Metal carbenes are often proposed as reactive intermediates in the late transition metal-catalysed transformations of alkynes. Owing to their high reactivity, however, isolation and structural characterization of metal carbene intermediates in these transformations has remained unknown. Herein, we report the isolation of two acyclic gold and copper carbene intermediates in either Au(I)- or Cu(I...

Phenolic acids constitute a major group of pollutants which are recalcitrant to common biological treatment. In this study synthetic wastewater containing a mixture of p-coumaric and p-hydroxybenzoic acids was evaluated for photo-Fenton pretreatment. The changes in biodegradability (ratio of biochemical oxygen demand to total organic carbon (TOC)) and mineralization (TOC removal) were monitored...

The accumulation of the denitrification intermediates in wastewater treatment systems is highly undesirable, since both nitrite and nitric oxide (NO) are known to be toxic to bacteria, and nitrous oxide (N2O) is a potent greenhouse gas and an ozone depleting substance. To date, two distinct concepts for the modelling of denitrification have been proposed, which are represented by the Activated ...

The RuvC protein of Escherichia coli catalyzes the resolution of recombination intermediates during genetic recombination and the recombinational repair of damaged DNA. Resolution involves specific recognition of the Holliday structure to form a complex that exhibits twofold symmetry with the DNA in an open configuration. Cleavage occurs when strands of like polarity are nicked at the sequence ...

Developing sustainable and clean energy technology is critial to address the current environmental crisis. As an carrier, hydrogen has been getting attention due its abundance, high density, zero carbon emission. Due difficulty of storage transport, electro-oxidation ammonia shows great potential for renewable since it satisfies both supply protection as a carbon-free fuel with content. However...

The synthesis of hyaluronic acid oligomers (tri- and tetrasaccharide) is described. We have followed a pre-glycosylation oxidation strategy. Glucuronic acid units were directly employed in coupling reactions with suitably protected glucosamine derivatives. In order to simplify the purification of synthetic intermediates, a fluorous-assisted strategy has been also explored. Using this approach, ...

Reactive intermediates rather than stable reactants or products have been found to induce large potential responses on an appropriately formulated polymeric membrane electrode, which provides a novel methodology for ultrasensitive potentiometric biosensing based on the horseradish peroxidase-H(2)O(2) oxidation reaction.

A novel strategy of catalytic green aerobic oxidation by surfactant-mediated oxygen reuptake in water offers a new dimension to the applications of surfactants to look beyond as solubility aids and a conceptual advancement in understanding the role of surfactants in aquatic organic reactions through mass spectrometry guided identification of discrete intermediates.

gem-dihydroperoxides as nearly stable peroxidic derivatives of aldehydes and ketones are known important intermediates in synthesis of anti-malaria drugs. also, because containing high concentration of peroxidic oxygen, recently, some of these compounds have been used as solid, efficient and powerful oxidants in many oxidation organic reactions. generally, these compounds are synthesized via pe...

0-Alkyldihydroxyacetone-P and 0-alkyldihydroxyacetone were identified as intermediates in the biosynthesis of Oalkyl-linked lipids. The substrates for the initial reaction are dihydroxyacetone-P and fatty alcohols, and the cofactor requirements are coenzyme A, ATP, and Mg++. The enzyme complex that carries out this reaction was found in microsomes of preputial gland tumors. The keto-intermediat...