Gold(III) chloride catalyzed synthesis of chiral substituted 3-formyl furans from carbohydrates: application in the synthesis of 1,5-dicarbonyl derivatives and furo[3,2-c]pyridine.

This report describes a gold(III)-catalyzed efficient general route to densely substituted chiral 3-formyl furans under extremely mild conditions from suitably protected 5-(1-alkynyl)-2,3-dihydropyran-4-one using H2 O as a nucleophile. The reaction proceeds through the initial formation of an activated alkyne-gold(III) complex intermediate, followed by either a domino nucleophilic attack/anti-endo-dig cyclization, or the formation of a cyclic oxonium ion with subsequent attack by H2 O. To confirm the proposed mechanistic pathway, we employed MeOH as a nucleophile instead of H2 O to result in a substituted furo[3,2-c]pyran derivative, as anticipated.

Recent advances in polymeric electrospun nanofibers for drug delivery.

Electrospinning is a simple unit operation process by which polymeric nanofibers with diameters ranging from a few nanometers to hundreds of micrometers can be fabricated using an electrostatically operated jet of polymer solution or polymer melt. Nanofibers because of their interesting features, such as surface-to-volume ratio, high surface area, microporosity, and nonwoven structure, provide numerous opportunities to design novel carrier systems for large commodities of therapeutics. Physicochemical properties of nanofibers depend on several process and formulation parameters, such as applied voltage, flow rate, polymer selection, and concentration of polymer used.

PPh(3)·HBr-DMSO mediated expedient synthesis of γ-substituted β,γ-unsaturated α-ketomethylthioesters and α-bromo enals: application to the synthesis of 2-methylsulfanyl-3(2H)-furanones.

An efficient chemoselective general procedure for the synthesis of γ-substituted β,γ-unsaturated α-ketomethylthioesters from α,β-unsaturated ketones has been achieved through an unprecedented PPh3 ⋅HBr-DMSO mediated oxidative bromination and Kornblum oxidation sequence. The newly developed reagent system serves admirably for the synthesis of α-bromoenals from enals. Furthermore, AuCl3 -catalyzed efficient access to 3(2H)-furanones from the above intermediates under extremely mild conditions are described.