Chitosan supported phthalocyanine complexes: Bifunctional catalysts with basic and oxidation active sites

The immobilisation of water-soluble metallophthalocyanine complexes on chitosan aerogel microspheres affords new bifunctional catalysts which have been used for the aerobic oxidation of β-isophorone. Chitosan is both the support of the metal complex and the organic base necessary for the reaction. These new materials have been characterized by nitrogen adsorption/desorption, scanning electron microscopy, diffuse reflectance UV–vis and 15N NMR spectroscopies. The influence of the reaction parameters on the efficiency of heterogeneous oxidation of β-isophorone, an important substrate for the preparation of flavour and fragrance fine chemicals has been studied. Combination of basic and oxidation sites in one solid material provided a more efficient heterogeneous clean oxidation of β-isophorone by O2 without any waste.