A green synthesis of spirooxindole derivatives catalyzed by SiO2@g-C3N4 nanocomposite

Research on Chemical Intermediates - In this study, SiO2 nanoparticles were immobilized onto the surface of g-C3N4 nanosheets. The characterization of SiO2@g-C3N4 nanocomposite has been done by...     

AcOH catalyzed three-component synthesis of spirooxindole derivatives

An efficient one-pot synthesis of hereto unknown indenoquinoline-spirooxindole derivatives by a three-component reaction of isatins, indan-1,3-dione, and 3-aminocyclohex-2-enone under the catalysis of acetic acid was developed. The procedure had the advantages of simplicity and efficiency.     

An efficiently and quickly synthesized NiO@g-C3N4 nanocomposite-catalyzed green synthesis of spirooxindole derivatives

Research on Chemical Intermediates - NiO@g-C3N4 as an efficient catalyst for the synthesis of spirooxindole derivatives was prepared by impregnation of g-C3N4 with NiO nanoparticles and...     

A new strategy for the synthesis of 2-mercaptobenzazole derivatives by green chemistry metrics

Abstract

A green and efficient method has been developed for the synthesis of 2-mercaptobenzazole derivatives via the reaction of commercially available aniline derivatives with low-cost and nontoxic potassium thiocyanate in water. The reactions proceeded smoothly under catalyst- and ligand-free conditions to give the corresponding products in good to excellent yields. The versatility, low cost, and environmental friendliness, in combination with high yields and easy work-up makes the procedure noteworthy.     

An efficient approach for the synthesis of spirooxindole derivatives catalyzed by novel sulfated choline based heteropolyanion at room temperature

A new zwitterionic salt, sulfated choline based heteropolyanion, which was reported earlier by our group, has been found to be very effective for the synthesis of spirooxindole derivatives at room temperature. The heteropolyanion based on sulfated ionic liquid (HIL) showed promising features for the reaction, such as shorter reaction time, high product yields (about 90–95%), simple work up, easy removal, and reusability of the catalyst for several times without significant loss in its efficiency. This has made the protocol sustainable and economic.     

A green approach for synthesis of naphthoquinone-fused oxazine derivatives in water under ultrasonic irradiation

An efficient and eco-friendly procedure has been developed for synthesis of naphthoquinone-fused oxazine derivatives via one-pot pseudo four-component reaction of 2-hydroxy-1,4-naphthoquinone, aromatic amine and formaldehyde in water under ultrasound irradiation. This protocol has the advantages of being catalyst-free, with short reaction times and high yields, and being environmentally benign with an easy work-up.     

Highly efficient and green approach for the synthesis of spirooxindole derivatives in the presence of novel Brønsted acidic ionic liquids incorporated in UiO‐66 nanocages

An efficient and green approach is reported for the rapid synthesis of spirocyclic 2‐oxindole using triethylenediamine or imidazole Brønsted acidic ionic liquids supported in Zr metal–organic framework (TEDA/IMIZ‐BAIL@UiO‐66) as a novel, superior and retrievable heterogeneous catalyst under ultrasonic irradiation. Heterocyclic compounds including pyrido[2,3‐d:6,5‐d′]dipyrimidines and indeno[2′,1′:5,6]pyrido[2,3‐d]pyrimidines were obtained by the one‐pot condensation reaction of 6‐amino‐1,3‐dimethyluracil, isatins and cyclic 1,3‐diketone (barbituric acid or 1,3‐indanedione). The reusability of the catalyst, low catalyst loading, short reaction times, excellent yields, simple work‐up, and use of sonochemical procedure as a mild process and an alternative energy source are some of the advantages of this method. Furthermore, the novel heterogeneous nanocomposite was fully characterized using various techniques.     

Ionic liquid catalyzed one-pot multi-component synthesis of fused pyridine derivatives: A strategy for green and sustainable chemistry

The synthesis of a combinatorial library of heterocycle-fused pyridine derivatives has been achieved successfully via a one-pot four-component reaction of aromatic/aliphatic aldehyde, malononitrile, thiazolidine-2,4-dione and ammonium acetate in the presence of piperidinium acetate as the catalyst. It involved the Knoevenagel condensation of the aldehyde and malononitrile to produce arylidene malononitrile as an intermediate, which was further intramolecular cyclization through Michael type addition ketone to the electrophilic double bond of the arylidene to produce fused pyridines in high yields. Environmental friendliness, low cost, Operational simplicity, extensive reusability and applicability, and easy recovery of the catalyst using simple evaporation are the critical features of this methodology. Also, a series of pyridine based dihydrothiazolo[4,5-b] pyridine-6-carbonitrile analogs were synthesized and selected for their in vitro antifungal and antibacterial activities.     

A green method for the electroorganic synthesis of new 1,3-Indandione derivatives

This is an environmentally friendly method in the field of electroorganic reactions under controlled potential electrolysis, without toxic reagents at a carbon electrode in an undivided cell which involves the (EC) mechanism reaction and comprises two steps alternatively; (i) electrochemical oxidation and (ii) chemical reaction. In particular, the electrochemical oxidation of 4-tert-butylcatechol, 4-methylcatechol and 2,3-dihydroxybenzoic acid in the presence of 2-phenyl-1,3-indandione has been studied in a water-acetonitrile (90 : 10) mixture. The research includes the use of a variety of experimental techniques, such as cyclic voltammetry, controlled-potential electrolysis, and spectroscopic identification of products (FT-IR, (1)H-NMR, and MS spectrometry).     

Titanium-catalyzed stereoselective synthesis of spirooxindole oxazolines

A regio- and stereoselective cyclization between isatins and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (10 or 20 mol %) to afford spiro[3,3'-oxindoleoxazolines] in excellent yield (up to 99%) and diastereoselectivity (dr >99:1). Substitution at the 4-position of the oxazole controls nucleophilic attack to provide either the 2-oxazoline or 3-oxazoline spirocycle with excellent (>99:1) regiocontrol.     

A green method for the synthesis of thiochromene derivatives in ionic liquids

Controlling the pH value by changing the negative ion of ionic liquids, the same reactions of aromatic aldehyde, 2‐(2,3‐dihydrothiochromen‐4‐ylidene) malononitrile and malononitrile product unaromatized and aromatized 6H‐benzo[c]thiochromene derivatives in high yields. The nice features of these procedures include mild reactions condition, simple operations, high yields, and environmentally benign. J. Heterocyclic Chem., (2011).     

A convenient and mild one pot synthesis of cyclopentenone derivatives

Developed a convenient and mild one pot synthesis of cyclopentenone derivatives using 1-acetyl-1-cyclohexene and wide range of aldehydes. Aromatic and heterocyclic aldehydes with electron donating and withdrawing groups were conveniently converted to the corresponding cyclopentenone derivatives.     

One-pot synthesis of chalcone epoxides—A green chemistry strategy

Waste minimization is a very important aspect of an environmentally benign protocol. A one-pot consecutive process has been developed for chalcone epoxide synthesis that allows compounds to be prepared without having to isolate and purify the intermediates. The strategy utilizes consecutive Claisen Schmidt condensation and epoxidation reactions to prepare chalcone epoxides from substituted benzaldehydes and acetophenones in good yields.     

Piperidone synthesis using amino acid: A promising scope for green chemistry

Piperidone is a family of organic chemicals characterized by a 6-carbon ring substituted with nitrogen and a double-bonded oxygen atom. Piperidones are named by the location of the nitrogen or amine group on the ring. It differs from piperidine by the presence of oxygen molecule (from ketone). It is used in pharmaceutical companies and chemical manufacturers as intermediates having anti microbial activity. It is usually synthesized using ammonia both in laboratory and industry. In present study, amino acid namely aspartic acid is used instead of ammonia. The amino acid incorporated piperidones is purified and analyzed using NMR spectroscopy. It has antimicrobial activity against Pseudomonas aeruginosa and Salmonella aboni.     

Catalyst-free and solvent-free synthesis of novel symmetrical bisthioglycolic acid derivatives

A simple, efficient, eco-friendly, and cost-effective method has been developed for the synthesis of symmetrical bisthioglycolic acid derivatives by a one-pot reaction of aldehydes or ketones with thioglycolic acid under solvent- and catalyst-free conditions in excellent yields (87–97%). The advantages of this novel protocol include the excellent yields, operational simplicity, short reaction times, and the avoidance of the use of organic solvents and catalysts.     

金催化肌酸酐与靛红的加成反应:一种可持续的绿色方法用于非对映选择合成3-取代的3-羟基靛红

报道了水介质中金催化肌酸酐与不同靛红之间的醛醇缩合反应.该法无需繁杂的溶剂萃取和柱色谱技术,只需简单的过滤即可将产物分离出来,因而操作简单.通过较宽范围的靛红衍生物的反应,均可高产率并完全地制取相应的顺式醛醇缩合产物,因此该法表现出较高的通用性.还将该合成策略进一步拓展至靛红,肌酸酐和丙二腈的串联反应,可高产率、完全的制取反式多组分产物.采用分光光度法测定了合成产物的抗氧化性能,结果表明,与标准物相比,含有卤素原子的三个化合物(2c,2d和2e)表现出最高的活性.     

A mild high yielding synthesis of oxazole-4-carboxylate derivatives

Several 2,5-disubstituted oxazole-4-carboxylates were prepared in high yields from the methyl esters of N-acyl-β-halodehydroaminobutyric acid derivatives by treatment with a 2% solution of DBU in acetonitrile. The scope of this reaction was investigated and it was found that dehydrodipeptides having a β-bromodehydroaminobutyric acid residue gave the corresponding oxazoles in good yields. The photophysical properties of some of the oxazoles prepared were studied in four solvents of different polarity. All compounds have reasonable high fluorescence quantum yields and a moderate solvent sensitivity, which makes them good candidates to be used as fluorescent probes. One of the fluorescent oxazoles prepared was inserted after cleavage of the methyl ester into two model peptides using a conventional solution phase strategy. The photophysical properties of the labelled peptides were studied in ethanol and water and compared with those of the oxazole. The results obtained showed that the oxazole maintains a good fluorescence level and the same solvent sensitivity when linked to a peptide chain.     

Simple and efficient method for synthesis of metallodeutero-porphyrin derivatives bearing symmetrical disulphide bond

A novel thiol-derivative porphyrin[2,7,12,18-tetramethyl-13,17-di(3-disulfidepropyl)porphyrin]bearing the symmetrical disulphide bond and its metal complexes have been successfully prepared by means of modification on naturally easily derived heme.The results are described by MS-MS and UV-vis spectroscopy.     

Simple and efficient method for synthesis of metallodeutero-porphyrin derivatives bearing symmetrical disulphide bon

A novel thiol-derivative porphyrin [2,7,12,18-tetramethyl-13,17-di(3-disulfidepropyl)porphyrin] bearing the symmetrical disulphide bond and its metal complexes have been successfully prepared by means of modification on naturally easily derived heme.The results are described by MS-MS and UV-vis spectroscopy.