Abstract
The epoxidation of cyclooctene and cisβstilbene was performed by tetraβnβbutylammonium periodate (__n__Bu~4~NIO~4~)in the presence of (tetraarylporphyrinato)manganese(III) [Mn(por)] and imidazole (im) in various CH~2~Cl~2~/alcohol solvents (alcohol = CH~3~OH, C~2~H~5~OH, nβC~3~H~7~OH, iβC~3~H~7~OH, tβC~4~H~9~OH). In accord with the coordinating abilities of the alcohols to [Mn(por)], the epoxidation yields increased from CH~2~Cl~2~/CH~3~OH to CH~2~Cl~2~/tβC~4~H~9~OH. In the epoxidation of cisβstilbene in the presence of (acetato)(tetraphenylporphyrinato)manganese(III) [Mn(tpp)(OAc)], the cisβ to transβstilbene oxide ratio increased consistently with the bulk of the alcohol in CH~2~Cl~2~/alcohol solvents. Also, it was found that the interaction of [Mn(tpp)(OAc)] and (acetato)(tetramesitylporphyrinato)manganese(III) [Mn(tmp)(OAc)] with __n__Bu~4~NIO~4~ in the presence of imidazole but in the absence of alkenes yields [Mn(tpp)(O)(im)]^+^ and [Mn(tmp)(O)(im)]^+^ complexes. The formation of the Mn=O species for the small linear alcohols was faster than that for the larger ones, whereas the stability of the Mn=O complex was greater in the presence of the bulkier alcohols. Attempts were made to explain these effects.(Β© WileyβVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)