Hybrid supercapacitors, as emerging energy storage devices, have gained much attention in recent years due to their high density, fast charge/discharge and long cyclabilities. Among the wide range of systems covered by this topic, low cost, environmental friendliness power provide MnO2 with great characteristics be a competitive candidate. The present work reports hybrid aqueous supercapacitor ...

The residue from desulfurization and denitrification of exhaust gas treatment process with pyrolusite ore as absorbent is regarded as a potential source of iron and manganese. In this study, an extraction process is proposed for recovery of iron and manganese with ammonium sulphate roasting followed by sulphuric acid leaching. Firstly, the conversion mechanism was analyzed through mineral phase...

The tetrahydroquinolines obtained through the Povarov multicomponent reaction have been oxidized to the corresponding quinoline, giving access to a single product through a two-step sequence. Several oxidizing agents were studied and manganese dioxide proved to be the reagent of choice, affording higher yields, cleaner reactions and practical protocols.

Electrolytic Manganese Dioxide (EMD) material was analyzed by Rietveld refinement of x-ray diffraction patterns to answer the question, “Is EMD composed of gammaor epsilon-MnO2?” An electron diffraction study of EMD using a 20 nanometer spot size electron beam reported observing only the ε-MnO2 structure and no γ-MnO2 structure. However, a Transmission Electron Microscopy (TEM) study of EMD obs...

Regioselective Diels-Alder reactions of acyl-1,4-benzoquinones 1 with, severally, isoprene, trans-piperylene,1-acetoxy-1,3-butadiene and 1-methoxy-1,3-butadiene gave the corresponding adducts 2 in high yield. Treatment of the adducts 2 with manganese dioxide gave regiospecifically the corresponding 1,4-naphthoquinones 3. In several cases, the adducts of the acetylquinones afforded intermediates...

After comparing our previous and newer results for numerous oxidative aromatic iodination experiments using various brands of active MnO2 as the oxidants,we recommend the use of a Chemical Manganese Dioxide (Aldrich CMD; 90 +% MnO2) as the oxidant of choice, since it is satisfactorily pure and chemically active, and is notably less costly than other options.

A streamlined method for the enantioselective synthesis of 2-amino-4H-chromenes from readily available 2-alkyl-substituted phenols and active methylene compounds bearing a cyano group with up to 97% ee is presented. This reaction is a cascade procedure including manganese dioxide mediated C-H oxidation for the generation of o-quinone methides and bifunctional squaramide-catalyzed Michael additi...

Manganese dioxide is employed as an in situ oxidant for the one-pot conversion of alcohols into imines. In combination with polymer-supported cyanoborohydride (PSCBH), a one-pot oxidation-imine formation-reduction sequence is reported. This procedure enables alcohols to be converted directly into both secondary and tertiary amines.

A rapid flow synthesis of oxazolines and their oxidation to the corresponding oxazoles is reported. The oxazolines are prepared at room temperature in a stereospecific manner, with inversion of stereochemistry, from β-hydroxy amides using Deoxo-Fluor®. The corresponding oxazoles can then be obtained via a packed reactor containing commercial manganese dioxide.