Alcohol oxidation reactions are widely used for the preparation of aldehydes and ketones. The electrolysis of alcohols to carbonyl compounds have been underutilized owing to low efficiency. Herein, we report an electrochemical oxidation of various alcohols in a continuous-flow reactor without external oxidants, base or mediators. The robust electrochemical oxidation is performed for a variety of alcohols with good functional group tolerance, high efficiency and atom economy, whereas mechanistic studies support the benzylic radical intermediate formation and hydrogen evolution. The electrochemical oxidation proves viable on diols with excellent levels of selectivity for the benzylic position.

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Direct electrochemical oxidation of alcohols with hydrogen evolution in continuous-flow reactor

Facile synthesis of pyrazoles by iron-catalyzed regioselective cyclization of hydrazone and 1,2-diol under ligand-free conditions

Trichloroisocyanuric acid mediated one-pot synthesis of 3,5-diarylisoxazoles from α,β-unsaturated ketones

Bis salicylaldehyde ethylenediamine Schiff base (Salen) and its complexes with three metal ions (Co2+, Ni2+, Zn2+) were prepared, and characterized by infrared spectroscopy(IR). Using air as oxygen source, the optimum reaction conditions for the catalytic oxidation of 0.05 mol benzoin by Co (Salen) were obtained by orthogonal test as follows: base KOH 2 g, catalyst 1.5 g, N, N-dimethylformamide(DMF) as solvent, reaction temperature 40 °C, reaction time 1 h. Under these conditions, the catalytic performances of different metal complexes were investigated. The catalytic activity of Co(Salen) was the best one, the yield of benzil was up to 93.6%, the number of Ni(Salen) and Zn(Salen) was 86.3% and 82.1%, respectively. The reused catalytic performance of M(Salen) complex was also studied. The catalytic activity of Co(Salen), Ni(Salen) and Zn(Salen) was stable after 4 times recycle, the yield of benzil was 71.4%, 63.3% and 57.4%, respectively, and it was easy for catalyst recycling. The oxidation product was certainly benzil with high purity according to the characterization results of melting point(MP), IR, high performance liquid chromatography(HPLC) and 1H nuclear magnetic resonance(1H NMR). Compared with the common synthetic method of benzil, this one has the advantages of friendly environment, low cost and easy operation. It is a simple and green way to synthesize benzoyl efficiently.

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Synthesis of Benzil by Air Oxidation of Benzoin and M(Salen) Catalyst

An Efficient Chemical Conversion of Glycerol to Dihydroxyacetone

A rapid and convenient oxidation of secondary alcohols

4-tert-Butylcyclohexanol is rapidly converted to 4-tert-butylcyclohexanone with swimming pool bleach in a homogeneous reaction at room temperature. This process introduces students to a heterocyclic compound not normally discussed in the introductory course and has significant advantages over standard procedures using swimming pool chlorine or household bleach. Secondary products are removed by filtration and extraction. Product purity can be determined by thin layer chromatography. Solvent evaporation provides a pure product in high yield that can be characterized by melting point, IR spectroscopy, and/or NMR spectroscopy.

Christina Gethers

Papers

A rapid and convenient oxidation of secondary alcohols

Oxidation of 4-tert-Butylcyclohexanol with Swimming Pool Bleach