An efficient three-component synthesis of highly functionalized tetrahydroacenaphtho[1,2-b]indolone derivatives catalyzed by L-proline

An efficient and diastereoselective synthetic procedure for highly functionalized tetrahydroacenaphtho[1,2- \(b\) ]indolone derivatives was successfully developed by the three-component reaction of acenaphthequinone, enaminones, and barbituric acid in the presence of a catalytic amount of L-proline. This method has the advantages of convenient operation, excellent yields, mild reaction conditions, and environmental friendliness.     

Electro-organic synthesis of tetrahydroimidazo[1,2-a]pyridin-5(1H)-one via a multicomponent reaction

Molecular Diversity - Electro-synthesis through a one-pot three-component condensation of corresponding aldehydes, Meldrum’s acid, and 2-(nitromethylene)imidazolidine resulted in a series of...     

Cascade process for direct synthesis of indeno[1,2-b]furans and indeno[1,2-b]pyrroles from diketene and ninhydrin

Molecular Diversity - Novel and efficient multicomponent reactions (MCRs) involving diketene, ninhydrin (indane-1,2,3-trione) and one primary amine (3CR) or two different primary amines (4CR) were...     

Organocatalytic three-component cascade reaction for the synthesis of spiro[indeno[1,2-b]furan]-triones

New methods for the synthesis of spiro compounds containing dihydrofuran and coumarin moieties from 3-bromo-4-hydroxycoumarins as cyclic α-halo compound based on a pyridinium-ylide-assisted three-component tandem reaction is investigated. To the best of our knowledge, employing cyclic α-halo compounds for the synthesis of dihydrofuran-fused coumarin via a pyridinium ylide has not been reported yet.     

Ultrasonic assisted synthesis of imidazo[1,2-a]azine catalyzed by ZnO nanorods

ZnO nanorods have been successfully used as an efficient, economic, and reusable catalyst for the synthesis of imidazo[1,2-a]azine under ultrasonic irradiation. This procedure offers advantages in terms of higher yields, short reaction times and mild reaction conditions.     

New multicomponent approach for the synthesis of benzo[c]coumarin derivatives over MgO under solvent-free conditions

In this study, a three-component one-pot synthesis of select 5-amino-6-cyano-3-hydroxybenzo[c]coumarin compounds derived from salicylaldehydes, malononitrile, and ethyl acetoacetate is reported. The reaction is conducted on grinding over MgO at room temperature resulting in good yields.     

Combining click-multicomponent reaction: one-pot synthesis of triazolyl methoxy-phenyl indazolo[2,1-b]phthalazine-trione derivatives

[(1,2,3-Triazol-4-yl)methoxy-phenyl]-2H-indazolo[2,1-b]phthalazine-trione derivatives were synthesized in a simple and efficient method from the one-pot four-component condensation reaction of phthalhydrazide, aromatic propargyloxy aldehydes, active methylene compounds (dimedone and 1,3-cyclohexanedione), and azides in the presence of Cu(OAc)(2)/sodium ascorbate and p-toluenesulfonic acid as catalysts in good to excellent yields.     

An efficient solvent-free synthesis of 2-(alkylamino)-2-oxo-1-arylethyl-6,12-dioxo-6,12-dihydroindolo[1,2-b]isoquinoline-11-carboxylate derivatives via four-component reaction

Molecular Diversity - A one-pot approach for the synthesis of a new series of 2-(alkylamino)-2-oxo-1-arylethyl-6,12-dioxo-6,12-dihydroindolo[1,2-b]isoquinoline-11-carboxylate derivatives via a...     

A mild and efficient method for the synthesis of a new class of furo[3,2-c]chromenes in aqueous media

An efficient synthesis of 2-hydroxy-3-[2-oxo-2-phenylethylidene]-2-phenyl-2, 3-dihydro-4 H-furo[3, 2-c]chromene-4(2H)-one is described. This involves the reaction between dibenzoylacetylene and 4-hydroxycoumarine in the presence of NaH (10 mol %) in nearly quantitative yield. Treatment of this heterocyclic system with trimethyl chlorosilane in CHCl₃ leads quantitatively to 4-oxo-3-[2-oxo-2-phenylethylidene]-2-phenyl-3H, 4H-furo[3,2-c]chromene-1-ium chloride. Direct addition of nucleophiles, such as alcohols, amines or trialkyl phosphites to this salt in water as the solvent produces functionalized 2-phenyl-4H-furo[3,2-c] chromen derivatives in excellent yields.     

A facile three- and four-component procedure toward the synthesis of functionalized pyrano- and benzo[f]quinoxaline derivatives

A two-step procedure has been used to synthesize quinoxaline derivatives in the presence of a catalytic amount of triethylamine. Products can be separated from the reaction media by simple filtration. When EtOH was used as a solvent, the reaction proceeded via a three-component pathway, but in the presence of MeOH (as a solvent or in a 1-equivalent) the reaction proceeded via a four-component pathway.     

Ultrasonics in isocyanide-based multicomponent reactions: A new,efficient and fast method for the synthesis of fully substituted 1,3,4-oxadiazole derivatives under ultrasound irradiation

A fast and convenient approach to the synthesis of fully substituted 1,3,4-oxadiazoles via three-component reaction of aromatic carboxylic acids, acenaphthoquinone, and (N-isocyanimino)triphenylphosphorane under ultrasound irradiation is described. Furthermore, a series of compounds were synthesized and characterized by melting point, IR, NMR and MS. Utilization of easy reaction conditions, very high to excellent yields, and short reaction times makes this manipulation potentially very useful.     

Regioselective and stereoselective synthesis of epithiomethanoiminoindeno[1,2-b]furan-3-carbonitrile: heterocyclic [3.3.3]propellanes

Molecular Diversity - Synthesis of heteropropellanes in one step: the reaction between dicyanomethylene-1,3-indanedione (CNIND) and N-substituted-2-(2,4-dinitrophenyl)hydrazinecarbothioamides,...     

An efficient synthesis of 2,5-diketopiperazine derivatives by the Ugi four-center three-component reaction

A facile synthetic approach to 2,5-diketopiperazines 4 by the Ugi four-center three-component reaction using commercially available dipeptides as a bifunctional component, aldehydes, and isocyanides was described.     

An efficient synthesis of pyrido[2,3-d]pyrimidine derivatives and related compounds under ultrasound irradiation without catalyst

A series of pyrido[2,3-d]pyrimidine derivatives and related compounds were synthesized via the condensation reaction of an aldehyde, 2,6-diaminopyrimidine-4(3H)-one and either tetronic acid or 1,3-indanedione under ultrasonic irradiation without catalyst. This protocol has the advantages of higher yields, lower cost and convenient procedure.     

New approach for the synthesis of novel acenaphtho[1,2-b]furan-8-amines

A new approach for the preparation of new 9-(alkyl or aryl)acenaphtho[1,2-b]furan-8-(alky or aryl) amine derivatives has been reported by the catalyst-free one-pot cyclocondensation of (acenaphthylen-1-yloxy)trimethylsilane, alkyl and aryl aldehydes, and aryl and alky isocyanides in refluxing DMF.     

An efficient ultrasound-promoted method for the one-pot synthesis of 7,10,11,12-tetrahydrobenzo[c]acridin-8(9H)-one derivatives

A new, efficient and general method for preparation of 7,10,11,12-tetrahydrobenzo[c]acridin-8(9H)-one derivatives using ultrasound irradiation is reported. Under ultrasound, the reaction time is short, the yields are high and the reaction conditions are mild.     

An efficient diastereoselective synthesis of novel fused 5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-ones via one-pot three-component reaction

Molecular Diversity - Herein, a convenient and efficient synthesis of 7-benzoyl-6-(aryl)-6,7-dihydro-5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-one derivatives was achieved from the reaction of...     

Highly efficient synthesis of quinoxaline derivatives from 1,2-benzenediamine and $$\alpha $$-aminoxylated 1,3-dicarbonyl compounds

Simple and efficient synthetic procedures for the preparation of quinoxaline, pyrazine, pyridopyrazine, and benzoxazin-2-one derivatives were developed. The one-pot cascade process involves the acidic elimination of \(\alpha \)-aminoxylated dicarbonyl compounds to generate 1,2,3-tricarbonyl compounds and subsequent condensation with 1,4-N,N or -N,O dinucleophiles to afford quinoxaline, pyrazine, pyridopyrazine, and benzoxazin-2-one scaffolds. All the proposed processes do not need extra catalysts, dry solvents, or harsh reaction conditions.     

An efficient approach for the direct synthesis of lithium niobate powders

Lithium niobate powders from the raw powders of Li₂CO₃ and Nb₂O₅ are directly synthesized by a combustion method with urea as fuel. The synthesis parameters (e. g., the calcination temperature, calcination time, and urea-to-(Li₂CO₃ + Nb₂O₅) quantity ratio) are studied to reveal the optimized synthesis conditions for preparing high-quality lithium niobate powders. In our present work, it is found that a urea-to-(Li₂CO₃ + Nb₂O₅) ratio close to 3, calcination temperature at 550∼600 °C and reaction time around 2.5 h may lead to high-quality lithium niobate powders. The microstructure of synthesized powders is further studied; a possible mechanism of the involved reactions is also proposed.