Peroxidic complexes of vanadium, niobium and tantalum, used as reactants and as catalysts for olefins epoxidation and hydrocarbons hydroxylation

Claim 1

In a process comprising catalytically hydroxylating an aromatic hydrocarbon with hydrogen peroxide or an organic hydroperoxide, to produce a phenolic compound, the improvement wherein the catalyst is a vanadium or niobium or tantalum peroxidic complex selected from the general formulas I to IV ##STR60## wherein M is vanadium, niobium or tantalum, Z and Z', identical or different, are mono or polyaromatic nitrogenous heterocyclic compounds having a carboxylic group vicinal to the nitrogen atom, substituted or not by at least one Y group selected from the nitro, halogen, carboxylate, carboxyamide and hydroxyl groups, Z" is a dianionic tridentate ligand derived from 2,6-pyridine dicarboxylic acid substituted by one or more Y groups selected from the alkyl, aryl, alkyloxy, aryloxy, nitro, halogen, carboxylate, carboxyamide or hydroxyl groups, L and L' identical or different being each a molecule of water or alcohol or a mono or bidentate ligand of electrodonor character, (or forming together a bidentate ligand), said ligand being selected from the group constituted of (a) an aromatic amine (b) a linear or cyclic tertiary amide (c) a phosphoramide (d) an aliphatic or aromatic amine oxide (e) a phosphine, arsine or stibine oxide, A being or proton or a cation or a cationic group selected from: (a) an alkali metal (b) a quaternary ammonium group (c) a phosphonium or arsonium quaternary group.