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]2) 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. This Review summarizes the till date literature on its synthesis, characterization, and its catalytic role in various organic reactions.

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. SAR analysis was performed to explore comprehensive structure-activity relationships and a statistically reliable model to explain their antibacterial activities.

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.