Use of certain manganese-accumulating plants for carrying out organic chemistry reactions

Method for the preparation of a composition practically devoid of organic matter and comprising a metallic or polymetallic agent comprising manganese (Mn) having a degree of oxidation (II) (Mn (II)), a degree of oxidation (III) (Mn (III)) or a degree of oxidation (IV) (Mn (IV)) and optionally a metal or several metals selected from magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca), cadmium (Cd), aluminium (Al), characterized in that it comprises the following steps:

• a) Dehydration of the biomass of a plant or of a plant extract belonging to one of the genera selected from Alyxia, Azolla, Beauprea, Beaupreopsis, Bridelia, Crotalaria, Dicranopteris, Dipteris, Eugenia, Gleichenia, Gossia, Helanthius, Macadamia, Maytenus, Pinus, Phytolacca, Spermacone, Stenocarpus, or Virotia or Grevillea and in particular Grevillea exul ssp. rubiginosa, Grevillea exul ssp. exul and Grevillea gillivrayi that has accumulated manganese (Mn), and optionally a metal or several metals selected from magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca), cadmium (Cd), aluminium (Al),
• b) Grinding the dry biomass of a plant or of a plant extract obtained in step a)
• c) Heat treatment in an oven preferably at a temperature below 500° C. of the ground mixture
• and, if desired, and preferably
• d) Treatment of the ash obtained in step c) with an acid preferably selected from hydrochloric acid, nitric acid, sulphuric acid, acetic acid or trifluoromethanesulphonic acid, nitric acid, perchloric acid, phosphoric acid, trifluoroacetic acid or para-toluenesulphonic acid followed, if desired, by dehydration of the solution or suspension obtained preferably under reduced pressure so as to obtain a dry residue
• and solution or suspension obtained in step d) which, if desired, is subjected
• e) when the product obtained in step d) is a suspension, to a step of removal of the insoluble matter for example by filtration on an inert mineral solid such as Celite or by centrifugation, a step that is followed, if desired, by dehydration of the solution obtained preferably under reduced pressure so as to obtain a dry residue when and/or
• f) an optional complete or partial purification on ion-exchange resins followed, if desired, by dehydration of the solution obtained preferably under reduced pressure so as to obtain a dry residue
• g) and the dry residue obtained in step c), d), e) or f) containing manganese with a degree of oxidation (II) (Mn (II)), which, if desired, in order to convert the manganese with a degree of oxidation (II) (Mn (II)) to manganese with a degree of oxidation (III) (Mn (III)) is subjected either to the action of dioxygen of the air in the presence of OH− ions and then to a treatment with an anhydride such as acetic anhydride
• or to the action of pyrrole optionally substituted in the presence of an aldehyde in order to obtain formation of a porphinato-manganese complex with a degree of oxidation (II), which is subjected to the action of dioxygen of the air
• and the product obtained is subjected to dehydration preferably under reduced pressure in order to obtain a dry residue comprising manganese with a degree of oxidation (III) (Mn (III)) optionally associated with salts such as the chlorides, sulphates or acetates or oxides of at least one metal in particular selected from magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca), cadmium (Cd), aluminium (Al).
• h) and the product in dry form obtained in step c), d), e) or f), which, if desired, is subjected to the action of dioxygen of the air in the presence of OH− ions in order to convert the manganese with a degree of oxidation (II) (Mn (II)) to manganese with a degree of oxidation (IV) (Mn (IV)) and if desired the suspension obtained is subjected to an acid treatment and then to dehydration preferably under reduced pressure so as to obtain a reagent practically devoid of manganese in the form Mn2O4 or Mn2O3 [<3%] comprising manganese with a degree of oxidation (IV) (Mn (IV)) optionally associated with salts such as the chlorides or acetates or oxides of at least one metal in particular selected from magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca), cadmium (Cd), aluminium (Al).
• i) and the product in dry form obtained in step c), d), e) or f), which, if desired, is subjected to electrolysis in an acid medium in order to obtain manganese with a degree of oxidation (IV) (Mn (IV)) in the form of MnO2 practically devoid of other metals.
• j) and the product in dry form obtained in step c), d), e), f), g) or h), which, if desired, is mixed or treated in an acid medium with a support preferably selected from silica, montmorillonite, polygalacturonic acid, chitosan or a mixture of these products in order to obtain a supported catalyst
• k) and the product in dry form obtained in step c), d), e), f), g) or h), which, if desired, is reacted with ligands, preferably organic, optionally under the action of microwaves in order to obtain chelated agents, preferably catalysts, chelated for example with porphyrins.