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.

Metal-Free Highly Regioselective 1,4-Sulfonyliodination of 1,3-Enynes

Herein, a novel, practical, and green synthetic method using readily available 1,3-enynes with sulfonyl hydrazides and I₂ through tert-butyl hydroperoxide (TBHP)-mediated 1,4-sulfonyliodination has been developed for synthesizing various tetrasubstituted allenyl iodides under metal-free conditions. Notably, the proposed method exhibits a broad substrate scope, operational simplicity, tolerance to air, high functional-group tolerance, satisfactory yields, and excellent regioselectivity as well as involves the use of cost-effective reagents such as green oxidants.

Synthesis of new pyridines with sulfonamide moiety via a cooperative vinylogous anomeric-based oxidation mechanism in the presence of a novel quinoline-based dendrimer-like ionic liquid

In the present study, we reported the synthesis of a novel quinoline-based dendrimer-like ionic liquid. After characterization of the mentioned ionic liquid with suitable techniques such as Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX), elemental mapping, thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG), its catalytic performance was investigated in the synthesis of new pyridines with sulfonamide moiety via a cooperative vinylogous anomeric-based oxidation mechanism under mild reaction conditions. All target molecules were achieved in short reaction times and high yields.

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.

Transition-metal-free S–N bond formation: synthesis of 5-amino-1,2,4-thiadiazoles from isothiocyanates and amidines

A novel and green method for the synthesis of 5-amino-1,2,4-thiadiazoles has been developed by the reaction of isothiocyanates with amidines.

Synthesis of N-arylsulfonamides through a Pd-catalyzed reduction coupling reaction of nitroarenes with sodium arylsulfinates

A novel one-step direct reductive coupling reaction between nitroarenes and sodium arylsulfinates was realized in the presence of an inexpensive Pd/C catalyst. In this procedure, readily available nitroarenes are employed as the nitrogen sources, and sodium arylsulfinates serve as both coupling partners and reductants. The method features high efficiency by using cheap Pd/C with low catalyst loading and good functional group tolerance in the absence of any additional reductants or ligands. This facile and mild synthetic method enables the high efficiency synthesis of functionalized N-arylsulfonamides from readily available substrates.

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.

Metal-free I2O5-mediated direct construction of sulfonamides from thiols and amines

A simple and efficient metal-free I₂O₅-mediated one-pot procedure for the construction of sulfonamides from thiols and amines has been developed.

Copper-catalyzed oxidative decarboxylative coupling of α-keto acids and sulfoximines

The formation of N-aroylsulfoximines via a copper-catalyzed oxidative decarboxylative coupling of α-keto acids with NH-sulfoximines is reported.

Site-selective oxidative C–H sulfonylation of 8-acylaminoquinolines and anilides under metal-free conditions

A highly site-selective oxidative C–H sulfonylation method for 8-acylaminoquinolines and anilides with sulfonyl chlorides has been developed, which provided C5-sulfonylated quinolines and para-sulfonylated anilides respectively.

In Situ Generated HypoIodite Activator for the C2 Sulfonylation of Heteroaromatic N-oxides

A mild approach for direct C2 sulfonylation of heteroaromatic N-oxides with sulfonyl hydrazides affording 2-sulfonyl quinolines/pyridines has been developed. A variety of heteroaromatic N-oxides and sulfonyl hydrazides participate effectively in this transformation which uses hypoiodites (generated in situ from NaI and TBHP) as a means of substrate activators. In this reaction, the N-oxide plays a dual role, acting as a traceless directing group as well as a source of oxygen atom.

A general iodine-mediated synthesis of primary sulfonamides from thiols and aqueous ammonia

An efficient, practical and green methodology for the synthesis of primary sulfonamides has been developed. Various types of thiols can be applied as substrates and the desired sulfonamides can be obtained in good to excellent yields.