| Abstract |
Theoretical (DFT) calculations predict that soluble Bi salts exhibit catalytic activity toward oxidation of olefins with H2O2. Reaction occurs via two competitive channels: (i) nonradical epoxidation of the C=C double bond and (ii) radical hydroperwddation of the allylic C atom(s) with involvement of the HO center dot radicals, realized concurrently and leading to epoxide/diol and alkenylhydroperoxide products, respectively. The most plausible mechanism of epoxidation includes the substitution of a water ligand in the initial Bi aqua complex, hydrolysis of the coordinated H2O2, one-step oxygen transfer through a direct olefin attack at the unprotonated O atom of the OOH- ligand in [Bi(H2O)(5)(OOH)](2+), and liberation of the epoxide from the coordination sphere of Bi. The main conclusions of the theoretical calculations were confirmed by preliminary experiments on oxidation of cyclohexene, cyclooctene, and 1-octene with the systems Bi(NO3)(3)/H2O2/CH3CN + H2O and BiCl3/H2O2/CH3CN + H2O. |
