Dimethyl carbonate: an environmentally friendly solvent for hydrogen peroxide (H2O2)/methyltrioxorhenium (CH3ReO3, MTO) catalytic oxidations

Environmentally friendly oxidations of various organic compounds with the hydrogen peroxide (H2O2)/methyltrioxorhenium(CH3ReO3, MTO) catalytic system have been described in dimethyl carbonate (DMC), a cheap commercially available and benign chemical having interesting solvating properties, low toxicity and high biodegradability. Oxidations proceeded with good conversions and in good yields. Spectrophotometric analysis demonstrated that the [CH3ReO(O–O)2] complex was formed in DMC and that it was stable for several days at room temperature.L'articolo è disponibile sul sito dell'editore: http://www.sciencedirect.co

Catalytic oxidation of catechins to p-benzoquinones with hydrogen peroxide/methyltrioxorhenium

New p-benzoquinones were obtained by oxidation of catechin and epicatechin derivatives with the hydrogen peroxide/methyltrioxorhenium catalytic system. Reactions were carried out both in homogeneous and heterogeneous conditions and proceeded with high conversion and moderate yields. Polymer-supported methyltrioxorhenium systems were used as heterogeneous catalysts. After the first oxidation, the catalytic systems can be recovered and reused for five consecutive times without loss of stability and efficiency. (c) 2005 Elsevier Ltd. All rights reserved