Selective synthesis with metalloporphyrin catalysts

Abstract

By using the manganese complexes of the antipodes of the conceptually new chiral strapped porphyrin as catalysts coupled with imidazole, asymmetric epoxidation of prochiral olefins by iodosobenzene was achieved. When the external ligand was absent, the epoxides with the opposite configuration were formed in lower % e.e. In the presence of the external ligand, the enantioselectivity of the reaction depended on the structure of the strap in the catalyst, while no such dependence was observed in the absence of imidazole. The iron complex of chiral p-xylylene-strapped porphyrin effectively catalysed the asymmetric oxidation of sulfides by iodosobenzene in the presence of imidazole.