Homogeneous and encapsulated within the cavities of zeolite Y chiral manganese and copper complexes with C2-multidentate ligands as catalysts for the selective oxidation of sulphides to sulfoxides or sulfones

A series of manganese and copper complexes with tetradentate C-2-symmetry ligands, [Mn(C-2-ligand)Cl(H2O)]PF6 and [Cu(C-2-ligand)]ClO4, have been synthesised and characterised as homogeneous and encapsulated into the supercages of a large pore sized USY zeolite. These Mn and Cu complexes are excellent catalysts for the selective oxidation of organic sulphides to sulfoxides or sulfones with high selectivity, and moderate to low enantioselectivity. The chelation of zeolite-exchanged Mn2+ by C-N-containing ligands gives rise to a whole class of heterogeneous liquid phase oxidation, which exhibits similar catalytic performances than the homogeneous ones. Moreover, those heterogenised catalysts can be recycled in successive runs, by a simple filtration, without a significant loss of activity and selectivity. (C) 2002 Elsevier Science B.V. All rights reserved.