o-xylylenebis (triphenylphosphonium peroxymonosulfate) (1) was easily prepared from an aqueous solution of oxone and o-xylylenebis- (triphenylphosphonium bromide). this compound (1) is a useful and selective reagent for conversion of oximes, semicarbazones and phenylhydrazones to the corresponding carbonyl compounds. the reaction was carried out under solvent-free conditions and in the presence...

a two-dimensional nanolayered polyoxomolybdate, [4,4´-h2bipy] [mo7o22].h2o (1), where 4,4´-bipy = 4,4´-bipyridine, was prepared and characterized by ft-ir and atomic absorption spectroscopies, transmission electron microscopy (tem), x-ray single crystal and powder diffraction (xrd), and thermogravimetric analysis. the catalytic performance of 1 was assessed in the epoxidation of some olefins em...

ammonium monovanadate (nh4vo3) has been devoted as an efficient, commercially available, eco-friendly and reusable catalyst for the synthesis of bis(indolyl)methanes (bims), oxindole derivatives and also michael adducts of indoles at 50 °c under solvent-free conditions. the reusability of this solid acid catalyst in addition with its selectivity has also been examined.

The asymmetric mixed carboligation of aldehydes with thiamine diphosphate (ThDP)-dependent enzymes is an excellent example where activity as well as changes in chemo- and stereoselectivity can be followed sensitively. To elucidate the influence of organic additives in enzymatic carboligation reactions of mixed 2-hydroxy ketones, we present a comparative study of six ThDP-dependent enzymes in 13...

The spectrophotometric method was used to determine the mechanism of chiral interactions between a known chiral selector, tert-butyl carbamoylated quinine (t-BuCQN), and N-derivative amino acids (DNB-Leu). Results obtained on binding constants, free energy of binding (DeltaG), and difference in free energy of binding (DeltaDeltaG) values seem to suggest that there are three possible types of in...

Abstract Ion-exchange membranes (IEMs) are utilized in numerous established, emergent, and emerging applications for water, energy, the environment. This article reviews five different types of IEM selectivity, namely charge, valence, specific ion, ion/solvent, ion/uncharged solute selectivities. Technological pathways to advance selectivities through sorption migration mechanisms transport cri...

Silver(I) complexes catalyse the intramolecular addition of trichloroacetimidates to alkynes. In the absence of a ligand, the selectivity of the reaction is dependent upon the nature of the counter-anion and solvent. The introduction of non-chelating nitrogeneous ligands suppresses competitive Brønsted acid catalysis, improving the yield and selectivity of the reaction.

New compounds with the ethyl hexahydro-1H-pyrrolo[3,2-c]quinoline-2-carboxylate skeleton were prepared by microwave-assisted intramolecular 1,3-dipolar cycloaddition reactions. The reactions were carried out under solvent-free conditions and compared with the same reaction in the presence of a solvent and a catalyst. Steric effects on the selectivity of the reaction were noted and evaluated.

dodecylbenzenesulfonic acid (dbsa) was used as an efficient, cheap and stable brønsted catalyst for acetylation of alcohols and phenols and formylation of alcohols under solvent-free conditions. various primary, secondary and tertiary alcohols were acetylated with acetic anhydride as an acetylating agent under solvent-free conditions in the presence of catalytic amount of dbsa at room temperatu...