The reaction between phenothiazine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in the presence of p-toluenesulfonic acid in chloroform was investigated by potentiometry, voltammetry and spectrophotometry, and the reaction pathways were proposed. The conditions for the oxidimetric titration of phenothiazines with a standard chloroform solution of DDQ were optimized and the potentiometric...

A novel series of mesotetrakis[aryl]-21H,23H-porphyrin derivatives 2a-j was synthesized from the condensation of aldehyde derivatives 1a-j with pyrrole in the presence of p-toluenesulfonic acid. The synthesized porphyrins were considered as a model to study the free radical-induced damage of biological membranes and the protective effects of these porphyrins. It was found that these compounds e...

The hexanuclear metallacrown [Ni6L12] (L is mu-S-CH2-CH2-S-C6H4-Cl) has been demonstrated to functionally resemble the [NiFe] hydrogenases. Protonation of the [Ni6L12] cluster was studied employing 1H NMR spectroscopy by the sequential additions of dichloroacetic acid or p-toluenesulfonic acid monohydrate into solutions of [Ni6L12] in CD2Cl2 and DMF-d7, respectively; protonation takes place on ...

As a way to valorise glycerol, the main by-product of biodiesel, this study is focused on production esters p-methoxycinnamic acid and glycerol. These can replace hazardous octylmethoxycinnamate in cosmetic industry, which thought act as an endocrine disruptor interfere with thyroid function. Several sulfonated mesoporous catalysts, without endcapping, were easily synthetized using several alco...

A practical approach has been developed to convert glucals and rhamnals into disaccharides or glycoconjugates with high a-selectivity and yields (77–97%) using a trans-fused cyclic 3,4-O-disiloxane protecting group and TsOH·H2O (1 mol%) as a catalyst. Control of the anomeric selectivity arises from conformational locking of the intermediate oxacarbenium cation. Glucals outperform rhamnals becau...

We report the discovery of the hydrotropic properties of a recyclable aromatic acid, p-toluenesulfonic acid (p-TsOH), for potentially low-cost and efficient fractionation of wood through rapid and near-complete dissolution of lignin. Approximately 90% of poplar wood (NE222) lignin can be dissolved at 80°C in 20 min. Equivalent delignification using known hydrotropes, such as aromatic salts, can...

The synthesis of a biobased aliphatic polyester, poly (hexamethylene sebacate) (PE 6-10) via esterification and alcoholysis reaction steps by reactive extrusion is reported. overall time was decreased down to around 14 min instead roughly 360 in classical batch reactor. A number average molar mass 21,100 g.mol?1 has been reached. operating conditions were first optimized through reactors synthe...

2-Amino-2,3-dideoxy-D-manno-heptonic acid (7) has been synthesized from 2,5,6,7-tetra-O-acetyl-3-deoxy-D-gluco-heptono-1,4-lactone (1), which was readily prepared from D-glycero-D-gulo-heptono-1,4-lactone. O-Deacetylation of 1 followed by treatment with 13:1 (v/v) 2,2-dimethoxypropane/acetone in the presence of p-toluenesulfonic acid gave methyl 3-deoxy-4,5:6,7-di-O-isopropylidene-D-gluco-hepto...