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Background: Antimicrobial resistance is a persistent problem regarding infection treatment and calls for developing new antimicrobial agents. Inhibition of bacterial β-ketoacyl acyl carrier protein synthase III (FabH), which catalyzes the condensation reaction between a CoA-attached acetyl group and an ACP-attached malonyl group in bacteria is an interesting strategy to find new antibacterial agents. Objective: The aim of this work was to design and synthesize arylsulfonylhydrazones potentially FabH inhibitors and evaluate their antimicrobial activity. Methods: MIC50 values of sulfonylhydrazones against E. coli and S. aureus were determined. An-tioxidant activity was evaluated by DPPH (1-1’-diphenyl-2-picrylhydrazyl) assay and cytotoxicity against LL24 lung fibroblast cells was verified by MTT method. Principal component analysis (PCA) was performed in order to suggest a structure-activity relationship. Molecular docking allowed to propose sulfonylhydrazones interactions with FabH. Results: The most active compound showed activity against S. aureus and E. coli, with MIC50 = 0.21 and 0.44 μM, respectively. PCA studies correlated better activity to lipophilicity and molecular docking indicated that sulfonylhydrazone moiety is important to hydrogen-bond with FabH while methylcatechol ring performs π-π stacking interaction. The DPPH assay revealed that some sulfonylhydrazones derived from the methylcatechol series had antioxidant activity. None of the evaluated compounds was cytotoxic to human lung fibroblast cells, suggesting that the compounds might be considered safe at the tested concentration. Conclusion: Arylsufonylhydrazones is a promising scaffold to be explored for the design of new antimicrobial agents.

Under superacidic conditions, aniline and indole derivatives are sulfonylated at low temperature with easy-to-access arenesulfonic acids or arenesulfonyl hydrazides. By modification of the functional-group directing effect through protonation, this method allows nonclassical site functionalization by overcoming the innate regioselectivity of electrophilic aromatic substitution. This superacid-mediated sulfonylation of arenes is complementary to existing methods and can be applied, through protection by protonation, to the late-stage site-selective functionalization of natural alkaloids and active pharmaceutical ingredients.

We report herein a direct method to synthesize 4-aryl-3-butenoic acid through a carboxylic-acid-directed oxidative Heck reaction. The various 4-aryl-3-butenoic acids are easily prepared in moderate to good yields. In view of the promising bioactivity of 4-phenyl-3-butenoic acid previously reported, its derivatives reported here may be bioactive.

An unprecedented electrochemical heterodifunctionalization of α-CF3alkenes with benzenesulfonyl hydrazides was accomplished in this work, wherein a β-sulfonyl and a α-hydroxyl group were simultaneously incorporated across the olefinic double bond in a single operation. Consequently, a series of potentially medicinally valuable and densely functionalized α-trifluoromethyl-β-sulfonyl tertiary alcohols were assembled under mild conditions. Electrochemically-driven oxidative 1,2-difunctionlization of electron-deficient alkenes well obviates the need for oxidizing reagents, thus rendering this protocol more eco-friendly.

An environmentally friendly and efficient electrochemical fluorosulfonylation of styrenes has been developed. With the use of sulfonylhydrazides and triethylamine trihydrofluoride, a diverse array of β-fluorosulfones could be readily obtained. This reaction features mild conditions and a broad substrate scope, which could also be conveniently extended to a gram-scale preparation.

A tunable and practical transformation of structurally diverse sulfonyl hydrazides into thiosulfonates in the presence of Rongalite (NaHSO 2·CH 2O) was developed. Transition-metal-free conditions, operational simplicity, and readily available reagents are the striking features of this protocol. It is the first example for the synthesis of thiosulfonates using sulfonyl hydrazides with the assistance of reductant. Additionally, the mechanistic studies revealed that this transformation probably undergoes via a reducing-coupling pathway.

An efficient iodine-mediated coupling of cyclic amines with sulfonyl hydrazides is reported. This transformation opens a new route to the synthesis of vinyl sulfones derivatives, which is a common structural motif in natural products and pharmaceuticals. Tentative mechanistic studies suggest that this reaction is likely to involve a radical process.

We have developed a protocol for the NaHSO3-promoted esterification of sulfonyl hydrazides with alcohols for the synthesis of sulfinic esters. Various sulfonyl hydrazides could be converted to the corresponding sulfinic esters in good to high yields. The merits of this protocol include mild transition-metal-free reaction conditions, an inexpensive and available reagent, and operational simplicity. Controlled experiments reveal that this transformation probably undergoes via a radical pathway. (Figure presented.).

An electrooxidative direct difunctionalization of internal alkynes with sulfonyl hydrazides has been developed for the construction of sulfonated enethers. In this transformation, metal catalysts or stoichiometric amount of oxidants are not required and molecular nitrogen and hydrogen are the sole byproducts, providing a simple and green approach for preparing various sulfonyl tetrasubstituted alkenes. Notably, the protocol could be efficiently scaled up and the follow-up procedures of the corresponding functionalized alkenes demonstrate the practicality of the electrochemical synthesis.

A copper-catalyzed radical cross-coupling of cyclobutanone oxime esters with sulfonyl hydrazides has been developed. The copper-based catalytic system proved crucial for cleavage of the C-C bond of cyclobutanone oximes and for selective C-S bond-formation involving persistent sulfonyl-metal radical intermediates. This protocol is distinguished by the low-cost catalytic system, which does not require ligand, base, or toxic cyanide salt, and by the use of readily accessible starting materials, as well as broad substrate scope, providing an efficient approach to various diversely substituted cyano-containing sulfones.

A new electrochemical three-component annulation-iodosulfonylation of 1,5-enyne-containing para-quinone methides (p-QMs) has been established by using available arylsulfonyl hydrazides and potassium iodide under environmentally benign conditions. The electrosynthesis offers sustainable and efficient access to construct spirocyclohexadienone-containing (E)-indenes without any additional catalyst or oxidant through a sulfonyl-radical-triggered 1,6-addition and an I+-mediated ipso-cyclization cascade. Notably, potassium iodide plays the triple role of an electrolyte, a redox catalyst, as well as an iodination reagent.

A highly efficient sulfonylation of para-quinone methides with sulfonyl hydrazines in water has been developed on the basis of the mode involving a tetrabutyl ammonium bromide (TBAB)-promoted sulfa-1,6-conjugated addition pathway. This reaction provides a green and sustainable method to synthesize various unsymmetrical diarylmethyl sulfones, showing good functional group tolerance, scalability, and regioselectivity. Further transformation of the resulting diarylmethyl sulfones provides an efficient route to some functionalized molecules.

A new route for the synthesis of sulfonated 4H-3,1-benzoxazines has been accomplished by electrochemical radical cascade cyclizations of styrenyl amides with sulfonylhydrazines. This process demonstrates a wide substrate scope with diverse functional group compatibility under metal- and external oxidant-free conditions at ambient temperature.

A practical and efficient approach adopting transition-metal-free cross-coupling of sulfonyl hydrazides with benzyl ammonium salts has been developed to synthesize benzyl sulfones using Cs2CO3 as base under mild conditions. The protocol employs stable and easy to handle coupling partners, and is endowed with good substrate compatibility, leading to functional benzyl sulfones in good yields.

Sulfonyl hydrazides recently received much attention as reagents for the introduction of sulfur-containing functional groups into organic compounds, because both sulfonyl and sulfenyl sources could be generated by the oxidation and decomposition of the sulfonyl hydrazides, respectively. However, the transformations of sulfonyl hydrazides into thiosulfonates, which could be produced by the reaction between sulfonyl and sulfenyl sources, have been less investigated. In this manuscript, we describe CuCl2-promoted selective synthesis of thiosulfonates from sulfonyl hydrazides. A variety of thiosulfonates were produced in moderate to good yields. The mechanism involving radical intermediates such as sulfonyl radical and thiyl radical was proposed on the basis of the previously reported references and mechanistic investigations. In addition, quantum chemical simulations revealed that Cu-promoted decomposition of sulfonyl hydrazides is thermodynamically viable in the developed conditions.

An alternative metal-free, efficient and practical approach for the preparation of phosphinothioates is established via the aerobic oxidative cross-dehydrogenative coupling (CDC) of sulfonyl hydrazides with secondary phosphine oxides catalyzed by tetrabutylammonium iodide (TBAI) in the presence of atmospheric oxygen. The strategy provides an array of diverse phosphinothioates in good to excellent yields. Furthermore, two representative bioactive molecules are synthesized on up to gram scale by utilizing this method.

The reaction of arylsulfonyl hydrazides with tertiary amines provided β-amidovinyl sulfones in good yields under mild electrochemical conditions. The reactions were carried out using an acid, in a solution of nBu4NBF4 in dimethyl sulfoxide in undivided cells with graphite-platinum electrodes under a constant current. The arylsulfonyl hydrazides and tertiary amines were activated via a radical process by electrochemical oxidation and reacted to give the desired β-amidovinyl sulfones.

An alkyne difunctionalization cascade reaction was developed to generate α-sulfonylethanone oximes under metal-free conditions. The reaction features environmentally benign EtOH/H2O as a solvent, a broad substrate scope and easily scaled up for gram-scale synthesis. The reaction mechanism was illustrated with UPLC, GC-MS and UPLC-tof/MS.

An iodine (I2)/tert-butyl hydroperoxide (TBHP)-mediated annulation cascade between yne-allenones and sulfonyl hydrazides has been established, in which a wide set of dihydrobenzo[f]phthalazines were synthesized through one-pot, two-step strategy under metal-free conditions. The synthetic utility of these transformations leads to subsequent C?C and C?N bond-forming reactions to effectively build up functional aza-heterocycle with potential significance. (Figure presented.).

The first example of electrochemical deoxygenative C2 arylation of quinoline N-oxides using sulfonyl hydrazines was demonstrated in this work. By employing both anodic oxidation and cathodic reduction, a variety of 2-arylquinolines were synthesized under metal catalyst-, exogenous-oxidant-, and exogenous-reductant-free conditions.

An efficient method for the synthesis of (E)-β-aryl sulfonyl acrylates has been reported. This palladium-catalyzed approach showed excellent regio- and stereoselectivity in the sulfonylation of aryl propiolates with sulfonyl hydrazides. Through this approach, a wide range of (E)-β-aryl sulfonyl acrylates were obtained in moderate to high yields. (Figure presented.).

Background: Breast cancer is the most frequent cancer among women. Chemotherapy is necessary for treating metastatic disease and represents an important therapeutic approach, although antineoplastic drugs have high toxicity and may be limited by the development of drug resistance. These problems impose an urgent need to discover new anticancer agents and, so, arylsulfonylhydrazone analogues were designed, synthesized, and evaluated with regard to their cytotoxic activity against breast cancer cells in order to identify novel potential antitumor agents. Methods: Synthesis was performed as previously described by Fernandes and co-workers. Cytotoxicity of sulfonylhydrazones against MDA-MB-231, MCF-7 and 3T3 cells was evaluated by MTT method. Apoptotic effects was verified by Annexin-V/PI assay, Hoechst stain and propidium iodide stain. Molecular modeling was executed using Spartan’10 version 1.1.0. Geometry optimization was performed by the MMFF, PM6 and Hartree-Fock 3-31G* methods and electronic and lipophilic properties were computed. Results: Thirteen analogues were synthesized, which 3f and 4f were cytotoxic against evaluated breast cancer cells. The most promising compound, 3f, showed IC50 values equal to 104.6 and 142.4 μM for MDA-MB-231 and MCF-7, respectively. 3f induced apoptosis, causing phosphatidylserine externalization, pyknosis, and cell cycle arrest in the G0/G1 phase in MDA-MB-231 breast cancer cells. Furthermore, 3f was selective for tumor cells when compared to 3T3 fibroblasts. Structure-activity relationship suggests that introduction of a benzodioxol group increased cytotoxicity and superior lipophilicity may be related to superior activity. Conclusion: Sulfonylhydrazone analogues presented good activity against breast cancer cells by inducing apoptosis and might be a promising scaffold to further molecular modifications persuing more effective antitumoral agents.

A new pattern for difunctionalization of alkynes via a palladium-catalyzed regio- and stereoselective coupling-addition of propiolates with arylsulfonyl hydrazides is disclosed. The approach enables the synthesis of various highly functionalized (E)-vinylsulfones in satisfactory yields. Arylsulfonyl hydrazides act as both aryl and sulfonyl sources via selective cleavage of Ar(C)-S and S-N bonds, which are simultaneously incorporated onto the terminal carbon atom of an alkyne molecule.

An efficient copper-catalyzed radical cascade cyclization strategy was developed, by which a wide variety of 3-sulfonyl substituted indenones were prepared in one pot via reaction of 2-alkynylbenzonitriles with sulfonyl hydrazides in the presence of TBHP and CuI under mild reaction conditions. Much more importantly, the 3-sulfonyl indenones, synthesized through our newly developed copper-catalyzed radical cascade cyclization strategy, were found to own typical aggregation-induced emission (AIE) properties, showing orange to red emission with large Stokes shift (more than 135 nm). In addition, such newly found AIEgens could be successfully used in live cell imaging, exhibiting excellent biocompatibility and application potential.

Alzheimer's disease (AD) is the most common type of dementia and related to the degeneration of hippocampal cholinergic neurons, which dramatically affects cognitive ability. Acetylcholinesterase (AChE) inhibitors are employed as drugs for AD therapy. Three series of sulfonylhydrazone compounds were designed, and their ability to inhibit AChE was evaluated. Fifteen compounds were synthesized and twelve of them had IC50 values of 0.64–51.09 μM. The preliminary structure–activity relationships indicated that the methylcatechol moiety and arylsulfonyl substituents generated better compounds than both the benzodioxole and alkylsulfonyl chains. Molecular dynamics studies of compound 6d showed that the interaction with the peripheral binding site of AChE was similar to donepezil, which may explain its low IC50 (0.64 μM). Furthermore, the drug-likeness of 6d suggests that the compound may have appropriate oral absorption and brain penetration. Compound 6d also presented antiradical activity and was not cytotoxic to LL24 cells, suggesting that this compound might be considered safe. Our findings indicate that arylsulfonylhydrazones may be a promising scaffold for the design of new drug candidates for the treatment of AD.

A base-mediated bifunctionalization of alkenes for the synthesis of α-sulfonylethanone oximes was developed in water under metal-free conditions. This reaction features a wide substrate scope and facile starting materials to afford the desired products in high yields.

A palladium-catalyzed Sonogashira-type coupling between arylsulfonyl hydrazides and terminal alkynes via Ar(C)-S bond cleavage is disclosed, which enables the general synthesis of functionalized internal alkynes, especially the Br-substituted ones, in good to excellent yields under acid- and base-free conditions.

A novel catalyst-free sulfonation reaction for synthesizing 3-sulfone nitrile compounds from sulfonyl hydrazides and acrylonitriles in water, without any metal catalyst, ligand or organic solvent, was demonstrated. This catalyst-free protocol provides a new synthetic method for the construction of 3-sulfone nitrile compounds with excellent yields. The D2O experiment adequately proved that the catalyst-free sulfonation reaction occurs via a Michael addition mechanism and that the hydrogen of 3-sulfone nitrile comes from water.

An iodine-triggered dioxygen activation in oxysulfonylation reactions of unactivated olefins using sulfonyl hydrazides and iodine as catalyst is reported here. In one pot, near quantitative syntheses of β-hydroxysulfones were achieved at 70 °C, within 7 h, in acetonitrile and under aerobic conditions. A plausible mechanism is established by radical trapping and 18O labelling experiments for the operationally simple, efficient and economically viable transformation. The direct activation of aerial oxygen under metal-free and mild conditions is proposed for the oxysulfonylation of olefins. (Figure presented.).

A catalyst-free thiolation of indoles with sulfonyl hydrazides was efficiently developed in water under mild conditions without any ligand or additive. The reaction provided a variety of 3-sulfenylindoles with good to excellent yields and the only by-products were nitrogen and water.

A novel method to synthesise 2-arylindoles is demonstrated via direct arylation of indoles with arylsulfonyl hydrazides. Under the optimized reaction conditions, the reaction well tolerates a wide variety of functional groups to afford structurally diverse 2-arylindoles in good to excellent yields at 70 °C.

A Cu-catalyzed aerobic oxidative reaction between sulfonyl hydrazides and alcohols has been developed. In this reaction, sulfonyl hydrazides act as the sulfinic acid precursors to react with alcohols, resulting in sulfinic esters with up to 72 % yield. This catalytic system tolerates a wide range of sulfonyl hydrazide substrates, and represents a new strategy for the transformation of readily available sulfonyl hydrazides.

A catalyst-free sulfonylation reaction of activated alkenes with sulfonyl hydrazides was efficiently developed under mild and environmentally benign conditions, in water without any ligand or additive. The reaction gave a range of structurally diverse mono-substituted ethyl sulfones with excellent yields, in which the by-product was nitrogen. the Partner Organisations 2014.

1,1-Bis(trifluoromethyl)alkyl isocyanates obtained from perfluoroisobutene (PFIB) react with aroyl(arylsulfonyl)hydrazines. Twenty eight prospective biologically active polyfluorinated 1,4-substituted semicarbazides were synthesized. The structure of each

A palladium-catalyzed desulfitative-denitrogenative conjugate addition of arylsulfonyl hydrazides to α,β-unsaturated ketones is described. The reaction showed very good selectivity and tolerated a wide range of functionalities under an atmosphere of oxygen with or without the aid of a metal co-oxidant. The Royal Society of Chemistry 2013.

Palladium-catalyzed desulfitative and denitrogenative arylation of azoles with arylsulfonyl hydrazides has been achieved. A broad scope of azoles and arylsulfonyl hydrazides has been used to produce arylated azoles in high yields.

Members of a family of N-arylsulfonyl hydrazones have been identified as novel inhibitors of IMP-1, a metallo-β-lactamase of increasing prevalence. Structure-activity relationship studies have indicated a requirement for bulky aromatic substituents on each side of the sulfonyl hydrazone backbone for these compounds to serve as efficient inhibitors of IMP-1. Molecular modeling has provided insight into the structural basis for the anti-metallo-β-lactamase activity exhibited by this class of compounds.