‘On water’ synthesis of 2,4-diaryl-2,3-dihydro-1,5-benzothiazepines catalysed by sodium dodecyl sulfate (SDS)

An efficient synthesis of 1,3-diaryl-2,3-dihydro-1,5-benzothiazepines has been developed by the reaction of various 1,3-diaryl-2-propenones with 2-aminothiophenol in water under neutral conditions catalysed by SDS. Excellent chemoselectivity was observed for substrates possessing halogen atoms or nitro/alkoxy/thioalkyl groups which did not undergo competitive aromatic nucleophilic substitution of the halogen atoms or the nitro group, reduction of the nitro or the α,β-unsaturated carbonyl group, or dealkylation of the alkoxy/thioalkoxy groups.     

Facile Synthesis of 1,5-Benzothiazepines in Water Using Tetrabutylammonium Tribromide

Abstract

A simple, environmentally benign, and efficient method was developed for the preparation of 1,5-benzothiazepines via a one-pot condensation reaction of 2-aminothiophenol with 1,3-diaryl- 2-propenones using tetrabutylammonium tribromide as an efficient and versatile catalyst in water.     

Fluoroboric acid adsorbed on silica-gel (HBF4-SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds

Fluoroboric acid adsorbed on silica-gel (HBF₄-SiO₂) has been found to be a new and highly efficient heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds under solvent-free conditions. In the case of 1,3-diaryl-2-propenones, the reactions are best carried out in MeOH. The rate of thia-Michael addition was dependent on the steric hindrance at the β-carbon of the α,β-unsaturated carbonyl substrate as well as surrounding the thiol moiety and was exploited for selective thia-Michael addition during intermolecular competition between two enones with a common thiol and between two aryl/alkyl thiols for a common enone. The methodology finds application for one-pot syntheses of 2,3-dihydro-1,5-benzothiazepines.     

Reaction between isocyanides and chalcones: an efficient solvent-free synthesis of 5-hydroxy-3,5-diaryl-1,5-dihydro-2H-pyrrol-2-ones

A simple and efficient synthesis of 5-hydroxy-3,5-diaryl-1,5-dihydro-2H-pyrrol-2-ones is described. Heating a mixture of an isocyanide and a 1,3-diaryl-2-propen-1-one under solvent-free conditions produces the title compounds in good to excellent yields.     

Synthesis of 1,3-Diaryl-2-methoxyindenes by Hydriodic Acid–Catalyzed Cyclization of Aryl[2-(1-aryl-2-methoxyvinyl)phenyl]methanols

An efficient two-step method for the synthesis of 1,3-diaryl-2-methoxyindenes from 1-(1-aryl-2-methoxyvinyl)-2-bromobenzenes has been developed. Thus, the reaction of 2-(1-aryl-2-methoxyvinyl)phenyllithiums, generated in situ by halogen–lithium exchange between 1-(1-aryl-2-methoxyvinyl)-2-bromobenzenes and butyllithium, with aromatic aldehydes gives aryl[2-(1-aryl-2-methoxyvinyl)phenyl]methanols, which in turn are treated with a catalytic amount of concentrated hydriodic acid to afford the corresponding 1,3-diaryl-2-methoxyindenes in reasonable yields.     

Ultrasonic-promoted three-component synthesis of some biologically active 1,2,5,6-tetrahydropyrimidines

Multicomponent reactions and organic synthesis with ultrasonic activation have been used as key methods for the synthesis of tetrahydropyrimidine derivatives. The three-component condensation of 1,3-diarylprop-2-en-1-one with ammonia and aldehydes/acetone or N-substituted gamma-pyridones under ultrasonic irradiation was developed as a rapid and efficient solution-phase method for the high-yielding preparation of 2-aryl(hetaryl)-4,6-diaryl-1,2,5,6-tetrahydropyrimidines and 2,4-diaryl-1,5,9-triazaspiro[5.5]undec-1-enes. The described synthetic protocol provides rapid access to novel and diversely substituted tetrahydropyrimidines libraries. The simple, primary biological screening showed 98% of inhibitory activity against Mycobacterium tuberculosis for one of tetrahydropyrimidines synthesized.     

A modular synthesis of unsymmetrical tetraarylazadipyrromethenes

[reaction: see text] A stepwise route to unsymmetrical tetraarylazadipyrromethenes by a condensation of 2,4-diaryl-5-nitroso-pyrroles with 2,4-diarylpyrroles is described. This modular building-block approach allows for the introduction of up to four different aryl substituents on the azadipyrromethene and is tolerant of a varied substituent set. An efficient synthesis of the 2,4-diarylpyrroles building blocks from 1,3-diaryl-4-nitro-butan-1-ones by nitro hydrolysis to a keto-aldehyde and subsequent ammonia condensation reaction has been achieved. The facile conversion of 2,4-diarylpyrroles into their alpha-nitroso analogues by their reaction with sodium nitrite generated the second building block required for the synthesis.     

CAN mediated decarboxylative hydroxylation/alkoxylation of N-aryl-γ-lactam-carboxylic acids at room temperature: an easy access to N-aryl-α-hydroxy/alkoxy-γ-lactams

An efficient and mild protocol for one-pot decarboxylative hydroxylation/alkoxylation of 1,3-diaryl-5-oxo-pyrrolidine-2-carboxylic acids to trans-5-hydroxy-1,4-diarylpyrrolidin-2-ones and 5-alkoxy-1,4-diaryl-1,5-dihydropyrrol-2-ones at room temperature using CAN in organo-aqueous solvent has been developed.     

New light on an old story: facile and efficient synthesis of 1,3-diaryl-5-spirohexahydropyrimidines via a six-molecule, three-component mannich-type reaction

A facile and efficient synthesis of 1,3-diaryl-5-spirohexahydropyrimidines via a one-pot condensation of anilines, formaldehyde, and cyclohexanones is reported. In this one-pot, three-component reaction, six molecules of reactants are involved and six new covalent bonds are generated. Bicyclic products are obtained from the starting materials in one pot using readily available starting materials and catalysts.     

Tetrahydrochromenylium and -Thiochromenylium Salts from Triketones of the 2-(3-Oxopropyl)cyclohexane-1,3-dione Series

We have worked out the optimal conditions for synthesis of 2,4-diaryl-5-oxo-5,6,7,8-tetrahydrochromenylium and -thiochromenylium salts based on triketones of the 2-(1,3-diaryl-3-oxopropyl)cyclohexane-1,3-dione series. For the first time, along with 5-oxo-substituted salts, we have obtained 5-thioxo-5,6,7,8-tetrahydrothiochromenylium salts. A necessary condition for the formation of the latter on treatment with acids and S-nucleophiles is the presence of electron-donor groups on the aryl substituents of the indicated triketones.     

Mercaptoacetic acid based expeditious synthesis of polyfunctionalised 1,3-thiazines

A novel three-component expeditious synthesis of 3,6-diaryl-5-mercaptoperhydro-2-thioxo-1,3-thiazin-5-ones from 2-methyl-2-phenyl-1,3-oxathiolan-5-one, an aromatic aldehyde and an N-aryldithiocarbamic acid is reported. The synthesis is diastereoselective and involves tandem Knoevenagel, Michael and ring transformation reactions under solvent-free microwave irradiation in a one-pot procedure.     

Synthesis,In Silico Studies,and Larvicidal Activity of Novel Hydrazinyl 1,3-Thiazine Derivatives

Russian Journal of Organic Chemistry - Looking at the importance of thiazine derivatives as biologically active compounds, herein we describe the synthesis of 4,6-diaryl-2-hydrazinyl-1,3-thiazines...     

Reaction of 1,3-diaryl-2,3-dibromo-1-propanones with urea in basic and acidic medium. Synthesis of pyrimidine,imidazoline and imidazolidine derivatives

Reaction of 1,3-diaryl-2,3-dibromo-1-propanones 1 with urea in basic medium afforded 4,6-diaryl-5-bromo-5,6-dihydropyrimidine-2(1H)-ones 4 . Oxidation of these bromopyrimidines 4 in dimethylsulphoxide gave 4,6-diaryl-1,6-dihydropyrimidine-2,5-diones 6 , which were further converted to their thione analogues 7 . Reaction of 1,3-diaryl-2,3-dibromo-1-propanones 1 with urea, phenylurea and sym-diphenylurea in glacial acetic acid medium gave in appreciable yields 4-phenyl-5-α-(bromoarylmethyl)imidazolin-2-one 8 and 1,3-diphenyl-4-aroyl-5-arylimidazolidin-2-one 11 respectively.     

Synthesis of conjugated (1E,3E)- and (1Z,3Z)-1,4-di(n-pyridyl) (or n-quinolyl)-1,3-butadienes from n-(2′-chloroethenyl)pyridine (or quinoline)

The homocoupling reaction between the conjugated n-(2-chloroethenyl)pyridine; n, 2-, 3- and 4- (or quinoline; n, 2- and 4-) mediated by zero-valent nickel complexes at room temperature affords to the corresponding 1,4-diaryl-1,3-butadiene, always as the 1E,3E stereoisomer. The yield in 1,4-diaryl-1,3-butadiene increases with the nickel catalyst and hence, the active zero-valent nickel catalyst is not regenerated during the homocoupling reaction.The stereospecific synthesis of (1Z,3Z)-1,4-di(4′-pyridyl)-1,3-butadiene stereoisomer was efficiently carried out by partial hydrogenation of the appropriate 1,4-di(4′-pyridyl)-1,3-butadiyne.     

Synthesis and photoluminescence properties of BF2 complexes with 1,3-diketone ligands

BF₂ complexes with 1,3-diketone ligands were synthesized, and their optical and electrochemical properties were studied. The colors of the complexes varied depending on the structures of the 1,3-diketone ligands. The absorption and emission maxima of the complexes with 1,3-diaryl-1,3-diketone ligands were considerably red shifted as compared to those of the complexes with 1-aryl-3-trifluoromethyl-1,3-diketone ligands, suggesting an extended π-conjugation of the 1,3-diaryl-1,3-diketone moieties. The molar absorption coefficients and quantum yields of the complexes with 1,3-diaryl-1,3-diketone ligands were larger than those of the complexes with 1-aryl-3-trifluoromethyl-1,3-diketone ligands. Cyclic voltammetry measurements revealed that the reduction potentials of the BF₂ complexes were higher than those of the free ligands. These complexes exhibited various emission colors in the solid states due to the intermolecular interactions.     

Reductive desymmetrization of 2-alkyl-1,3-diketones catalyzed by optically active beta-ketoiminato cobalt complexes

[reaction: see text] The reductive desymmetrization of acyclic 1,3-diketones was achieved for the first time by catalytic borohydride reduction in the presence of optically active beta-ketoiminato cobalt(II) complex catalysts. In this reaction, various 2-substituted-1,3-diaryl-1,3-propanediones were converted into the corresponding optically active 2-substituted-1,3-diaryl-3-hydroxypropanone in good-to-high yields with excellent diastereo- and enantioselectivities and high catalytic efficiencies.     

Dual Mechanism of Enamine-enamine Rearrangement of 1,3-diaryl-3-(1-imidazolyl)propen-2-ones

The formation of 1,3-diaryl-3-(1-imidazolyl)propen-1,3-diol that is an intermediate of enamine-enamine rearrangement of 1,3-diaryl-3-(1-imidazolyl)propen-1-ones constitutes the key stage of the dual mechanism of the rearrangement proper. The reaction of 1,3-diaryl-2,3-dibromopropan-1-ones with a primary amine provides 1,3-diaryl-3-iminopropan-1-ones as a result of enamine-imine prototropic rearrangement.     

New method for the annelation of a pyridine ring on derivatives of imidazole and benzimidazole

The interaction of (Z)-1,3-diaryl-4-bromo-2-buten-1-ones with 1-substituted (benz)imidazoles in benzene gave (Z)-1-R-3-(2,4-diaryl-4-oxo-2-butenyl)-1H-imidazolium bromides and (Z)-1-R-3-(2,4-diaryl-4-oxo-2-butenyl)-1H-benzimidazolium bromides which readily cyclize in the presence of base to form derivatives of 7,9-diarylpyrido[1,2-a]benzimidazole and 6,8-diarylpyrimidazo[1,2-a]pyridine. The effects of the nature of substituents in the benzene ring of the diarylbutenones and the substituent at N(1) in the (benz)imidazoles on the alkylation and cyclization reactions has been studied. The optimum conditions for the synthesis of the 5-R-4-hydroxy-2,4-diphenyl-4,5-dihydro-1H-pyrido[1,2-a]benz-imidazol-10-ium, 5-R-2,4-diaryl-4-hydroxy-4,5-dihydro-3H-pyrido[1,2-a]benzimidazol-10-ium, and 5-R-2,4-diaryl-5H-pyrido[1,2-a]benzimidazol-10-ium have been found.     

13C NMR spectra of some 1,2-disubstitutedN-vinyl-1H-1,2,4-triazoles

¹³C NMR spectra (20 and 75 MHz, in DMSO-d₆) of a series of 1,3-diaryl-3-(1H-1,2,4-triazol-1-yl)- and 1,3-diaryl-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones were registered. It was shown that the chemical shifts of both the carbon atom of the alkene group and C(3) reflect regio- and stereoisomerism of these compounds. Taking this into account the isomeric structures of several 1,3-diaryl-3-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones were identified and the configurations relative to the double bond of a number of 1,3-diaryl-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones were determined.     

Copper(I)-catalyzed reaction of diaryl buta-1,3-diynes with cyclic amines: an atom-economic approach to amino-substituted naphthalene derivatives

1,4-Diaryl-1,3-butadiynes react with cyclic amines, such as pyrrolidine, piperidine, and morpholine in the presence of a catalytic amount of CuCl to afford amino-substituted naphthalene derivatives with good to high yields. The new catalytic procedure provides an atom-economic, one-pot synthetic method for the synthesis of naphthalene derivatives from easily available 1,4-diaryl-1,3-butadiynes.