SummaryCuO-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.

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Zn[(L)proline] 2 was used as an efficient catalyst for the one-pot multicomponent reactions (MCR) of different aromatic amines, aromatic aldehyde and ketones in aqueous media. This method provides a novel and improved method for obtaining stereoselective β-amino carbonyl compounds in terms of good yield. Little catalyst loading, recyclability, easy accessibility of the catalyst and aqueous media are the main features of this protocol. Moreover column chromatography and recrystallization of product are not required as the crude product itself is very pure. Powder XRD and TEM images of the catalyst were taken for the first time.

SummaryThe N-acylation of ethanolamine (2) with various fatty acids 1a–d and esters of fatty acids 1e–h using Candida antarctica B lipase (Novozym® 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.

Abstract:The present investigation provides a simple and convenient route for the synthesis of substituted 5-deaza-10-oxaflavins owing to their importance as probable redox coenzymes. The reaction of a,b-unsaturated derivatives of barbituric acid and dimedone with catechol or 1,4-hydroquinones was catalyzed using laccase in aqueous medium. Quinones, generated in situ by the oxidation of the corresponding catechol or 1,4-hydroquinones, underwent a domino reaction with chalcones to produce 5-deaza-10-oxaflavins and tetrahydroxanthen-1-ones.