Bio-inspired Mn-catalysts immobilized on silica surface: The influence of the ligand synthesis on catalytic behavior

Two approaches are adopted for synthesis of heterogeneous catalysts, a) Grafting of the entire biomimetic catalyst and b) step-by-step Solid Phase Synthesis of the catalyst on the surface of colloidal silica; both of them result in well-dispersed MnII-complexes covalently attached onto the silica surface. These heterogeneous catalysts were found to be efficient and selective for alkenes' epoxidations with H2O2. Interestingly, the catalyst obtained by grafting process it was found to be kinetically much faster and more recyclable than those formed by solid phase synthesis. These data are discussed interlinking synthetic protocols with catalytic behavior with of the active Mn-complex.