MANGANESE PORPHYRINS COVALENTLY BOUND TO SILICA AND MONTMORILLONITE K10 AS EFFICIENT CATALYSTS FOR ALKENE AND ALKANE OXIDATION BY HYDROGEN-PEROXIDE

New supported Mn-III-porphyrin-based catalysts were prepared by covale nt binding of meso-tetrakis-(2,6-dichlorophenyl) porphyrin derivatives bearing NH2 or SO3H functions on their meso-aryl rings to either sili ca or montmorillonite K10. All these supported metalloporphyrins effic iently catalysed the epoxidation of alkenes with PhIO. The Mn-III-porp hyrin covalently bound to montmorillonite K10 gave remarkably good res ults for the hydroxylation of linear alkanes such as heptane with PhIO , the obtained yields (54%) being much better than those observed with corresponding homogeneous catalysts. The Mn-III-porphyrin covalently bound to silica was an efficient catalyst for epoxidation of alkenes w ith H2O2 (yields between 65 and 95% under conversion conditions). In t he presence of an excess of substrate, this supported catalyst was fou nd to be able to catalyse alkene epoxidation with yields based on H2O2 between 67% and 88%, as well as alkane hydroxylation with yields betw een 21% (for heptane) and 90% (for cyclooctane).