Ankita Rai

NHC-catalysed diastereoselective synthesis of multifunctionalised piperidines via cascade reaction of enals with azalactones.

NHC-catalysed azalactone ring-opening and piperidine ring-closing cascade with α,β-unsaturated aldehydes (enals) in a one-pot operation is reported. The present reaction cascade offers a convenient method for a highly diastereoselective synthesis of multifunctionalised piperidines in excellent yields under mild conditions.

A novel multicomponent synthesis of polyfunctionalized bicyclic tetrahydropyrimidinone derivatives via mercaptoacetylative ring transformations

A novel K-10 clay (nanoclay)-catalyzed expeditious synthesis of polyfunctionalized bicyclic pyrimidines using unprotected aldoses, 2-methyl-2-phenyl-1,3-oxathiolan-5-one and amidines/guanidine is reported. These polyfunctionalized bicyclic pyrimidines were obtained in excellent yields (72-93%) with high cis diastereoselectivity (>94%) at the ring junction via tandem condensation, mercaptoacetylative ring transformation and cyclization reactions. The process presents an excellent illustration of use of carbohydrates as renewable resources for the formation of pharmaceutically relevant fine chemicals employing solvent-free microwave irradiation conditions in a one-pot procedure.

Cu(OTf)2-catalysed synthesis of structurally novel bicyclic 1,3-oxazines via condensation-dehydrazinative ring transformation cascades

The Cu(OTf)2-catalysed expeditious synthesis of 1,3-oxazin-2-ones(thiones) from unprotected D-glucose and D-xylose in excellent yields is reported. Cu(OTf)2 plays a dual role of a Lewis acid and an oxidant for dehydrazination, which is the cornerstone in the present investigation. The 1,3-oxazin-2-ones(thiones) serve as synthons for diversity oriented synthesis of structurally distinct bicyclic 1,3-oxazin-2-ones(thiones), when subjected to Malaprade reaction, followed by Cu(OTf)2-catalysed cyclisation with an appropriate traditional reagent such as phenylhydrazine, amidines, hydroxylamine, or semi(thiosemi)carbazide.