Dual role of pyridine N-oxides in ruthenium porphyrin-catalyzed asymmetric epoxidation of olefins

摘要

The most important intermediates in the ruthenium porphyrin-catalyzed epoxidation of olefins by pyridine N-oxides are shown to be N-oxide-coordinated Ru-IV=O complexes. With a chiral ruthenium porphyrin catalyst, the enantioselective epoxidation of terminal aromatic olefins proceeds with up to 80% ee. [References: 18]