Epoxidation of olefins catalyzed by novel Mn(III) and Mo(IV)-Salen complexes immobilized on mesoporous silica gel: Part II: Study of the catalytic epoxidation of olefins

Mn(III) and Mo(IV)-Salen complexes homogeneous and immobilized on a silica surface have been tested in the catalytic epoxidation of cyclooctene and cyclohexene with tert-butylhydroperoxide (TBHP) and hydrogen peroxide (HP) as an oxidant. The effects of reaction conditions on the epoxide yield as well as the epoxidation rate with different catalysts have been established. The catalytic decomposition of TBHP by manganese and molybdenum-Salen complexes has been studied. The peptide immobilized Salen complexes were compared in catalytic activity with ester bound ones. The immobilized catalysts show stable catalytic activity in manifold reuses. The Mo-Salen complexes homogeneous as well as immobilized exhibited high catalytic activity for the epoxidation of cyclooctene, whereas Mn-Salen complex systems cause additionally non-productive decomposition of hydroperoxide.

Graphical abstractHomogeneous Mn(III) and Mo(IV)-Salen complexes and those immobilized on a silica surface were studied in the catalytic epoxidation of cyclooctene and cyclohexene with tert-butylhydroperoxide (TBHP) and hydrogen peroxide (HP) as an oxidant.Figure optionsDownload full-size imageDownload as PowerPoint slide