Changhe Zhang

Manganese Dioxide Supported on Aluminum Silicate: A New Reagent for Oxidation of Alcohols Under Heterogeneous Conditions

Abstract Manganese dioxide supported on aluminum silicate, under heterogeneous conditions at reflux, selectively oxidized aromatic primary and secondary alcohols into the corresponding aldehydes and ketones, respectively, in yields of 87–96%. The present method failed to oxidize aliphatic alcohols. GRAPHICAL ABSTRACT

New Reagent, Manganese Dioxide Supported on Kieselguhr, for Effective Oxidation of Benzoins

Abstract A new reagent, manganese dioxide supported on kieselguhr, for effective oxidation of benzoins into corresponding benzils under heterogeneous and reflux conditions is described. The present oxidations are completed within 10 h with yields of 86–95%. The main advantages of the present procedure are that the preparation of supported reagent is more convenient and the reaction times are relatively short.

Oxidation of Benzoins to Benzils with Chromium Trioxide Supported on Kieselghur under Viscous Conditions

Selective oxidation of benzoins to corresponding benzils using chromium trioxide supported on kieselghur reagent under viscous conditions at room temperature is described. The present oxidations are completed within 1 hour with the yield between 89 and 98%. The main advantage of present oxidation is that the reaction can be carried out under quite milder reaction conditions as compared to the other reported chromium (VI)-based reagents.

Oxidation of Benzoins with Chromium Trioxide in Dimethyl Sulfoxide

An efficient procedure for oxidation of benzoins to corresponding benzils using chromium trioxide as an oxidant in dimethyl sulfoxide at room temperature is described. The present oxidations are completed within 3 hours with the yields between 87 and 96%. The main advantage of this oxidation is that the reaction is carried out under homogeneous system with very mild conditions.

Efficient Oxidative Cleavage of Oximes to Their Corresponding Carbonyl Compounds with Chromic Acid Supported on Kieselguhr Under Heterogeneous Conditions

An efficient oxidative cleavage of oximes to their corresponding carbonyl compounds with chromic acid supported on kieselguhr reagent under heterogeneous conditions at reflux with a yield between 86 and 96% is described. In these reaction conditions, deoximation of aldoximes required a longer reaction time than that of ketoximes, and the conditions are not suitable for deoximation of aliphatic aldoximes.

An Efficient Oxidation of Benzoins with the Jones Reagent Supported on Kieselguhr

The heterogeneous room-temperature oxidation of benzoins with the Jones reagent supported on kieselguhr provides an efficient method for the preparation of the corresponding benzyls. The oxidations described in the present study were complete within 30 min with yields of between 82–93%.

Oxidation of Benzoins with Ferric (III) Nitrate Supported on Kieselguhr

Efficient and selective oxidation of benzoins to corresponding benzils with ferric(III) nitrate nonahydrate supported on kieselguhr reagent under heterogeneous conditions and reflux is described. The present oxidations are completed within 2 h with the yield between 85 and 95%. The main advantage of this oxidation is that the reaction time is much shorter as compared to the other reported ferric(III) nitrate nonahydrate–based reagents.

Selective Oxidation of Benzoins with Potassium Dichromate Under Viscous Conditions

An efficient procedure for oxidation of benzoins to corresponding benzils using potassium dichromate under viscous conditions at room temperature is described. The procedure can overcome the problems existed in the common solvent-free reactions of the difficulty for the solid molecular collision to react. The present oxidations are completed within 3 hours with the yield between 86–97%.

Oxidation of Benzoins to Benzils with Chromium Trioxide Under Viscous Conditions

Abstract An efficient and selective oxidation of benzoins into corresponding benzils using chromium trioxide under viscous conditions at room temperature is described. The present oxidations are completed within 2 h with the yield of 86–96%. It can overcome the problems of the common solvent-free reactions, in which it is difficult for the solid molecular collision to react.

A Facile Procedure for the Conversion of Oximes to Ketones and Aldehydes with Potassium Dichromate in Dimethylformamide under Homogeneous Conditions

Oxidative cleavage of oximes to their parent corresponding carbonyl compounds using potassium dichromate-dimethylformamide system under homogeneous conditions in good yields is described. The main advantage of the present method is no need of preparation of hexavalent chromium-based reagents due to using a polar aprotic solvent.