Bis[(l)prolinate-N,O]Zn: A water-soluble and recycle catalyst for various organic transformations.

Under the green chemistry perspective, bis[(l)prolinate-N,O]Zn (also called zinc-proline or Zn[(l)-pro]) has proven its competence as a promising alternative in a plethora of applications such as catalyst or promoter. Owing to its biodegradable and non-toxic nature of bis[(l)prolinate-N,O]Zn, it is being actively investigated as a water soluble green catalyst for synthetic chemistry. Bis[(l)prolinate-N,O]Zn are readily utilized under mild conditions and have high selectivity and reactivity with broad range of substrate acceptance to make it better reaction medium for a wide variety of organic transformations.

Ecofriendly approach for detection of phenols in water using laccase from different fungi.

Laccase-initiated oxidative coupling reactions of phenol and its derivatives with 4-aminoantipyrene using air as an oxidant has been investigated. The oxidation reaction of phenols and 4-aminoantipyrene is getting a lot of attention due to environmental concerns. Oxidation of simple phenol and 4-aminoantipyrene as a benchmark reaction enabled us to rank the relative oxidation ability of various laccases.

Magnetic nanoparticles catalyzed synthesis of diverse N-heterocycles.

A large library of diversified compounds (pyrano [2,3-d]pyrimidines, pyrido[2,3-d] pyrimidines and a variety of spirooxindoles) were synthesized through a very efficient, economical and environmentally benign process utilizing magnetic nanoparticles. Ease of recovery using an external magnetic field is an additional ecofriendly attribute of this catalytic system. Most of the compounds are new; therefore, could be further explored for their pharmaceutical application.

Synthesis of 2-oxo/thioxooctahydroquinazolin-5-one derivatives and their evaluation as anticancer agents.

An environment friendly method for the synthesis of 2-oxo/thioxooctahydroquinazolin-5-one derivatives has been devised using Ceric ammonium nitrate (CAN) as catalyst and polyethylene glycol (PEG) as solvent. The cytotoxic effect of these compounds was studied on U87 human glioma cells, compounds 4c, 4d and 4e are found to exhibit excellent activity at a concentration as low as 0.06 µg/ml.

Aqua mediated synthesis of 2-amino-6-benzothiazol-2-ylsulfanyl-chromenes and its in vitro study, explanation of the structure-activity relationships (SARs) as antibacterial agent.

Multi-component reaction (MCR) involves coupling of p-bromophenol with 2-Benzothiazolethiol, malononitrile and substituted aldehydes in aqueous K(2)CO(3) as green base to synthesize 2-amino-6-benzothiazol-2-ylsulfanyl-chromenes. This multi-component reaction thus offers a higher yield and versatility in the preparation of densely functionalized oxygen heterocycles. The newly synthesized compounds were screened for their antibacterial activities against positive and gram negative pathogenic strains to bacteria.

C-Arylation reactions catalyzed by CuO-nanoparticles under ligand free conditions.

CuO-nanoparticles were found to be an excellent heterogeneous catalyst for C-arylation of active methylene compounds using various aryl halides. The products were obtained in good to excellent yield. The catalyst can be recovered and reused for four cycles with almost no loss in activity.

N-acylation of ethanolamine using lipase: a chemoselective catalyst.

The N-acylation of ethanolamine (2) with various fatty acids 1a-d and esters of fatty acids 1e-h using Candida antarctica B lipase (Novozym((R)) 435) are described and optimum conditions for selective N-acylation rather than O-acylation are also discussed. Microwave assisted solution phase, solid supported and conventional methods were investigated and results were compared. There is a synergy between the enzyme catalysis and microwave irradiation.

Aqua mediated synthesis of substituted 2-amino-4H-chromenes and in vitro study as antibacterial agents.

A simple, clean, environmentally benign route to the synthesis of 2-amino-chromenes is described using K2CO3 as a green catalyst in water under microwave irradiation. This implies a convenient route avoiding the usage of hazardous organic solvents and organic bases. This technique requires only water in both the reaction step and workup, thus rendering the whole procedure into a truly ecofriendly green protocol.