β-cyclodextrin sulfuric acid as a green lewis acid catalyst has been applied for the preparation of bis(indolyl)methanes, tris(indolyl)methanes and 3,3'-diindolyloxindole derivatives by the condensation of indoles with various carbonyl compounds in aqueous media with high to excellent yields.

Recently, dynamic approach has been applied to determine the steady state concentrations of multiple ionic species present in complex buffers at equilibrium. Here, we have used the dynamic approach to explicitly model the pH profiles of biologically relevant phosphate buffer and universal buffer (a mixture of three tri-protic acids such as citric acid, boric acid and phosphoric acid). The resul...

The regioselective gold-catalysed hydration of propargylic alcohols to β-hydroxy ketones can be achieved by diverting the gold-catalysed Meyer-Schuster rearrangement through the addition of a protic additive with a pKa of 7-9 such as p-nitrophenol, boric acid or a boronic acid. This provides an interesting alternative to an aldol reaction when combined with the straightforward addition of an al...

We provide here evidence that supports the occurrence of a biologically dormant form of selectin ligand carbohydrate, the sialyl 6-sulfo Lewis X containing modified sialic acid, in human leukocytes. The modification of sialic acid involves first de-N-acetylation of sialic acid moiety through ubiquitous de-N-acetylation/re-N-acetylation cycle, followed by the dehydrative cyclization of de-N-acet...

Earlier proposed a general approach using data mV/mL from a potentiometric titration is tested for the quantitative determination of mixtures of monoand poly-protic substances. The method is based on the treatment of the primary data with nonlinear regression procedure using commercial software which gives directly the analytical result. A general formula valid for every type of acid base titra...

AIM The purpose of this research was to use metabolomics to investigate the cystic phenotype in the Lewis polycystic kidney rat. METHODS Spot urine samples were collected from four male Lewis control and five male Lewis polycystic kidney rats aged 5 weeks, before kidney function was significantly impaired. Metabolites were extracted from urine and analysed using gas chromatography-mass spectr...

5-(Hydroxymethyl)furfural (HMF) and levulinic acid production from glucose in a cascade of reactions using a Lewis acid (CrCl3) catalyst together with a Brønsted acid (HCl) catalyst in aqueous media is investigated. It is shown that CrCl3 is an active Lewis acid catalyst in glucose isomerization to fructose, and the combined Lewis and Brønsted acid catalysts perform the isomerization and dehydr...

The halogenation of Lewis-acid/base-stabilised phosphanylboranes () and arsanylboranes () with CX4 (X=Cl, Br) leads selectively to the substitution of both protons at the pentel atom and the new compounds [(CO)5W(X2PBH2.NMe3)] (:X=Cl, :X=Br) and [(CO)5W(X2AsBH2.NMe3)] (:X=Cl, :X=Br), respectively, are obtained. The new products were comprehensively characterised by spectroscopic methods and by ...

An original multi-cooperative catalytic approach was developed by combining metal–ligand cooperation and Lewis acid activation.