Epoxidation of unfunctionalized olefins by Mn(salen) catalyst using organic peracids as oxygen source: a theoretical study.

ABSTRACT: The mechanism and origin of asymmetric induction in the Mn(III)(salen)-catalyzed epoxidation by peracetic acid have been elucidated by the density functional [Becke three-parameter hybrid functional combined with Lee-Yang-Parr correlation functional (B3LYP)] method in two different regimes: with and without an axial ligand. The acylperoxo complexes of Mn(II,III,IV) in cisON cisNO and trans geometrical configurations cannot compete with the catalyst-free Prilezhaev epoxidation. Instead, oxo species perform epoxidation following the O-O bond cleavage in the acylperoxo complexes. The epoxidation may proceed in a concerted and/or radical-mediated stepwise manner. The actual mechanism of the epoxidation depends on the electronic and oxidation state of the oxo species and the nature of the axial

SUBMITTER: Khavrutskii IV 

PROVIDER: S-EPMC395978 | biostudies-literature | 2004 Apr

REPOSITORIES: biostudies-literature