Three‐Component One‐Pot Synthesis of 2,4,6‐Triarylpyridines without Catalyst and Solvent

An efficient and green synthesis of 2,4,6‐triarylpyridines by a one‐pot three‐component condensation of aromatic aldehydes, substituted acetophenones, and ammonium acetate without catalyst at 130°C under solvent‐free conditions is described. This method offers several advantages such as simple procedure, easy work‐up, short reaction time, low cost, environmentally friendly conditions, and moderate to high yields.     

Sustainable Catalytic Process with a High Eco‐scale Score for the Synthesis of Novel Series of Bischalcones through Claisen–Schmidt Condensation

An efficient, sustainable, and green method for the synthesis of novel series of bischalcones was developed using an environmentally benign ionic liquid as catalyst under ultrasound irradiation. This new catalyst affords diverse bis‐α, β‐unsaturated ketones in excellent yields under ambient reaction conditions in water. Moreover, the catalyst found to be active down to 15 mol% and affords the products with up to 96% yield. The process is eco‐sustainable since this ionic liquid is ease of recovery and reuse for at least five successive cycles without diminishing of the yield and catalyst leaching. Other merits of this protocol comprise its operational simplicity, short reaction time, non‐chromatographic purification procedure, and wide functional groups tolerance. Furthermore, this catalytic system is applicable for the gram‐scale preparation of bischalcones, scoring well in a number of green metrics.     

An Effective and New Method for the Synthesis of Polysubstituted Imidazoles by the Use of CrCl3.6H2O as a Green and Reusable Catalyst: Synthasis of Some Novel Imidazole Derivatives

New, efficient and environmentally adapted synthesis of polysubstituted imidazoles in one‐pot is found. The multicomponent reaction of various aldehydes, benzil, aliphatic and aromatic primary amines and ammonium acetate under solvent‐free condition is explained. The highly efficient role of CrCl₃.6H₂O as catalyst in this synthesis was shown. By this advantage, several polysubstituted imidazoles as pharmaceutical important molecules can be prepared in high yield and high purity. This method is a very easy and a rapid reaction for the synthesis of imidazole derivatives. The crude products recrystallized to afford the crystalline pure products. Furthermore, catalyst exhibited remarkable reusable activity.     

ZrOCl2·8H2O as an efficient and recyclable catalyst for the one‐pot multicomponent synthesis of novel [1,3]oxazino[5,6‐c]quinolin‐5‐one derivatives

A simple, efficient and eco‐friendly procedure has been developed using ZrOCl₂·8H₂O as catalyst for the synthesis of novel [1,3]oxazino[5,6‐c]quinolin‐5‐one derivatives in aqueous ethanol at room temperature. The present methodology offers several advantages such as operational simplicity, use of ZrOCl₂·8H₂O as a green, non‐toxic, inexpensive and reusable catalyst, reusability of reaction media, high yields, mild and environmentally benign reaction conditions.     

Three‐Component Uncatalyzed Eco‐Friendly Reactions for One‐Pot Synthesis of 4,7‐Dihydro[1,2,4]triazolo[1,5‐a]pyrimidine Derivatives

A three‐component system of one‐pot synthesis of [1,2,4]triazolo[1,5‐a]pyrimidine derivatives using condensation of 1,3‐dicarbonyl compounds, aldehydes, and 5‐amino[1,2,4]triazole in ethanol without any catalyst was reported in high yields via simple, efficient, and environmentally friendly process. The method reported herein considered a green process; this method has significant advantages of simple workup procedure, excellent yield, minimal environmental pollution, and short reaction time over classical reported methods.     

Catalyst-free,efficient and one pot protocol for synthesis of nitriles from aldehydes using glycerol as green solvent

We described herein the novel, efficient and one-pot catalyst free protocol for the synthesis of nitriles from aldehydes by using hydroxyl amine hydrochlorides in glycerol as a green solvent. This protocol was efficiently used for transformation of aromatic aldehydes bearing electron-withdrawing and electron-donating groups into a aryl nitriles in good to excellent yields. The methodology offers a very simple, efficient and environmentally benign procedure.     

A Quick and Clean Procedure for Synthesis of α‐Aminophosphonates in Aqueous Media

A green and efficient procedure for the synthesis of α‐aminophosphonates has been developed in water as a green and nonhazardous solvent, from condensation between aromatic aldehydes, aniline, and triphenyl phosphite at 80°C. This methodology has a number of advantages including clean reaction conditions, easy work‐up, and environmentally friendly.     

Clean,One‐Pot Synthesis of Naphthopyran Derivatives in Aqueous Media

A general and practical one‐pot synthesis of naphthopyran derivatives using hexadecyltrimethylammonium bromide (HTMAB) as catalyst (10 mol%) is described. This method provides several advantages such as neutral conditions, high yields and simple workup procedure. The catalyst is low cost, facile, active, environmentally friendly, and reusable. In addition, water is chosen as a green solvent.     

Water-acetic acid mediated an efficient one-pot eco-friendly synthesis of novel bis-isoxazolopyrroloquinoline derivatives

An efficient, cost-effective and environmentally benign synthesis of novel tetracyclic bis-isoxazolopyrroloquinoline derivatives has been developed via one-pot four-component reaction of 4-amino-3-methyl-5-styrylisoxazoles, dimedone, aryl glyoxal monohydrates and 5-amino-3-methylisoxazole by employing water as a reaction medium and acetic acid (AcOH) as a green promoter. The advantages of this protocol are environmentally friendly, metal-free, less reaction time, operational simplicity, high yields, broad substrate scope and easy purification. Most significant of all, this method is green.     

An efficient strategy for synthesis of 2,6‐dimethyl‐1,3‐diarylpyrano[4,3‐b]pyrrol‐4(1H)‐one derivatives in water

An efficient approach for the synthesis of 2,6‐dimethyl‐1,3‐diarylpyrano[4,3‐b]pyrrol‐4(1H)‐one derivatives has been established. The reaction was performed in aqueous media using readily available and inexpensive 6‐methyl‐4‐(phenylamino)‐2H‐pyran‐2‐one and nitroolefin as substrates. The present methodology shows many attractive advantages, such as using water as green reaction media, inexpensive and environmentally friendly acetic acid as catalyst, easy work‐up procedure, and good to excellent yields.     

Enzymatic Cascade Catalysis for the Synthesis of Multiblock and Ultrahigh‐Molecular‐Weight Polymers with Oxygen Tolerance

Synthesis of well‐defined multiblock and ultrahigh‐molecular‐weight (UHMW) polymers has been a perceived challenge for reversible‐deactivation radical polymerization (RDRP). An even more formidable task is to synthesize these extreme polymers in the presence of oxygen. A novel methodology involving enzymatic cascade catalysis is developed for the unprecedented synthesis of multiblock polymers in open vessels with direct exposure to air and UHMW polymers in closed vessels without prior degassing. The success of this methodology relies on the extraordinary deoxygenation capability of pyranose oxidase (P2Ox) and the mild yet efficient radical generation by horseradish peroxidase (HRP). The facile and green synthesis of multiblock and UHMW polymers using biorenewable enzymes under environmentally benign and scalable conditions provides a new pathway for developing advanced polymer materials.     

A Green and Highly Efficient Protocol for Catalyst‐free Knoevenagel Condensation and Michael Addition of Aromatic Aldehydes with 1,3‐Cyclic Diketones in PEG‐400

A convenient, highly efficient and green approach for synthesis of tetraketones from aromatic aldehydes with dimedone and 1,3‐indanedione at room temperature in PEG‐400 is described. The use of PEG‐400 as the reaction medium and avoiding the use of any catalyst makes the process environmentally benign. Seven new compounds are reported.     

o-Iodoxy Benzoic Acid–Mediated Synthesis of 3,5-Diarylisoxazoles and Isoxazole-3-carboxylic Acids

A new, convenient, ecofriendly synthesis of 3,5-diarylisoxazoles is reported from α,β-unsaturated ketoximes. Similarly, a novel synthesis of isoxazole carboxylic acids is also reported. Both the methods use efficient, environmentally friendly, and nontoxic iodoxybenzoic acid (IBX) as an oxidative cyclizing reagent. Easy procedure, environmentally benign reaction conditions, and nontoxicity are advantages to the methodology.     

Solvent‐Free One Pot Synthesis of 2‐aryl/Heteroarylbenzothiazoles Using Hypervalent Iodine (III) Reagents

In this article, an efficient, environmentally benign, one‐pot and simple synthesis of 2‐aryl/heteroarylbenzothiazoles by the reaction of 2‐aminothiophenol and aryl/heteroaryl aldehydes mediated by hypervalent iodine (III) reagents under solvent‐free condition at room temperature is demonstrated. All the reactions were carried out by grinding the reactants (2‐aminothiophenol and aryl/heteroaryl aldehydes) with hypervalent iodine (III) reagents in a mortar with pestle. Phenyliodine bistrifluoroacetate act as an efficient oxidizing reagent in comparison to iodobenzene diacetate in term of reaction time but yields are comparative. The advantages of this protocol are the one‐step procedure, mild reaction conditions, high yields of the products, and no side reactions.     

Synthesis and characterization of sodium polyaspartate‐functionalized silica‐coated magnetite nanoparticles: A heterogeneous,reusable and magnetically separable catalyst for the solvent‐free synthesis of 2‐amino‐4H‐chromene derivatives

An efficient and facile method was used for the synthesis of sodium polyaspartate‐functionalized silica‐coated magnetite nanoparticles. The structure of this nanoparticle was characterized by scanning electron microscopies, X‐ray diffraction, energy‐dispersive X‐ray, Fourier transform infrared spectroscopies and vibrating sample magnetometry. Then, this compound was used as a reusable heterogeneous catalyst for green synthesis of 2‐amino‐4H‐chromene derivatives via one‐pot three‐component reactions. This novel material showed great catalytic performance and the reactions which were carried out by this catalyst showed good to excellent yields. Besides, the catalyst could easily be separated from the reaction mixture by using an external magnetic field and it was stable enough to reuse several times without any significant reduction in the yield of reactions. Eco‐friendliness, high purity of the desired products, short reaction time and easy workup procedure can be mentioned as the other advantages of this method.     

KAl(SO4)2.12H2O(Alum): An Efficient Catalyst for the Synthesis of Novel bis[spiro(quinazoline‐oxindole)] Derivatives Via One‐Pot Pseudo Five‐Component Reactions

An efficient and convenient protocol for the synthesis of novel bis[spiro(quinazoline‐oxindole)] derivatives by one‐pot pseudo five‐component condensation of two molecules of isatoic anhydride, two molecules of isatins, and diamines in high yields and very short reaction time is described. This green protocol was catalyzed by Alum as a non‐toxic, reusable, inexpensive, and easily available reagent.     

Tetrabutylammonium Fluoride (TBAF) Catalysed Synthesis of 2‐Arylbenzimidazole in Water under Ultrasound Irradiation

One‐pot multistep reactions involving a new environmentally friendly catalytic procedure have been developed for the synthesis of benzimidazole. The reaction of the substituted aldehyde with o‐phenylenediamine in water under ultrasonic irradiation at ambient temperature for appropriate time using 5 mol% of TBAF furnish the desired product in good to excellent yield. The process is green, mild, inexpensive, excellent chemo selectivity, and excellent yields are the main advantages of this procedure.     

A Simple and Environmentally Benign Synthetic Protocol of Indeno‐Fused Pyrido[2,3‐d]pyrimidines

An efficient and environmentally benign protocol for the synthesis of indeno [2ˊ,1ˊ:5,6] pyrido[2,3‐d ] pyrimidines has been developed. The synthesis of these pharmacologically important compounds can be achieved by the one‐pot three‐component condensation of 6‐amino‐1,3‐dimethyluracil, aromatic aldehydes, and 1,3‐indandione in ethanol without using catalyst and oxidizing agent. This protocol has the advantages of easier work‐up, milder reaction conditions, and an environmentally benign procedure compared with other methods.     

Solvent‐Free Stereoselective Synthesis of cis‐1‐Carbomethoxy‐2‐Aryl‐3,3‐Dicyanocyclopropanes by Grinding

Abstract

The novel route of high stereoselective synthesis of cis‐1‐carbomethoxy‐2‐aryl‐3,3‐dicyanocyclopropanes by grinding is described. This process is simple, efficient, and environmentally benign.     

An efficient one‐pot synthesis of 2‐aminopyrimidinomethylnaphtols under solvent‐free conditions

A novel one‐pot three‐component condensation reaction of an aldehyde, 2‐aminopyrimidine and 2‐naphthol to afford the corresponding 2‐aminopyrimidinomethylnaphtols in good yields. The remarkable features of this new procedure are high conversions, short reaction time, clean reaction profiles, and environmentally benign and simple work‐up procedures.