agent, good moisture stability, and easy availability.

TBAI-catalyzed selective synthesis of sulfonamides and β-aryl sulfonyl enamines: coupling of arenesulfonyl chlorides and sodium sulfinates with tert-amines

A simple, practical and metal-free method has been developed for the synthesis of sulfonamides and β-arylsulfonyl enamines via the selective cleavage of C-N and C-H bonds through the iodine-catalyzed oxidation of arenesulfonyl chlorides and sodium sulfinates with tert-amines. The method uses commercially available inexpensive catalysts and oxidants, and has a wide substrate scope and operational simplicity.

Iodine-catalyzed sulfonylation of sulfonyl hydrazides with tert-amines: a green and efficient protocol for the synthesis of sulfonamides

This study provides a direct, sustainable and eco-friendly method for the synthesis of various sulfonamides via the sulfonylation of sulfonyl hydrazides with tert-amines. The method utilizes sulfonyl hydrazides to oxidize and couple with tertiary amines through selective cleavage of C–N bonds. In this reaction, molecular iodine was used as the catalyst and t-butyl hydroperoxide was used as the oxidant.

Sustainable and eco-friendly method for the synthesis of various sulfonamides.

Antitubulin sulfonamides: The successful combination of an established drug class and a multifaceted target

Tubulin, the microtubules and their dynamic behavior are amongst the most successful antitumor, antifungal, antiparasitic, and herbicidal drug targets. Sulfonamides are exemplary drugs with applications in the clinic, in veterinary and in the agrochemical industry. This review summarizes the actual state and recent progress of both fields looking from the double point of view of the target and its drugs, with special focus onto the structural aspects. The article starts with a brief description of tubulin structure and its dynamic assembly and disassembly into microtubules and other polymers. Posttranslational modifications and the many cellular means of regulating and modulating tubulin's biology are briefly presented in the tubulin code. Next, the structurally characterized drug binding sites, their occupying drugs and the effects they induce are described, emphasizing on the structural requirements for high potency, selectivity, and low toxicity. The second part starts with a summary of the favorable and highly tunable combination of physical-chemical and biological properties that render sulfonamides a prototypical example of privileged scaffolds with representatives in many therapeutic areas. A complete description of tubulin-binding sulfonamides is provided, covering the different species and drug sites. Some of the antimitotic sulfonamides have met with very successful applications and others less so, thus illustrating the advances, limitations, and future perspectives of the field. All of them combine in a mechanism of action and a clinical outcome that conform efficient drugs.

Crystal structure of N-allyl-4-methyl-benzene-sulfonamide

The title compound, C10H13NO2S, was synthesized by a nucleophilic substitution reaction between allyl amine and p-toluene-sulfonyl chloride. The sulfonate S-O bond lengths are 1.4282 (17) and 1.4353 (17) Å, and the C-N-S-C torsion angle involving the sulfonamide moiety is -61.0 (2)°. In the crystal, centrosymmetric dimers of the title compound are present via inter-molecular N-H⋯O hydrogen bonds between sulfonamide groups. These dimers are linked into ribbons along the c-axis direction through offset π-π inter-actions.

DBN hexafluorophosphate salts as convenient sulfonylating and phosphonylating agents

Air-stable N-sulfonyl and N-phosphonyl DBN hexafluorophosphate salts have been synthesised under mild conditions as sulfonylating and phosphonylating agents. These salts are highly efficient in the sulfonylation and phosphonylation of a range of N- and O-nucleophiles to generate sulfonamides, sulfonate esters, phosphoramidates and phosphonate esters in good yields.

Molecular iodine as a mild catalyst for cross-coupling of alkenes and alcohols

C–C bond formation is one of the most fundamental approaches toward molecular diversity in organic synthesis. In pursuit of environmentally friendlier chemical approaches to organic chemistry, we present a new metal-free method for direct dehydrative cross-coupling of alcohols and alkenes using molecular iodine as a Lewis acid catalyst under solvent-free reaction conditions. The reaction is atom-economical, tolerant to air and allows simple synthetic procedure, furnishing Csp 3–Csp 2 coupling products with yields up to 97%. The method has proved efficient for coupling of secondary benzyl alcohols with phenyl-substituted alkenes.

Synthesis ofN-sulfenyl-sulfoximines and -sulfenamides through a metal-free N–H/S–H dehydrocoupling reaction

A metal-free, iodine-catalyzed N–H/S–H dehydrocoupling reaction of sulfoximines and anilines with various thiols to construct sulfur–nitrogen bonds has been developed.

Study of reactivity of cyanoacetohydrazonoethyl-N-ethyl-N-methyl benzenesulfonamide: preparation of novel anticancer and antimicrobial active heterocyclic benzenesulfonamide derivatives and their molecular docking against dihydrofolate reductase

This article describes the synthesis of some novel heterocyclic sulfonamides having biologically active thiophene 3, 4, 5, 6, coumarin 8, benzocoumarin 9, thiazole 7, piperidine 10, pyrrolidine 11, pyrazole 14 and pyridine 12, 13. Starting with 4-(1-(2-(2-cyanoacetyl)hydrazono)ethyl)-N-ethyl-N-methylbenzenesulfonamide (2), which was prepared from condensation of acetophenone derivative 1 with 2-cyanoacetohydrazide. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, ¹H NMR, ¹³C NMR, ¹⁹F NMR and MS spectral data. All the newly synthesized heterocyclic sulfonamides were evaluated as in-vitro anti-breast cancer cell line (MCF7) and as in-vitro antimicrobial agents. Compounds 8, 5 and 11 were more active than MTX reference drug and compounds 12, 7, 4, 14, 5 and 8 were highly potent against Klebsiella pneumonia. Molecular operating environment performed virtual screening using molecular docking studies of the synthesized compounds. The results indicated that some prepared compounds are suitable inhibitor against dihydrofolate reductase (DHFR) enzyme (PDBSD:4DFR) with further modification.