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...

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...

The specific deamidation of 2-acetamido-1,3,4,6-tetra-O-acetyl-alpha-D-glucopyranose is achieved by p-toluenesulfonic acid-promoted hydrolysis of 2-methyl-(3,4,6-tri-O-acetyl-1,2-dideoxy-alpha-D-glucopyrano)-[2,1 -d]-2- oxazoline 2 to give quantitative formation of the 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-alpha-D-glucopyranose p-toluenesulfonate (5d). This two-step procedure provides an amino...