Three-component Reaction of Aromatic Aldehyde,Malononitrile and Aliphatic Amine Leading to Different Pyridine Derivatives

The three-component reaction of aromatic aldehyde,malononitrile and aliphatic amine in a mixed solvent of methanol and water exhibited very interesting molecular diversity and gave the derivatives of polysubstituted N-methyldihydropyridines,2-dialkylaminopyridines and 2-methoxypyridines as main products according to the structure of aliphatic amines used.

Green and High Efficient Synthesis of 2-Aryl Benzimidazoles: Reaction of Arylidene Malononitrile and 1,2-Phenylenediamine Derivatives in Water or Solvent-Free Conditions

A fast, high efficiency and environmentally friendly procedure for the synthesis of 2-aryl benzim-idazole derivatives has been reported. Reaction between 1,2-phenylenediamine derivatives and arylidene malononitrile under aqueous media and also solvent-free conditions generates 2-aryl benzimidazole derivatives with a high yield.

Some New Heterocycles from the Reaction of 4-Carboxaldehyde-2-Phenyl-2H-1,2,3-Triazole Malononitrile

Reaction of 4-carboxaldehyde-2-phenyl-2H-1,2,3-triazole 1 with malononitrile in presence of piperidine afforded the triazolomalonitrile 2 which on treatment with hydrazine hydrate, gave 3-amino-5-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-1-H-pyrazole-4-carbonitrile 3 and with hydroxylamine, gave 5-amino-3-(2-phenyl-2H-1,2,3-triazol-4-yl)-2,3-dihydroisoxazole-4-carbonitrile 4, and with thiourea, gave?2,4-diamino-6-(2-phenyl-2H-1,2,3-triazol-4-yl)-6H-1,3-thiazine-5-carbonitrile 5. Similarly, reaction of 2 with ethanol amine, gave 2-amino-4-(2-phenyl-2H-1,2,3-triazol-4-yl)nicotinonitrile 6, and with thiosemicarbazide,?gave 4-amino-2-hydrazinyl-6-(2-phnyl-2H-1,2,3-triazol-4-yl)-6H-1,3-thiazine-carbonitrile?7. Similary reaction of 2 with cyclopentanone gave, 2-amino-4-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5,6,7-tetrahydrocyclopenta [6] pyran-3-carbonitrile 8. In addition, reaction of 1 with hydrazine hydrate, gave the 4 hydrazone which on treatment with another mole of 1 gave 10 and with 3-carboxaldehyde-1-phenyl-4,5-pyrazolinedione 4 phenylhydrazone gave compound 11.

Utilization of bromine azide to access vicinal-azidobromides from arylidene malononitrile

An efficient and facile approach for tetrachlorosilane as an in situ mediated transformation via a one-pot, synthesis of vicinal bromoazides through the generation of BrN3 from azidochlorosilane and N-bromosuccinimide in acetonitrile as solvent at ambient temperature is achieved. This catalytic process represents a highly regioselective and high yielding method for the synthesis of 1,2- bromoazides. Thiamine pyrophosphate （TPP） riboswitches regulate essential genes in bacteria by changing conformation upon binding intracellular TPP. Molecular docking studies are conducted to understand the orientation and the interaction of each synthesized molecules with TPP riboswitches, 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academv of Medical Sciences.

Convenient synthesis of hexasubstituted benzene derivatives via DABCO promoted domino reaction of arylidene malononitrile and dialkyl but-2-ynedioate

A convenient synthetic protocol for the hexasubstituted benzene derivatives was successfully developed by DABCO promoted domino reaction of arylidene malononitrile with two molecules of dialkyl but-2-ynedioates.The domino reaction resulted in tetraalkyl 6-cyano-[1,1'-biphenyl]-2,3,4,5-tetracarboxylates in good to high yields.This formal[2+2+2]cycloaddition was believed to proceed with sequential nucleophilic addition.Michael addition,annulation and aromatization processes.

Cinchona Alkaloid-catalyzed Asymmetric Direct Mannich Reaction of Malononitrile to Imine for Synthesis of β-Amino Malononitrile

The first direct asymmetric Mannich reaction of malononitrile to N-Boc-protected imines has been developed with cinchona alkaloid as catalyst. The procedure could tolerate a relatively wide range of substrates, and results in excellent yields and good enantioselectivities even in the presence of only 1 mol% of catalyst loading. The present work provides an easy access to β-amino malononitrile derivatives.

Visible-light-induced novel cyclization of 2-(2-(arylethynyl)benzylidene)-malononitrile derivatives with 2,6-di(tert-butyl)-4-methylphenol to bridged spirocyclic compounds

A green and highly efficient strategy for the preparation of bridged spirocyclic compounds via visible-light-induced cyclization of 2-(2-(arylethynyl)benzylidene)malononitrile derivatives with 2,6-di(tert-butyl)-4-methylphenol(BHT)at room temperature was developed.The photoinduced radical reactions generated the corresponding products in good yields under simple and mild reaction conditions.

Electro-oxidation of paracetamol in the presence of malononitrile:Application for green,efficient,none-catalyst,simple and one-pot electro-synthesis of new paracetamols

Electrochemical oxidation of paracetamol has been studied in the presence of malononitrile as a nucleophile in a phosphate buffer solution （0.15 tool/L, pH 7）, using cyclic voltammetric techniques. The results indicated that the N-acetyl-p-benzoquinone-imine derived from paracetamol participates in a 1,4-Michael-ts, pe addition reaction with the malononitrile to form the corresponding paracetamol derivatives （6a, 7a）. The present study has led to the development of a simple, green, non-catalyst and one-pot electrochemical method with high atom economy under mild conditions.

Guanidinium Lactate Ionic Liquid: An Efficient and Recycling Catalyst for Michael Addition Reaction

A facile and efficient 1, 4-conjungate addition（Michael addition） reaction of active methylene compounds to aft-unsaturated compounds, catalyzed by guanidinium lactate ionic liquid（IL9）, has been developed. A range of chalcones and nitroalkenes together with active methylene compounds have been converted smoothly to the corresponding products in high yields.

硅胶键合N-丙基哌嗪n-丙酸钠作为可循环使用催化剂催化4H-吡喃衍生物合成(英文)

Silica‐bonded N‐propylpiperazine sodium n‐propionate(SBPPSP) was found to act as an efficient solid base for the preparation of a series of 4H‐benzo[b]pyran derivatives. SBPPSP was used as a recyclable heterogeneous solid base catalyst for the synthesis of 3,4‐dihydropyrano[c]chromenes, 2‐amino‐4H‐pyrans, 1,4‐dihydropyrano[2,3‐c]pyrazoles, and 2‐amino‐4H‐benzo[e]‐chromenes via the condensation reaction of dimedone, ethyl acetoacetate, 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐ one, and α‐naphthol, respectively, with aromatic aldehydes and malononitrile in refluxing aqueous ethanol. The heterogeneous solid base showed similar efficiency when reused in consecutive reactions.

Preparation of Polyfunctionally Substituted Pyridine-2(1<i>H</i>)-Thione Derivatives as Precursors to Bicycles and Polycycles

Reaction of acetylacetone with 1 mole of dimethylformamide dimethyl acetal (DMFDMA) affords enamine 2a which reacts with cyanothioacetamide to give pyridinethione 3a. Pyridinethione 3a reacts with methyl iodide, halogenated compounds, aromatic aldehyde and malononitrile/elemental sulfur to yiled compounds 7-10 respectively. Reactions of thioether 7 in ethanolic K2CO3, 1 mole DMFDMA and 4-(dimethylamino)benzaldehyde give compounds 11, 13, 14 respectively. Enaminone 12 can be prepared by reaction of compound 11 with DMFDMA. We have demonstrated some reactions in order to show the potential usefulness of the prepared compounds for the preparation of new bipyridyl compounds 15, 16, 18, bicyclic compounds 17 and uncommon tricyclic compounds 20, 21, 22 and 23 respectively using DMFDMA.

Dimethylformamide Dimethyl Acetal (DMFDMA) in Heterocyclic Synthesis: Synthesis of Polysubstituted Pyridines, Pyrimidines, Pyridazine and Their Fused Derivatives

Reaction of N,N’-dimethylformamide dimethyl acetal (DMFDMA) with malononitrile dimer 8 (1:1) mole afforded 9 while, this reaction when carried out in (2:1) mole to give amidine 11 which can be used for the preparation of pyrimidine 13, amidine 14 and pyridine 19 when reacted with 4-nitroaniline, 4-methylaniline and alkoxide respectively. Malononitrile dimer reacted with diazonium chloride to give pyridazine 21, which can be reacted with DMFDMA, AcOH/HCl and cyanoacetamide to give pyridazine 22, 23 and pyrido[4,3-c] pyridazine 24 respectively. The latter reacted with DMFDMA to afford tricyclic compound 25.

Visible Light Induced Knoevenagel Condensation Catalyzed by Starfruit Juice of <i>Averrhoa carambola</i>

Aqueous starfruit juice catalyzed a simple and efficient Knoevenagel condensation of aromatic aldehydes with malononitrile has been developed under visible light. Products were obtained in yields up to 98% after short reaction times and they were isolated by simple filtration in pure crystallization states. The method is green and economically viable. A plausible mechanism for photochemical Knoevenagel condensation reaction catalyzed by starfruit juice was also predicted.

Redox-neutral ipso/ortho alkenylcyanation of(hetero)arylboronic acid enabled by 1,4-rhodium migration and fragmentation

A mild,chemoselective,redox-neutral ipso/ortho alkenylcyanation of arylboronic acids with homopropargylic malononitriles via 1,4-rhodium migration and fragmentation is reported.A variety of 2-vinyl arylnitriles are obtained in good yields(51examples,ava.69%yields)through this strategy,which is characterized by its broad substrate scope,great functional group tolerance,and mild conditions.Mechanism studies indicate that the fragmentation is temperature dependent.The primary asymmetric exploration for the non-fragmentation product already shows promising results.The separation of the two cyano groups of homopropargylic malononitriles results in the formation of aromatic nitrile and aliphatic nitrile in one molecule,which enables the further transformations of the products.

Solvent-free Knoevenagel Condensations over TiO2

A study involving the scope of substrates in the Knoevenagel reaction under SFC has been conducted. Reactivity trends favored formation of the condensation product using both electron deficient and rich aryl aldehydes. A recycling study confirmed that the reaction medium could be used multiple times affording, with each run, the desired condensation product in excess of 95% conversion.

A convenient one-pot synthesis of new chromeno[3,4-c]chromene and chromeno[3,4-c]pyridine derivatives in the presence of high surface area of magnesium oxide

In this investigation a new strategy involves the one-pot, three-component reaction of malononitrile, salycilaldehyde and phenol derivatives in the presence of high surface area of MgO is extended to the formation of chromeno[3,4-c]ehromene derivatives in good to excellent yields in a short reaction time. Also, the three component reactions of an aldehyde such as salycilaldehyde and ketones with malononitril for the formation of chromeno[3,4-c]pyridines are investigated.

Three-component reaction for synthesis of functionalized spiro[indoline-3,4'-pyrano[3,2-h]quinolines]

The functionalized spiro[indoline-3,40-pyrano[3,2-h]quinolines] were efficiently prepared in high yields from three-component reaction of 8-hydroxyquinoline, isatins and malononitrile or ethyl cyanoacetate in ethanol at room temperature for about 12 h in the presence of piperidine.

An environmentally friendly synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives catalyzed by tungstate sulfuric acid

An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile using tungstate sulfuric acid as a catalyst was described.Mild conditions,good to excellent yields,easily available catalyst and easy work-up are the key features of this method.

PTB7-Th based organic solar cell with a high V_(oc) of 1.05 V by modulating the LUMO energy level of benzotriazole-containing non-fullerene acceptor

The open-circuit voltage （Voc） of classical photovoltaic polymers, such as P3HT and PTB7-Th, are always restricted when combining with fullerene derivatives, due to the difficulty of modulating the energy levels of fullerene derivatives. Thus, design of new non-fullerene small molecule acceptor （NFSMA） is very significant to match with these mature polymer donors and improve the Voc and power conversion efficiency （PCE）. Here, a new benzotriazole （BTA）-based NFSMA, BTA7 was synthesized by adopting A2----A1--D--A1--A2 type molecular backbone. By using a strong electron-accepting unit of malononitrile （M） as terminal segment A2, BTA7 demonstrates strong crystallinity, red-shifted absorption spectrum and down-shifted lowest unoccupied molecular orbital （LUMO） energy levels in comparison with BTA1 and BTA2. Organic solar cells （OSCs） based on PTB7-Th：BTA7 realized a high Voc of 1.05 V with a moderate PCE of 4.60%. The energy loss （Eloss = Eg - eVoc） of 0.53 eV is lower than the experiential minimum value of 0.6 eV, which indicates PTB7-Th still has large potential to improve the Voc and photovoltaic performance after the development of novel electron acceptors.

Simple and Efficient Procedure for Highly Diastereoselective Synthesis of trans- 1,1-Disubstituted-2,6-diarylcyclohexane-4-ones

A simple and efficient method has been developed for highly diastcreoselective synthesis of trans-1,1-disubstituted-2,6-diarylcyclohexane-4-ones from dibenzalacetone and malononitril with trans-1,2-diaminocyclohexane as catalyst. The substrate 1,5-diaryl-1,4-pentadien-3-ones and active methylene compounds proceeded to give the products with good to excellent yield within a short time.