Manganese catalysts and their use for the selective epoxidation of olefins.

Manganese catalysts and their use for the selective epoxidation of olefins. new manganese complexes of formula (I) wherein R {1} selected from H or methyl provided, R_ {2} is methyl or ethyl; and B is a ligand selected from CF {3} SO {3} ^ {-}, CF {3} CO {2} ^ {-}, [(CF {3} CO) {2} CH] + {-}, NO {3} ^ {-}, H {2} PO {2} ^ {-}, HCO {3} ^ {-}, CIO_ {4} ^ {-}, PF_ {6} and SbF_ {6} ^ {-}, and a process for their preparation. The complexes show high catalytic activity in epoxidation reactions of alkenes, can epoxidizing a broad spectrum of substrates using small percentages of catalyst. They have utility in the preparation of intermediates for the production of high added value products such as pharmaceuticals or fine chemicals.