Novel One‐Pot Three‐Component Reaction for the Synthesis of Functionalized Spiroquinazolinones

A wide variety of spiroquinazolinone derivatives have been synthesized via a one‐pot three‐component reaction of isatoic anhydride, cyclic ketones, and hydrazides in the presence of catalytic amount (20 mol%) of H₃PO₃ in ethanol. Mild reaction conditions, high atom economy, operational simplicity, and good to high yields are the key advantages of the present protocol.     

One‐Pot Three‐Component Synthesis of Highly Functionalized 2,3‐Dihydro‐1,3‐dioxo‐1H,5H‐pyrazolo[1,2‐a][1,2,4]triazoles

The reactive 1 : 1 zwitterionic intermediate formed by the addition of isocyanides to dialkyl acetylenedicarboxylates was trapped with 4‐arylurazoles to produce the highly functionalized pyrazolo[1,2‐a][1,2,4]triazoles 5 in good yields (Table). The structures of the products 5a – h were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR), by EI‐MS, and elemental analysis. A possible mechanism for this reaction is proposed (Scheme).     

One‐Pot Synthesis of Tetraalkyl Benzene‐1,2,3,5‐tetracarboxylates from a Four‐Component Reaction of Alkyl Propiolates and Alkyl 2‐Nitroethanoates Promoted by Ph3P

Alkyl 2‐nitroethanoates react with alkyl propiolates in the presence of triphenylphosphine (Ph₃P) in a mechanistically unprecedented reaction to afford tetraalkyl benzene‐1,2,3,5‐tetracarboxylates in moderate yields (36–42%).     

One‐Pot Three‐Component Synthesis of Hantzsch 1,4‐Dihydropyridines Promoted by Dimethyl Phosphate Ionic Liquids

A one‐pot three‐component reaction of ethyl acetoacetate, AcONH₄, and different aldehydes has been successfully performed in the presence of ionic liquids (ILs) possessing a (MeO)₂PO$\rm{{_{2}^{-}}}$ counterion. The impact of electronic and steric effects of the substituents of aromatic aldehydes, as well as the influence of different anions of ILs on the product yield, have been investigated. The application of dimethyl phosphate ILs in the synthesis of Hantzsch 1,4‐dihydropyridines presents a simple method for obtaining structurally diverse products in moderate to high yields without using any additional catalyst.     

One‐Pot Synthesis of Fused [1,6]Naphthyridine Derivatives via Three‐Component Reaction

A simple, convenient, and eco‐friendly synthetic protocol has been developed via a one‐pot three‐component reaction between 2‐chloroquinoline‐4‐amines, different substituted aromatic aldehydes, and malononitrile using ethanol as reaction medium. Employing this protocol, a series of 5‐chloro‐4‐phenyl benzo[f ][1,6] naphthyridine‐2‐amino‐3‐carbonitrile derivatives were synthesized in an environmentally friendly approach under operational simplicity, short time reactions, easy work‐up procedure, and comparatively high yields. This chemistry provides a convenient and promising synthetic strategy for the construction of the napthyridine skeleton. All synthesized compounds were identified on the basis of their spectral data.     

A Green Approach for the One‐Pot,Three‐Component Synthesis of 2‐Arylpyrroloacridin‐1(2H)‐Ones using Lactic Acid as a Bio‐based Catalyst under Solvent‐Free Conditions

A facile and benign synthetic strategy is proposed for the synthesis of 2‐arylpyrroloacridin‐1(2H )‐ones via a lactic acid‐catalyzed three‐component reaction of dimedone, various anilines, and isatins under solvent‐free conditions. Avoidance of hazardous organic solvents, the use of a one‐pot multicomponent procedure for the synthesis of 2‐arylpyrroloacridin‐1(2H )‐ones, operational simplicity, no need for column chromatography, lactic acid utilization as a bio‐based organic compound, reusability, homogeneity, and commercial availability of the catalyst, and superior synthetic performance are some important aspects of this methodology to access a series of pyrroloacridine motifs with potentially biological scaffolds.     

One‐Pot,Three‐Component Condensation of Aldehydes, 2‐Naphthol and 1,3‐Dicarbonyl Compounds

A practical and efficient procedure for the one‐pot multicomponent couping of aryl aldehydes, 2‐naphthol and cyclic 1,3‐dicarbonyl compounds using perchloric acid adsorbed on silica gel (HClO₄‐SiO₂) as a highly efficient, inexpensive, convenient, reusable heterogeneous catalyst under solvent‐free conditions has been developed. Various biologically important 12‐aryl‐8,9,10,12‐tetrahydrobenzo[a]xanthen‐11‐one derivatives have been efficiently synthesized in high to excellent yields. The present approach offers several advantages such as shorter reaction times, simple work‐up, excellent yields, low cost, and mild reaction conditions. Furthermore, the catalyst can be recovered simply and reused without appreciable loss of its catalytic activity.     

One‐Pot Synthesis of Functionalized (4‐Oxo‐1,3‐thiazinan‐5‐yl)acetic Acids from Isothiocyanates,Primary Alkylamines,and Ithaconic Anhydride

A one‐pot synthesis of 2‐(4‐oxo‐1,3‐thiazinan‐5‐yl)acetic acids is described via a three‐component reaction between primary alkylamines and ithaconic anhydride and phenyl isothiocyanate or benzoyl isothiocyanate.     

A Facile One‐Step Synthesis of 2‐Arylindazoles via Reductive Cyclization of N‐(2‐nitroarylidene)amines

A mild and efficient synthesis of 2‐arylindazole derivatives via the reductive cyclization of nitro‐aryl substrates mediated by a low‐valent titanium reagent (TiCl₄/Sm/Et₃N) has been developed. The attractive features of the current method include an N–N bond formation and the selective reduction of the C = N bond and nitro group, both of which were easily achieved in one‐pot by controlling the pH of the reaction mixture.     

One‐Pot Four‐Component Synthesis of Thieno[2,3‐d]pyrimidin‐4‐amines via Sequential Gewald/Cyclocondensation Reactions

A one‐pot four‐component synthesis of thieno[2,3‐d]pyrimidin‐4‐amines via sequential Gewald/cyclocondensation reactions is described. 2‐Aminothiophene‐3‐carbonitriles obtained from the Gewald reaction between cyclic ketones, malononitrile, and sulfur underwent a condensation? cyclization reaction with benzonitriles under solvent‐free conditions to afford the title compounds in excellent yields.     

One‐Pot Three‐Component Synthesis of α‐Amino Nitriles Catalyzed by 2,4,6‐Trichloro‐1,3,5‐triazine (Cyanuric Acid)

A simple and efficient method has been developed for the synthesis of α‐amino nitriles from aldehydes, amines and trimethylsilyl cyanide (Me₃SiCN) in the presence of a catalytic amount of cyanuric acid at room temperature.     

One‐Pot Synthesis of Pentaalkyl 7‐[(Alkylamino)carbonyl]‐2‐oxa‐1‐azabicyclo[3.2.0]hept‐3‐ene‐3,4,5,6,7‐pentacarboxylate

Dialkyl acetylenedicarboxylates react with alkyl 2‐nitroethanoates in the presence of alkyl isocyanides in a one‐pot reaction to afford the title compounds in 78–90% yield.     

A Simple One‐Pot Synthesis of N‐Alkyl‐2,5‐diaryl‐1,3‐dioxol‐4‐amines

An efficient procedure for the synthesis of N‐alkyl‐2,5‐diaryl‐1,3‐dioxol‐4‐amines 3 via a one‐pot reaction of aromatic aldehydes 2 and alkyl isocyanides 1 at room temperature in good yields is described (Scheme 1, Table).     

A Three‐Component One‐Pot Synthesis of Functionalized 5,5‐Dicyanocyclopenta‐1,3‐dienes from Arylidene­malononitriles,Activated Acetylenes,and KCN or KSCN

The reaction of dialkyl acetylenedicarboxylates with arylidenemalononitriles in the presence of KSCN in MeCN led to a mixture of dialkyl (3E)‐4‐aryl‐3‐(arylideneamino)‐5,5‐dicyanocyclopenta‐1,3‐diene‐1,2‐dicarboxylates and dialkyl 4‐aryl‐5‐cyanothiophene‐2,3‐dicarboxylates. When these reactions were performed in the presence of KCN, only the functionalized 5,5‐dicyanocyclopenta‐1,3‐dienes were obtained.     

Three‐Component One‐Pot Synthesis of Indeno[2′,1′:5,6]Pyrido[2,3‐d]Pyrazole Derivatives in Aqueous Media

A series of indeno[2′,1′:5,6]pyrido[2,3‐d]pyrazoles was synthesized by the three‐component reaction of aldehyde, 5‐amino‐3‐methyl‐1‐phenylpyrazole and 1,3‐indenedione in the presence of SDS in aqueous media. The structures were characterized by IR, ¹H NMR, high resolution mass spectra and were further confirmed by X‐ray diffraction analysis.     

Catalyst‐Free One‐Pot Synthesis of Ketene Imines under Ultrasound Irradiation

An efficient and simple procedure for the synthesis of ketene imines via a one‐pot three‐component reaction of cyclohexyl isocyanide, diethyl acetylenedicarboxylate, and 1,4‐dihydropyridines under ultrasonic irradiation is described. The remarkable advantages are the simplicity of the experimental procedures, high yields, and short reaction times.     

A Facile One‐Pot Synthesis of Functionalized 1,5‐Dihydro‐2H‐[1]benzopyrano[2,3‐b]pyridin‐5‐ones

The highly reactive 1 : 1 intermediate generated in the reaction between dialkyl acetylenedicarboxylate (=but‐2‐ynedioic acid dialkyl ester) 4 and triphenylphosphine was trapped by 2‐amino‐4‐oxo‐4H‐1‐benzopyran‐3‐carboxaldehydes 5 to yield highly functionalized dialkyl‐1,5‐dihydro‐5‐oxo‐1‐phenyl‐2H‐[1]benzopyrano[2,3‐b]pyridine‐2,3‐dicarboxylates in high yield.     

Synthesis of Novel α‐(Acyloxy)‐α‐(quinolin‐4‐yl)acetamides by a Three‐Component Reaction between an Isocyanide,Quinoline‐4‐carbaldehyde,and Arenecarboxylic Acids

Novel α‐(acyloxy)‐α‐(quinolin‐4‐yl)acetamides were synthesized by the Passerini three‐component reaction between an isocyanide, quinoline‐4‐carbaldehyde, and arenecarboxylic acids in H₂O. The reactions were carried out in one pot at room temperature with quantitative yields.