Boyapati Manoranjan Choudary

Tungstate-exchanged Mg-Al-LDH catalyst: an eco-compatible route for the oxidation of sulfides in aqueous mediumIICT Communication No: 020222

The catalytic oxidation of sulfides selectively to sulfoxides and/or sulfones is realised for the first time with heterogeneous tungstate-exchanged Mg-Al-LDH catalyst using 30% hydrogen peroxide in aqueous media at a faster rate in quantitative yields at room temperature. The heterogeneous catalyst showed higher activity (TOF) over its homogeneous analogues and other heterogeneous catalysts reported so far. The catalyst is well characterised by various instrumental techniques such as FT-IR spectroscopy, thermal analysis (TGA and DTA), powder XRD and chemical analysis. The catalyst is reused for six cycles with consistent activity and selectivity.

The first example of heterogeneous oxidation of secondary amines by tungstate-exchanged Mg-Al layered double hydroxides: a green protocolIICT Communication No: 020213.

Tungstate exchanged Mg-Al layered double hydroxides a as recyclable heterogenised catalyst along with H2O2 as an oxidant for the oxidation of sec-amines to nitrones is developed for the first time, Reactions proceed at a fast rate in aqueous media in a single step at room temperature in good to excellent yields. The heterogenised catalyst showed higher activity (TOF) over their homogeneous analogues and other heterogeneous catalysts reported so far. The obtained catalysts were well characterised by various instrumental techniques such as FT-IR spectroscopy, thermal analysis (TGA and DTA), powder XRD and chemical analysis. The catalyst can be reused for six cycles with consistent activity and selectivity.

Mg-Al-O-But–Hydrotalcite:. a mild and ecofriendly catalyst for the cyanoethylation of alcohols and thiols†

Mg-Al-O-But–Hydrotalcite is found to be a mild and efficient catalyst for the cyanoethylation of alcohols and thiols in quantitative yields. Exclusive synthesis of 3-alkoxypropionitriles or 3-alkylmercaptopropionitriles is realised by compatible basic sites of Mg-Al-O-But–Hydrotalcite. The present ecofriendly catalytic system is a potential alternative to soluble bases.

Cyanosilylation of Aldehydes and Ketones Catalyzed by Nanocrystalline Magnesium Oxide

Abstract Cyanosilylation of various aldehydes and ketones with TMSCN proceeded smoothly under mild conditions to give the corresponding cyanohydrin trimethylsilyl ethers in the presence of nanocrystalline magnesium oxide. The cyanohydrin trimethylsilyl ethers of aldehydes produced cyanohydrins in good to high yields on treatment with 2 N HCl. 29Si NMR spectral evidence proved that the reaction proceeds through the hypervalent silicate species by coordination to O2−/O− (Lewis basic site) of nanocrystalline magnesium oxide.