The applicability of the Hoveyda-Grubbs-type human serum albumin (HSA) based artificial metalloenzyme (AlbRu) for arene synthesis via ring-closing metathesis is investigated. We demonstrate how the electronic structure of the substrate impacts activity in the ring-closing metathesis, as well as in the dehydration/ aromatization step. A series of precursors for carbo-and heteroarenes were synthesized, evaluated in reactions with a non-protein Hoveyda-Grubbs catalyst and compared with the activity of the AlbRu complex. The obtained data give valuable insights for the future design of synthetic prodrugs to make biologically active aromatic molecules in vivo.

The reactivity of mucochloric acid and its 5-substituted derivatives towards 2,2'-oxydiethanethiol was studied. A specific feature of the reaction of mucochloric acid with 2,2'-oxydiethanethiol carried out in the presence of triethylamine was revealed. Compared to previously studied reactions with aliphatic dithiols, minor products of the lactone ring degradation, possessing a propenal fragment, were also isolated in this reaction, along with a bis-thioether of the 2(5H)-furanone series. A series of novel bis-thioethers and thiols containing an unsaturated γ-lactone ring and a dithiol fragment were synthesized and characterized.

Nitrogen-containing heterocycles of 3-pyrrolin-2-one series are widely represented in natural and synthetic compounds, with a broad spectrum of pharmacological activity and considerable potential in medicinal and synthetic organic chemistry. In this communication, we report the previously unknown acid-catalyzed transformation of a N-substituted derivative of 3-pyrrolin-2-one that generates two types of heterocyclic moieties. The reflux of 1-benzyl-3-chloro-5-hydroxy-4-[(4-methylphenyl)sulfanyl]-1,5-dihydro-2H-pyrrol-2-one in toluene in the presence of catalytic amounts of H2SO4 resulted in the formation of a mixture of 1-benzyl-3-[(4-methylphenyl)sulfanyl]-1H-pyrrole-2,5-dione and 1-benzyl-7-methyl-1H-benzo[4,5]thieno[3,2-b]pyrrole-2,3-dione. The structures of four novel nitrogen-containing heterocycles were elucidated through IR, NMR spectroscopy and HRMS spectrometry. A new derivative of the fused tricyclic compounds, possessing benzo[b]thiophene and pyrrole-1,2-dione fragments, was also characterized by single-crystal X-ray diffraction.

Синтезированы новые оптически активные тиоэфиры и сульфоны на основе 2(5Н)-фуранона, 4-аминотиофенола и двух монотерпеновых спиртов – l-ментола и l-борнеола. Методом рентгеноструктурного анализа исследована кристаллическая структура двух оптически активных сульфонильных производных фуранонового ряда. В обоих кристаллах вещество представлено независимыми молекулами А и В, имеющими радикальные различия в конформациях и системе водородных связей. Показана продуктивность подхода детального рассмотрения всех стереохимических особенностей молекулы в кристалле по данным РСА с привлечением анализа поверхностей Хиршфельда.

Methods for the synthesis of novel heterocyclic compounds bearing an unsaturated γ-lactone ring and an (S)-naproxen moiety were developed. The O-acylation reactions of 3,4-dihalo-5-hydroxy-2(5H)-furanones with (S)-(+)-2-(6-methoxy-2-naphthyl)propionyl chloride in the presence of Et3N afforded optically active furanone derivatives bearing an (S)-naproxen moiety at the 5 position of the lactone ring. Optically active 4-arylsulfanyl derivatives of 2(5H)-furanone were obtained by the reaction of the isolated (R,S) stereoisomers of 3,4-dihalofuranones with aromatic thiols. A series of heterocycles were synthesized based on 5-alkoxy- and 5-haloahkoxy-2(5H)-furanones containing an (S)-naproxen moiety in the side chain of the hydroxyethylthio substituent on the carbon atom C(4) of the five-membered ring. The structures of three new heterocycles were determined by X-ray diffraction.

In order to reduce the impact of heavy metals on water systems, extraction methods are widely used. Thiamacrocycles are promising extractants for heavy metal cations due to their high affinity for these ions. Although a large number of non-functionalized thiamacrocyclic ligands have been synthesized, oxathiamacrocycles containing small rigid molecules have been less thoroughly studied. This work describes the synthesis and characterization of two novel 28- and 30-membered oxathiamacrocycles as [2+2] macrocyclization products obtained from the reaction of 5,5'-(ethane-1,2-diylbis(oxy))bis(3,4-dichlorofuran-2(5H)-one) with 2,2'-oxydiethanethiol and 1,2-phenylenedimethanethiol in the presence of Et3N. These multidonor sulfur-containing macrocycles represent interesting objects for studying their complexation and extraction properties.

An overview of the main scientific achievements of Russian universities in the field of organic chemistry over the period 2018–2023 is presented.

A series of optically active 5(S)-(l-bornyloxy)- and 5(S)-(l-menthyloxy)-2(5H)-furanones with an arylthio group at the C(4) position of the γ-lactone ring was synthesized and studied for its oxidation reactions with various reagents. Novel 2(5H)-furanone sulfoxides were obtained as mixtures of two diastereoisomers through the oxidation of arylthioethers with m-chloroperbenzoic acid (m-СРВА) or hydrogen peroxide in acetic acid. Individual stereoisomers of these sulfoxides were isolated using recrystallization and high-performance liquid chromatography (HPLC) and characterized by IR and NMR spectroscopy. The molecular structures of eight stereoisomerically pure compounds were confirmed by X-ray diffraction (XRD) analysis. The antibacterial activity of the novel sulfoxides against Staphylococcus aureus and Escherichia coli was assessed, with a number of compounds found to inhibit bacterial growth and biofilm formation in S. aureus.

The synthesis and characterization of previously unknown azides, iminophosphoranes and amines from commercially available mucochloric and mucobromic acids is reported. The reaction of 5-alkoxy-3,4-dihalo-2(5H)-furanones with sodium azide resulted in the regioselective formation of furanone 4-azidoderivatives. A series of novel iminophosphoranes was obtained from the reaction of corresponding azides with triphenylphosphine. Reduction of iminophosphoranes with stannous chloride dihydrate led to the heterocycles, possessing an amino group at the C4 carbon atom of the unsaturated γ-lactone ring.

The reactions of dialkylzinc reagents with ketones are scarcely studied. In this paper, we describe a previously unknown direct alkylation of substituted 2-acetylpyridine with diisopropyl zinc, which gave a corresponding novel alcohol with 82% yield.

The interaction of propane-1,3-dithiol with the chiral bis-thioether, which combines two 2(5H)-furanone moieties, bridged through their carbon atoms C(4) by the propane-1,3-dithiol fragment, in DMF in the presence of potassium hydroxide or cesium carbonate resulted in the formation of an optically active fused bicyclic sulfur heterocycle, possessing 1,4-dithiepine and unsaturated γ-lactone moieties. The studied reaction follows an unexpected pathway in a basic medium with the thiolate–thiolate exchange. The structure of the novel heterocycle of the 1,4-dithiepinofuranone series is characterized by single-crystal X-ray diffraction.

Allylboration of the 1,2,3-triazole and pyrazole aldehydes with triallylborane or 2,4-pentadienyl(dipropyl)borane under mild reaction conditions provides high yields of the corresponding novel homoallylic and dihomoallylic alcohols that can be used to modify the side chain in the triazole- or diazole-based molecules. Enantioselective allylboration of triazole aldehydes with (+)-B-allyldiisopinocampheylborane gave optically active R(+) homoallylic alcohols in good yields with 80–93

A case of spontaneous chirality generation was observed during a synthetic project studying the allylboration of 1,2,3-triazolic aldehydes. Here, we present computational studies supported by experimental findings targeting the elucidation of border conditions required for the observation of spontaneous chirality generation in the reaction of 1-Ar-1H-1,2,3-triazole-4-carbaldehydes 1a,b with triallylborane. Three possible sources of symmetry breaking were found computationally. Thus, dimerization of the initial reaction products, alcoholates 4a,b, gives dimers 5a,b (homochiral) and 6a,b (heterochiral). The latter were computed to be more stable thermodynamically, which can lead to amplification of the initial stochastic imbalance of the enantiomers of 4a,b via the reservoir mechanism. Furthermore, enantiomeric excess can be increased during the transfer of the second allylic group in the reaction of optically active boronates 4a,b with 1a,b, which was computed to be enantioselective due to the strong activating and stereoregulating properties of the 1,2,3-triazole group. In addition, reactions of borinic esters 8a,b, products of the previous reaction with triallylborane, recovered in each case two molecules of 4a,b of the same handedness, which can lead to additional chirality amplification. Experimentally, reactions of optically active alcohols (+)-R-2a,b with triallylborane provided chiral alcoholates 4a,b, which were reacted with equivalent amounts of corresponding aldehydes 1a,b. Unexpectedly, in two series of 10 experiments each, preferential formation of both enantiomers of the newly formed product was observed: seven times S and three times R in the case of 1a and six times S and four times R in the case of 1b.

The phenomenon of amplifying asymmetric autocatalysis (AAA) has recently been restricted to alkylation of several specific substrates with diisopropyl zinc (Soai reaction). Targeting the extension of the scope of this phenomenon, we studied the reaction of triazolic aldehydes with diisopropyl zinc. Experiments demonstrated a diversity of results for the dissipation of chirality, conserving the existent ee and spontaneous chirality generation. Computational analysis showed that depending on the level of oligomerization of the catalyst, one could expect amplification (monomeric catalyst) while maintaining the existing chirality (dimeric catalyst) or dissipation of chirality (tetrameric catalyst). These findings are promising for the elaboration of synthetic protocols controlling chirality generation. In addition, three optically active triazolic alcohols were characterized.

Candida albicans and Staphylococcus aureus are human pathogens that are able to form mixed biofilms on the surface of mucous membranes, implants and catheters. In biofilms, these pathogens have increased resistance to antimicrobials, leading to extreme difficulties in the treatment of mixed infections. The growing frequency of mixed infections caused by S. aureus and C. albicans requires either the development of new antimicrobials or the proposal of alternative approaches to increase the efficiency of conventional ones. Here, we show the antimicrobial, biofilm-preventing and biofilm-eradicating activity of 2(5H)-furanone derivative F131, containing an l-borneol fragment against S. aureus–C. albicans mixed biofilms. Furanone F131 is also capable of inhibiting the formation of monospecies and mixed biofilms by S. aureus and C. albicans. The minimal biofilm-prevention concentration (MBPC) of this compound was 8–16 μg/mL for S. aureus and C. albicans mono- and two-species biofilms. While the compound demonstrates slightly lower activity compared to conventional antimicrobials (gentamicin, amikacin, fluconazole, terbinafine and benzalkonium chloride), F131 also increases the antimicrobial activity of fluconazole–gentamicin and benzalkonium chloride against mixed biofilms of S. aureus–C. albicans, thus reducing MBPC of fluconazole–gentamicin by 4–16 times and benzalkonium chloride twofold. F131 does not affect the transcription of the MDR1, CDR1 and CDR2 genes, thus suggesting a low risk of micromycete resistance to this compound. Altogether, combined use of antibiotics with a F131 could be a promising option to reduce the concentration of fluconazole used in antiseptic compositions and reduce the toxic effect of benzalkonium chloride and gentamicin. This makes them an attractive starting point for the development of alternative antimicrobials for the treatment of skin infections caused by S. aureus–C. albicans mixed biofilms.

A previously unknown reduction of carbonyl compounds with dicyclopentylzinc is reported. Aldehydes react in mild conditions yielding corresponding primary alcohols and cyclopentene. Although cyclohexanone and acetophenone are inert to dicyclopentylzinc, a variety of heterocyclic ketones reacted readily, yielding reasonable to high yields of corresponding secondary alcohols. When the reaction was catalyzed with (–)-(1R,2S)-ephedrine, 3-acetylpyridine (10) resulted in a high yield of (S)-1-(pyridin-3-yl)ethanol (19) with >99% ee. 5-Acetyl-2-bromopyridine (11) also provided the corresponding optically active alcohol 20, albeit with a much lower optical yield. When 10% of 19 with 92% ee was used as an autocatalyst, 55% yield of the same compound was obtained, with 95% ee and 96% ee in two independent experiments. A three-stage reaction sequence starting from “no chirality” reaction yielded 19 with 6% ee. Thus, amplifying autocatalysis was detected in the reaction of ketone 10 with dicylopentylzinc.

Novel disulfinyl derivatives based on 3,4-dichloro-2(5H)-furanone, aliphatic dithiols, and monoterpene alcohols were synthesized. Chiral bis-thioethers in the molecules of which the dithiol fragment links two five-membered cycles at C4 atoms were obtained in the reactions of 5(S)-(l-menthyloxy)- and 5(S)-(l-bornyloxy)-2(5H)-furanones with ethane-1,2-dithiol and propane-1,3-dithiol in acetone in basic medium. The action of an excess of m-chloroperoxybenzoic acid (2.0–3.2 equiv.) on bis-thioethers led to the formation of the corresponding mono- and disulfoxides bearing l-menthol or l-borneol fragments at the 5th position of the lactone ring. The methods of column chromatography and fractional recrystallization were used for the isolation of individual products. The structure of the synthesized heterocycles was proved by IR and NMR spectroscopy, and their composition was confirmed by high-resolution mass spectrometry. The molecular structure of the three disulfoxides was characterized by X-ray diffraction analysis.

Over the past decades, 2(5H)-furanone derivatives have been extensively studied because of their promising ability to prevent the biofilm formation by various pathogenic bacteria. Here, we report the synthesis of a series of optically active sulfur-containing 2(5H)-furanone derivatives and characterize their biological activity. Novel thioethers were obtained by an interaction of stereochemically pure 5-(l)-menthyloxy- or 5-(l)-bornyloxy-2(5H)-furanones with aromatic thiols under basic conditions. Subsequent thioethers oxidation by an excess of hydrogen peroxide in acetic acid resulted in the formation of the corresponding chiral 2(5H)-furanone sulfones. The structure of synthesized compounds was confirmed by IR and NMR spectroscopy, HRMS, and single crystal X-ray diffraction. The leading compound, 26, possessing the sulfonyl group and l-borneol moiety, exhibited the prominent activity against Staphylococcus aureus and Bacillus subtilis with MICs of 8 μg/mL. Furthermore, at concentrations of 0.4–0.5 μg/mL, the sulfone 26 increased two-fold the efficacy of aminoglycosides gentamicin and amikacin against S. aureus. The treatment of the model-infected skin wound in the rat with a combination of gentamicin and sulfone 26 speeded up the bacterial decontamination and improved the healing of the wound. The presented results provide valuable new insights into the chemistry of 2(5H)-furanone derivatives and associated biological activities.

Methods for the synthesis of novel optically active bisthioethers and disulfones of the furan-2(5H)-one series were developed. Bisthioethers with the dithiol fragment links two γ-lactone rings at the C4 atoms were synthesized by the reaction of 5(S)-(l-menthyloxy)- and 5(S)-(l-bornyloxy)furan-2(5H)-ones with ethane-1,2-dithiol and propane-1,3-dithiol in the presence of triethylamine. Chiral disulfones with a monoterpene alcohol fragment in the 5 position of the γ-lactone ring were obtained by the oxidation of the dithio furanone derivatives with hydrogen peroxide in acetic acid. The structure of five novel sulfur-containing furanone derivatives was characterized by single crystal X-ray diffraction.