B. V. Subba Reddy

Gold Nanoparticles Embedded in a Mesoporous Carbon Nitride Stabilizer for Highly Efficient Three-Component Coupling Reaction†

Support with triple function: Au nanoparticles with sizes of less than 7 nm were fabricated in the channels of a mesoporous carbon nitride (MCN) support, which acts as a stabilizing, size-controlling, and reducing agent (see picture; Au NPs in green). The embedded, well-dispersed Au nanopartides are a highly active, selective, and recyclable catalyst for the three-component coupling reaction of benzaldehyde, piperidine, and phenylacetylene for the synthesis of propargylamine.

Microwave-assisted efficient synthesis of dihydro pyrimidines: improved high yielding protocol for the Biginelli reaction

Dihydropyrimidines were synthesised in high yields by one-pot cyclocondensation reaction of aldehydes, aceto-acetates and urea using various acid catalysts like Amberlyst-15, Nafion-H, KSF clay and dry acetic acid under microwave irradiation.

Tandem Prins/Friedel–Crafts Cyclization for Stereoselective Synthesis of Heterotricyclic Systems

Homoallylic substrates such as (E)-6-arylhex-3-enyl alcohols, N-tosylamides, and thiols undergo smooth cross-coupling with various aldehydes in the presence of 10 mol % Sc(OTf)(3) and 30 mol % TsOH to afford the trans-fused hexahydro-1H-benzo[f]isochromenes, N-tosyloctahydrobenzo[f]isoquinolines, and hexahydro-1H-benzo[f]isothiochromenes, respectively. However, the cross-coupling of (Z)-olefins such as 6-arylhex-3-enyl alcohols, N-tosylamides, and thiols with aldehydes affords the corresponding hexahydro-1H-benzo[f]isochromenes, N-tosyloctahydrobenzo[f]isoquinolines, and hexahydro-1H-benzo[f]isothiochromenes with complete cis selectivity via intramolecular Prins-, aza-Prins-, and thia-Prins/Friedel-Crafts cyclizations, respectively. Though the Prins cyclization proceeds smoothly under the influence of Sc(OTf)(3), high conversions and enhanced reaction rates are achieved using a mixture of Sc(OTf)(3) and TsOH (1:3).

Iodine-catalyzed condensation of isatin with indoles: a facile synthesis of di(indolyl)indolin-2-ones and evaluation of their cytotoxicity.

Isatin reacts smoothly with indoles in the presence of a catalytic amount of molecular iodine under mild conditions to afford a novel class of di(indolyl)indolin-2-one derivatives in good yields. These molecules are found to possess a promising cytotoxicity against cancer cells only but not on normal cells.

Sc(OTf)3-catalyzed C-glycosidation of glycals: a facile synthesis of allyl glycosides, glycosyl cyanides and glycosyl azides ☆

The treatment of glycals with allyltrimethylsilane, trimethylsilyl cyanide and trimethylsilyl azide in the presence of catalytic amounts of Sc(OTf)3 gave the corresponding 2,3-unsaturated allyl glycosides, glycosyl cyanides and glycosyl azides in excellent yields with high α-selectivity.

Indium-mediated deoxygenation of amine-N-oxides in aqueous media

Several aromatic and aliphatic amine-N-oxides were deoxygenated to the corresponding amines in good to quantitative yield using indium metal in neutral aqueous media. Other functional groups such as alkenes, halides, esters, ethers, nitriles, amides and sulfones are unaffected under the present reaction conditions.

Cu(OTf)2-catalyzed synthesis of 2,3-disubstituted indoles and 2,4,5-trisubstituted pyrroles from α-diazoketones.

A novel method has been devised for the synthesis of 2,4,5-trisubstituted pyrrole derivatives through the coupling of α-diazoketones with β-enaminoketones and esters using 10 mol % of Cu(OTf)(2). A wide range of 2,3-disubstituted indole derivatives were also prepared from α-diazoketones and 2-aminoaryl or alkyl ketones. The synthetic versatility of this approach has been exemplified in the formal synthesis of homofascaplysin C.

Addition of pyrroles to electron deficient olefins employing InCl3

Pyrroles undergo conjugate addition with electron deficient olefins in the presence of a catalytic amount of indium trichloride at ambient temperature to afford the corresponding Michael adducts in excellent yields with high selectivity without polymerisation.

Montmorillonite clay catalyzed in situ Prins-type cyclisation reaction ☆

Homoallylic alcohols smoothly undergo cross-coupling reactions with aldehydes on the surface of montmorillonite clay to generate 4-hydroxy-2,6-disubstituted tetrahydropyrans in high yields with high diastereoselectivity.

First examples of C-arylation of aziridines catalyzed by indium triflate

Abstract Aziridines react smoothly with arenes in the presence of a catalytic amount of indium triflate at ambient temperature to afford the corresponding β-aryl amine derivatives in excellent yields with high regioselectivity.