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Developing the structures of organic materials that rely on the hydrogen bonding of multifunctional substrates is often complicated due to a competition between various possible motifs. In this context, the illustrative case of the carbamoylcyanonitrosomethanide anion, [ONC(CN)–C(O)NH2]−, suggests sufficient control over the crystal lattice with a set of supramolecular synthons, which are specific to all the present nitroso, carbamoyl and cyano groups. The structures of the carbamoylcyanonitrosomethanide salts of ethane-1,2-diammonium, C2H10N2 2+·2C3H2N3O2 −, (1), piperazine-1,4-diium, C4H12N2 2+·2C3H2N3O2 −, (2), butane-1,4-diammonium, C4H14N2 2+·2C3H2N3O2 −, (3), and hexane-1,6-diammonium, C6H18N2 2+·2C3H2N3O2 −, (4), reveal two- and three-dimensional hydrogen-bonded frameworks governed by a set of site-selective interactions. The strongest N—H...O hydrogen bonds [N...O = 2.6842 (17)–2.8718 (17) Å, mean 2.776 (2) Å] are associated with the polarized ammonium N—H donors and nitroso O-atom acceptors, which sustain invariant motifs in the form of nitroso/ammonium dimers. Subtle structural changes within this series of compounds concern the rupture of some weaker interactions, i.e. mutual hydrogen bonds of the carbamoyl groups in (1)–(3) [N...O = 2.910 (2)–2.9909 (18) Å; mean 2.950 (2) Å] and carbamoyl/nitrile hydrogen bonds in (1), (2) and (4) [N...N = 2.936 (2)–3.003 (3) Å, mean 2.977 (2) Å], providing a gradual evolution of the hydrogen-bonding pattern. A hierarchy of the synthons involving three different groups could be applicable to supramolecular synthesis with polyfunctional methanide species, suggesting also a degree of control over layered and interpenetrated hydrogen-bonded networks.

A preparative method for the synthesis of optically pure N-(1-phenylethyl)amides of inherently chiral (cR)- and (cS)-dibenzoyloxy-calix[4]arene acetic acids has been developed. Their absolute stereochemical configuration was determined by X-ray diffraction analysis.

The crystal structure of the title compound, [Ag2(VO2F2)2(C9H9N3)4], is presented. The molecular complex is based on the heterobimetallic AgI—VV fragment {AgI 2(VVO2F2)2(tr)4} supported by four 1,2,4-triazole ligands [4-benzyl-(4H-1,2,4-triazol-4-yl)]. The triazole functional group demonstrates homo- and heterometallic connectivity (Ag—Ag and Ag—V) of the metal centers through the [–NN–] double and single bridges, respectively. The vanadium atom possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N] with the Reedijk structural parameter τ = 0.59. In the crystal, C—H...O and C—H...F hydrogen bonds as well as C—H...π contacts are observed involving the organic ligands and the vanadium oxofluoride anions. A Hirshfeld surface analysis of the hydrogen-bonding interactions is also described.

A method for the synthesis of aminomethyl-substituted five-membered sultams has been developed. The aminomethyl sultams were synthesized from the corresponding iodomethyl derivatives by nucleophilic substitution of the iodine atom with sodium azide followed by reduction on Pd/C. This method was further expanded to side-chain-substituted sultams, starting from amino acid esters, to obtain aminomethyl-containing bicycles. The simple practical procedure and available starting amino acid esters, including chiral examples, make various bicyclic sultams readily available.

A 1,2,4-triazol-4-yl-acetic acid (trGly-H) was used for the synthesis of AgI and AgI/UVI coordination polymers. The composition space diagram was built for the AgNO3/trGly-H/UO2(NO3)2·6H2O system shows the crystallization fields of two AgI/UVI-compounds were found.

A regioselective method for the synthesis of 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-ones – close structural analogs of naturally occurring vasicinone alkaloids – is described. The procedure is based on PIFA-initiated oxidative 5-exo-trig cyclization of 2-(3-butenyl)quinazolin-4(3Н)-ones, in turn prepared by thermal cyclocondensation of the corresponding 2-(pent-4-enamido)benzamides. The products obtained have a good natural product likeness (NPL) score and therefore can be useful for the design of natural product-like compound libraries.

A preparatively convenient one-pot method for the synthesis of new 7-thioxo[1,3]thiazolo[3,2-c]pyrimidine derivatives 3a–3l by the cyclocondensation of 5-methyl(1,3-thiazolidin-2-ylidene)ketones 1a...

5-Chloro-4-formylpyrrole-3-carboxylates react with anilines or β-naphthylamine when heated in DMF under reflux to form ethyl pyrrolo[2,3-b]quinoline-3-carboxylates or their benzo[f] analogs, which exhibit moderate fluorescent properties. The corresponding carboxylic acids were obtained by alkaline hydrolysis of the synthesized carboxylates.

The work is devoted to the methods of synthesis of bis(polyfluoroalkenyl)sulfones and bis(polyfluoromethoxyalkenyl)sulfones as well as to the study of their reactions with diazomethane, resulting in the formation of N-methylated bis(pyrazolyl)sulfones isomers. Methods for the preparation of bis(polyfluoromethoxyalkenyl)sulfones not described previously in the literature have been developed by the addition of triethylamine and trimethylchlorosilane to a solution of the respective bis(polyfluoroalkyl)sulfones and methanol in diethyl ether in an argon atmosphere. A new method for the preparation of a previously unknown bis(3,3-difluoro-2,2-dimethoxypropyl)sulfone was suggested. The reaction occurs at room temperature in methanol in the presence of lithium hydroxide monohydrate. It was found that different regioisomeric bis(polyfluoroalkylpyrazolyl)sulfones are formed when using different methoxy derivatives of bis(polyfluoroalkenyl)sulfones in reaction with diazomethane, depending on the length of the polyfluoroalkyl moiety. These experimental data suggest that the attack of the double bond of methoxy-derived bis(polyfluoroalkenyl)sulfones by a molecule of diazomethane is influenced not only by the presence of an alkoxyl group, but also by the length of the polyfluoroalkyl substituent. The obtained bis(pyrazolyl)sulfones were investigated for the possibility of their use as ligands in the chemistry of metal complexes. It was shown that 5,5'-sulfonylbis[4-(difluoromethyl)-1-methyl-1H-pyrazole] forms a polymeric metal complex with silver nitrate. The results of X-ray structural analysis of the prepared coordination compound are presented. According to these results, the silver atom coordinates with two nitrogen atoms of pyrazole cycles of different molecules in the crystal of the obtained metal-complex compound, forming a supramolecular structure. In our opinion, an important role in this arrangement is played by the nitrate group that is coordinated with two silver atoms. As a result, we observed a supramolecular structure in the crystal that had a spiral structure with some free space in the middle. The paper also presents the results of spectral and X-ray diffraction analysis of a new regioisomeric compound of bis(3-hexafluoropropyl-1-methylpyrazolyl)sulfone.

The structure of the title salt, ammonium carbamoyl­cyano­nitro­somethanide, NH4 +·C3H2N3O2 −, features the co-existence of different hydrogen-bonding patterns, which are specific to each of the three functional groups (nitroso, carbamoyl and cyano) of the methanide anion. The relatively simple scheme of these inter­actions allows the delineation of the supra­molecular synthons, which may be applicable to crystal engineering of hydrogen-bonded solids containing polyfunctional methanide anions., The structure of the title salt, ammonium carbamoyl­cyano­nitro­somethanide, NH4 +·C3H2N3O2 −, features the co-existence of different hydrogen-bonding patterns, which are specific to each of the three functional groups (nitroso, carbamoyl and cyano) of the methanide anion. The nitroso O-atoms accept as many as three N—H⋯O bonds from the ammonium cations [N⋯O = 2.688 (3)–3.000 (3) Å] to form chains of fused rhombs [(NH4)(O)2]. The most prominent bonds of the carbamoyl groups are mutual and they yield 21 helices [N⋯O = 2.903 (2) Å], whereas the cyano N-atoms accept hydrogen bonds from sterically less accessible carbamoyl H-atoms [N⋯N = 3.004 (3) Å]. Two weaker NH4 +⋯O=C bonds [N⋯O = 3.021 (2), 3.017 (2) Å] complete the hydrogen-bonded environment of the carbamoyl groups. A Hirshfeld surface analysis indicates that the most important inter­actions are overwhelmingly O⋯H/H⋯O and N⋯H/H⋯N, in total accounting for 64.1% of the contacts for the individual anions. The relatively simple scheme of these inter­actions allows the delineation of the supra­molecular synthons, which may be applicable to crystal engineering of hydrogen-bonded solids containing polyfunctional methanide anions.

A preparatively convenient and efficient synthetic route to new 5H-[1,3]thiazolo[3,2-c]pyrimidine derivatives is described which involves the cyclocondensation of acyl or alkoxycarbonyl α-functionalized 2-methylidene-1,3-thiazolidin-4-ones with 1-chlorobenzyl isocyanates. The optimal reaction conditions, viz., heating reagents in toluene in the absence of an organic base, afford the target products in 48–74% yields. Some tert-butyl 2-(4-oxo-1,3-thiazolidin-2-ylidene)ethanoates produce, along with the desired tert-butyl [1,3] thiazolo[3,2-c]pyrimidine-8-carboxylates, the corresponding 8-carboxylic acids in 18–21% yields. A reliable structural determination of all the synthesized compounds has been performed by elemental analysis and a number of spectroscopic methods (1H and 13C NMR, HPLC/MS, and FT-IR) as well as by X-ray diffraction analysis.

All four possible stereoisomers of cis- and trans-2-bromo-2,3-dihydro-1H-inden-1-ols, which are important intermediates in the synthesis of biologically active compounds, were synthesized and their configurations were studied by enzymatic kinetic resolution with the application of the Kazlauskas rule, X-ray diffraction analysis, as well as NMR using NOE-NMR and Karplus equation. Biocatalytic kinetic trans-esterification was used for resolution of racemates. Lipases Burkholderia cepacia and Candida Antarctica B (Novozyme 435) were effective as biocatalysts for biocatalytic esterification of 2-bromo-2,3-dihydro-1H-inden-1-ols with isopropylidene acetate. The absolute configurations of (S,S)-, (R,R)-, (S,R)- and (R,S)-stereoisomers of 2-bromo-2,3-dihydro-1H-inden-1-ols were established.

The reaction of substituted 3,3-dichloroprop-2-enenitriles containing an N-methylurea or N,N-dimethylurea residue in the second position with secondary aliphatic amines gives rise to previously unknown 2,5-bis(alkylamino)-1,3-oxazole-4-carbonitriles. In the case of the reaction of N-(2,2-dichloro-1-cyanoethenyl)-N′-methylureas with benzylamines, 4,5-bis(alkylamino)-1-methyl-1H-imidazol-2(5H)-ones were obtained.

The convenient and scalable preparative approach for the two-step α-methylation of ketones is described. The optimized protocols for regioselective preparation of enaminones with further diastereoselective and functional groups tolerant hydrogenation to α-methylketones are developed. The scope and limitations of the proposed methodology are discussed. The advantages compared to known procedures are demonstrated. The unexpected role of acetone in the hydrogenation is suggested. The evaluation of the method for both early building block synthesis and late-stage CH-functionalization is shown. The elaborate procedures' preparability and scalability are demonstrated by the synthesis of several α-methyl ketones up to 100 g amount.

Cycloaddition reactions of 3,3,3-trifluoropropene derivatives containing an alkoxycarbonyl, sulfonyl, sulfoximine, or sulfamide substituent in position 1 with ethyl isocyanoacetate proceed with the formation of 3-(trifluoromethyl)-2,3-dihydro-1H-pyrroles, whereas their reactions with tosylmethyl isocyanide lead to the formation of 4-(trifluoromethyl)-1H-pyrroles.

A practical divergent synthetic approach is reported for the library of regio- and stereoisomers of glutamic acid analogs built on the spiro[3.3]heptane scaffold. Formation of the spirocyclic scaffold was achieved starting from a common precursor – an O-silylated 2-(hydroxymethyl)cyclobutanone derivative. Its olefination required using the titanium-based Tebbe protocol since the standard Wittig reaction did not work with this particular substrate. The construction of the second cyclobutane ring of the spirocyclic system was achieved through either subsequent dichloroketene addition or Meinwald oxirane rearrangement as the key synthetic steps, depending on the substitution patterns in the target compounds (1,6- or 1,5-, respectively). Further modified Strecker reaction of the resulting racemic spirocyclic ketones with the Ellman’s sulfinamide as a chiral auxiliary had low to moderate diastereoselectivity; nevertheless, all stereoisomers were isolated in pure form via chromatographic separation, and their absolute configuration was confirmed by X-ray crystallography. Members of the library were tested for the inhibitory activity against H. pylori glutamate racemase.

(5-Methyl-1,3-thiazolidin-2-ylidene) ketones, depending on the substituent in the ylidene part of the molecule, interact with tosyl azide to form (5,6-dihydro[1,3]thiazolo[3,2-c][1,2,3]triazol-3-yl) ketones and N-[(5,6-dihydro[1,3]thiazolo[3,2-c][1,2,3]triazol-3-yl)alkylidene]-tosylamides.

We found that 1-phosphanyl-1,2,3,4-tetrahydroquinazolines undergo ring enlargement. Their treatment with trifluoroacetic or hydrochloric acid afforded diazaphosphepinium salts. Deprotonation of the...

A method for the synthesis of iodomethyl-substituted five-membered sultams has been developed. The sultams were synthesized by intramolecular iodoamination of alkenyl sulfamides. The method allows synthesis of N- and C-substituted sultams. NH-Sultams were prepared by acidic cleavage of the corresponding tert-butyl sultams that are readily available. Varying the length of alkenyl substituent at sulfamide it was shown that only five- and six-membered sultams could be prepared by this method. Neither four- nor seven-membered sultams were detected. The simple practical procedure and available starting materials make the variously substituted sultams readily available.

Dichlorophosphoranides featuring N,N-dimethyl-N′-arylformamidine substituents were isolated as individual compounds. Dichlorophosphoranide 9 was prepared by the multicomponent reaction of C-trimethylsilyl-N,N-dimethyl-N′-phenylformamidine and N,N-dimethyl-N′-phenylformamidine with phosphorus trichloride. Its molecular structure derived from a single-crystal X-ray diffraction was compared to the analogous dibromophosphoranide prepared previously by us by the reaction of phosphorus tribromide with N,N-dimethyl-N′-phenylformamidine. It was shown that a chlorophosphine featuring two N,N-dimethyl-N′-mesitylformamidine substituents reacted with hydrogen chloride to form dichlorophosphoranide 11. Its molecular structure was also determined by X-ray analysis and compared with that of closely related dichlorophosphoranide C.

5-Substituted (1,3-thiazolidin-2-ylidene)ketones react regioselectively with 1-chlorobenzyl isocyanates under mild conditions to form diastereomeric 8-acyl-2,3,6,7-tetrahydro-5H-[1,3]thiazolo[3,2-c]pyrimidin-5-ones, the relative configuration of the chiral centers of which was determined by X-ray structural analysis.

The reactions of diazomethane with bis(2-fluoro-2-polyfluoroalkylalkenyl) sulfones are accompanied by dehydrofluorination and lead to the formation of new dipyrazolyl sulfones containing polyfluoroalkyl substituents at position 4 of the pyrazole ring. The structure of four new sulfones was confirmed by X-ray diffraction analysis.

Using DFT and ab initio calculations, we demonstrate that noncyclic formamidines can undergo thermal rearrangement into their isomeric aminocarbenes under rather mild conditions. We synthesized the silylformamidine, for which the lowest activation energy in this process was predicted. Experimental studies proved it to serve as a very reactive nucleophilic carbene. The reactions with acetylenes, benzenes, and trifluoromethane proceeded via insertion into sp, sp

The crystal structure of the title compound, [Ag