Concise synthesis of chiral 2(5H)-furanone derivatives possessing 1,2,3-triazole moiety via one-pot approach

Combining three bioactive units, such as 2(5H)-furanone, 1,2,3-triazole, and amino acid together into one potential drug molecule with polyfunctional groups, a series of new chiral 2(5H)-furanone derivatives containing 1,2,3-triazole moiety have been designed and synthesized from (5S)-5-alkoxy-3,4-dibromo-2(5H)-furanones, amino acids, propargyl bromide, and organic azides via the sequential three steps, including asymmetric Michael addition–elimination, substitution, and click reaction. The latter two steps, substitution and click reaction could proceed smoothly in a one-pot process. Furthermore, the target products could be directly synthesized via a four-component one-pot approach.     

CoFe2O4@SiO2-NH2-CoII NPs catalyzed Hantzsch reaction as an efficient,reusable catalyst for the facile,green, one-pot synthesis of novel functionalized 1,4-dihydropyridine derivatives

A magnetically heterogeneous CoFe₂O₄@SiO₂-NH₂-Co^II nanoparticle was synthesized by the immobilization of Co (II) complex onto CoFe₂O₄@SiO₂ nanoparticles, and the heterogeneous magnetic nanocatalyst was characterized by XRD, TEM, TGA, EDX, and FT-IR techniques. Then, the green and reusable method was introduced for a multicomponent synthesis of 1,4-dihydropyridine derivatives via Hantszch reaction. The synthesis of 1,4-dihydropyridine derivatives was proceeded by the reaction of aldehyde, ethyl acetoacetate, and ammonium acetate in the presence of this magnetic nanocatalyst in EtOH/Water (1:1). Simple work-up, short reaction times, excellent yields (60–96%) as well as green solvent are some advantages of this novel approach, and the corresponding products were purified with no need for chromatographic separation.     

Cu(I)-promoted one-pot synthesis of 1,4-disubstituted 1,2,3-triazoles from anti-3-aryl-2,3-dibromopropanoic acids and nitrobenzaldehydes

A series of 1,4-disubstituted 1,2,3-triazoles were synthesized through a one-pot process from easily available anti-3-aryl-2,3-dibromopropanoic acids and nitrobenzaldehydes in hexamethylphosphoric triamide. Inexpensive copper(I) iodide was the catalyst.     

Efficient method for the synthesis of 1,2,3-triazole functionalized isoxazolidine derivatives by 1,3-dipolar cycloaddition of nitrones with terminal olefins

1-Phenyl-1,2,3-triazole-4-carbaldehyde 1 was treated with different N-alkyl hydroxylamine hydrochlorides 2 using NaHCO₃ to obtain 1,2,3-triazole substituted N-alkyl nitrones 3a–c. The nitrones 3a–c were further reacted with different substituted olefins and furnished 2-alkyl-3-(1-phenyl-1H-1,2,3-triazol-4-yl)-5-(substituted)isoxazolidine derivatives 4a–p in high yields via 1,3-dipolar cycloaddition reaction.     

Design,synthesis, and antimicrobial activity of fluorophore 1,2,3-triazoles linked nicotinonitrile derivatives

The synthesis and investigation of fluorescence and antimicrobial properties of a new series of 1,2,3-triazoles were described. Acetylenes 4a–c were resulted via alkylation of 2-oxonicotinonitriles 3a–c with propargyl bromide in base medium. [2?+?3] cycloaddition of acetylenes 4a–c with ethyl 2-azidoacetate, p-acetylphenylazide, and p-tolylsulfonylazide in the presence of Cu(I) afforded 1,2,3-triazoles 5a–c, 7a–c, and 9, respectively (via click reaction). The triazoles 5a–c were subjected to saponification process to give the acids 6a–c. The fluorescence and antimicrobial properties of triazoles 5a–c, 7a–c, and 9 were investigated and significant results were obtained.     

Design,synthesis, and anticancer activity evaluation of novel aziridine-1,2,3-triazole hybrid derivatives

Some new 1-aryl-4-[(aziridine-1-yl)diaryl-methyl]-5-methyl-1H-1,2,3-triazole derivatives 7j–s were synthesized by the one-pot reaction of diaryl-(1-aryl-5-methyl-1H-1,2,3-triazol-4-yl)methanol compounds 6j–s formed from 1-aryl-5-methyl-1H-1,2,3-triazole-4-carboxylic acid derivatives. The new compounds 7j–s and 6j–s are investigated by ¹H and ¹³C NMR, MS, and IR. The anticancer activity of the synthesis target compounds was evaluated against human leukemia (HL-60) cells and human hepatoma G2 cells. Some of the compounds were highly efficient. The ¹H-NMR signals of the aziridine-ring cis-H/trans-H protons were found to be two group peaks at 1.800–1.884 and 1.183–1.327?ppm.     

Simple one-pot multicomponent approach to polyfunctionalized 2-amino-1-methyl-6-(methylthio)-5-nitro-4-aryl-1,4-dihydropyridine-3-carbonitriles

A series of polyfunctionalized 2-amino-1-methyl-6-(methylthio)-5-nitro-4-aryl-1,4-dihydropyridine-3-carbonitriles have been prepared using a multicomponent condensation reaction between aromatic aldehydes, malononitrile, and (Z) N-methyl-1-(methylthio)-2-nitroethenamine in the presence of Et₃N in acetonitrile.     

Catalytic synthesis of 1,4-dihydropyridine derivatives using scandium(III) triflate

Scandium(III) triflate smoothly catalyzed the reaction of imines with ethyl propiolate (2.5 equiv) to produce the corresponding N-substituted 1,4-dihydropyridines in good yields in toluene or BTF under reflux conditions. It also catalyzed the reaction of aniline and ethyl propiolate (3.2 equiv) to give another 1,4-dihydropyridine bearing three ester groups in moderate yield under the same conditions.     

Facile one-pot synthesis of new [1,2,4]triazolo[1,5-a]pyridine derivatives by ultrasonic irradiation

Herein, we report an ultrasonic promoted facile and convenient “one-pot” procedure for the synthesis of new [1,2,4]triazolo[1,5-a]pyridine derivatives 3, 4 and 5, using Amberlite IRA-400, in short reaction times and high yields and its comparison with classical reaction conditions. The structures of new compounds were assigned with the help of analytical ¹H, ¹³C NMR, and mass spectral studies.     

Recent advances in heterogeneous catalysts for the synthesis of imidazole derivatives

Among the bioactive heterocyclic frameworks, nitrogen containing multisubstituted imidazoles are versatile building blocks of many naturally occurring products. Imidazoles possess wide range of biological properties including anticancer, anti-inflammatory, antimicrobial, and antihypertensive activities with potential applications in other sectors. Multicomponent reactions in combination with heterogeneous catalysts and nanocomposites have contributed significantly to organic synthesis in general and imidazoles, in particular with high functional group tolerance. Owing to their tunable properties, lower operational cost, thermal stability, recyclability, and easily separation from products, heterogeneous catalysts and nanocomposites are integral part of numerous pharmaceutical, agrochemical, and industrial processes. There has been increased focus on the development of green and sustainable catalytic procedures for the building of novel and biologically potent imidazole conjugates. This article emphasizes the recent advances in recyclable catalysts and protocols, and their merits for the synthesis of diverse multisubstituted imidazole conjugates by one-pot reaction approach and the catalyst and reactant interactions.     

Controllable synthesis of bis(1,2,3-triazole)s and 5-alkynyl-triazoles via temperature effect on copper-catalyzed Huisgen cycloaddition

A facile synthetic protocol has been developed for the controllable preparation of bis(1,2,3-triazole)s and 5-alkynyl-1,2,3-triazoles from alkyne and azide under different temperatures. Various azides and alkynes were used as substrates for the reactions and the successful applications in nucleoside analogues manifested the values of this method in syntheses of bioactive molecules. Besides, a possible temperature-guided triazolyl–copper intermediate aerobic oxidative coupling mechanism was proposed for this controllable reaction procedure.     

Synthesis and mesomorphic behaviour of unsymmetrical tetracatenar [1,2,3]-triazole derivatives

New nonsymmetric four-chained and three-chained [1,2,3]-triazole derivatives were synthesised. Their phase behaviours were investigated by differential scanning calorimetry, polarised optical microscopy and X-ray diffraction analyses. The tetracatenar derivatives show a columnar mesophase and a lamellar crystalline phase. The effects of the length of the terminal alkoxy chain and the nature of the terminal group attached to the side phenyltriazole unit of the mesogenic core are discussed.     

One-pot two-step synthesis of fused thiazinofuranone linked geminal bis 1,2,3-triazole hybrids and their in vitro cytotoxic screening

In this study, a series of novel geminal bis 1,2,3-triazoles linked to 2H-furo[2,3-d][1,3]thiazine-2,4,5(1H,6H)-trione ( 3a-3m ) were prepared in one pot starting from 5-Acetyl-4-Hydroxy-1,3-thiazine-2,6-dione ( 1 ) to 6,6-diazido-2H-furo[2,3-d][1,3]thiazine-2,4,5(1H,6H)-trione ( 2 ) followed by Cu(I)-catalyzed azide-alkyne cycloaddition. The synthesized compounds were further explored for in vitro cytotoxic activity against PC3, A549, MCF-7, and HeLa cell lines and results revealed that the five compounds 3c , 3d , 3g , 3l , and 3m have displayed comparable in vitro cytotoxic activity with the standard drug Etoposide.     

Ultrasound-assisted,one-pot,three-component synthesis and antibacterial activities of novel indole derivatives containing 1,3,4-oxadiazole and 1,2,4-triazole moieties

Thirteen novel indole derivatives were efficiently synthesized through ultrasound irradiation by using 4-amino-5-(1H-indol-3-yl)-4H-[1,2,4]triazole-3-thiol (8) and 2-mercapto-5-substituted-1,3,4-oxadiazoles (5a–m). Compared with conventional and microwave methods, yields increased to 82–93%, and reaction times decreased to 15–35 min. The structures of these novel compounds were characterized by spectral data and elemental analysis. Two out of the synthesized compounds (10f and 10l) exhibited excellent activity against Staphylococcus aureus and Escherichia coli, and thus warrant further research.     

Synthesis and Antibacterial Activities of 1,4-Disubstituted Phenyl-5-(halo-2-hydroxyphenyl)imino-1,2,3-triazole

According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-(halo-2-hydroxyphenyl)imino-1,2,3-triazoles was synthesized and characterized by 1H NMR, ¹³C NMR, elemental analysis and IR. All the target compounds were screened for their antibacterial potential in vitro against Monilia albican, Escherichia coli and Staphylococcus aureus. It was shown that all the compounds possessed efficient antibacterial activities at a concentration of 0.1 mg/mL, even at a concentration of 0.01 mg/mL, some of the compounds still exhibited antibacterial activities against Escherichia coli and Monilia albican. At last, the structure- activity relationship was discussed based on the antibacterial results.     

Design,synthesis and antimicrobial activities of 1,2,3-triazole derivatives

Fifteen 1-(4-substituted phenyl)-4-(4-bromophenyl)-5-(halo-o-hydroxyphenyl)imino-1,2,3-triazoles were designed and synthesized based on rational combination of 1,2,3-triazoles and(halo)o-hydroxyphenyl group according to the superposition principle of reinforcement of biological activities.All the compounds were tested to an in vitro antimicrobial screening against M.a.and E.c..Compounds IIe-IIo exhibited more potent antimicrobial activities against M.a.and E.c.than triclosan and fluconazole,which provided valuable information to further study of novel antimicrobial research.     

Rapid and efficient one-pot synthesis of 1,4-dihydropyridine and polyhydroquinoline derivatives through the Hantzsch four component condensation by zinc oxide

A one-pot four-component reaction of aldehydes, ethyl acetoacetate/5,5-dimethyl-1,3-cyclohexanedione, ethyl acetoacetate and ammonium acetate in the presence of 10 mol% of ZnO as a heterogeneous catalyst for the synthesis of corresponding 1,4- dihydropyridine and polyhydroquinoline derivatives via the Hantzsch condensation is described. The present methodology offers several advantages such as simple procedure, excellent yields, and short reaction time.     

Practical one-pot synthesis of 5-alkynyl-1,2,3-triazoles via heterogeneous copper(I)-catalyzed tandem three-component click/alkynylation reaction

An efficient and practical route to 5-alkynyl-1,2,3-triazoles has been developed via heterogeneous tandem CuAAC/alkynylation reaction of organic azides, alkynes and 1-bromoalkynes by using an L-proline-functionalized MCM-41-anchored copper(I) complex [L-Proline-MCM-41-CuCl] as catalyst under mild conditions. The reaction produces a wide variety of 5-alkynyl-1,2,3-triazoles in mostly good to excellent yields. The new immobilized copper(I) complex can be readily prepared from commercially available and inexpensive reagents and displays the same catalytic activity as CuCl. The L-Proline-MCM-41-CuCl catalyst is also easy to recover via a simple filtration process and can be reused at least seven times without apparent loss of activity.     

Enantioselective synthesis of cyclic allylboronates by Mo-catalyzed asymmetric ring-closing metathesis (ARCM). A one-pot protocol for net catalytic enantioselective cross metathesis

Mo-catalyzed asymmetric ring-closing metathesis (ARCM) reactions are used to synthesize cyclic allylboronates of high optical purity (89% ee to >98% ee). A one-pot procedure involving formation of allylboronates, Mo-catalyzed ARCM and functionalization of the optically enriched cyclic allylboronates constitutes net asymmetric cross metathesis (ACM). Structural modification of ARCM products include reactions with aldehydes to afford optically enriched compounds that bear quaternary carbon centers with excellent diastereoselectivity. These studies emphasize the significance of the availability of chiral Mo-based complex as a class of chiral metathesis catalysts that frequently complement one another in terms of reactivity and selectivity.