Asymmetric Olefin Cyclopropanation Catalyzed by Pincer Ruthenium Complexes

We report the development of a class of chiral pincer ruthenium (PCN_Ox)Ru complexes bearing oxazoline-based PCN_Ox ligands for the asymmetric cyclopropanation of olefins with α-diazo carbonyl compounds. These catalysts exhibit high reactivity and stereoselectivity across a broad range of substrates, including monosubstituted, 1,1-disubstituted, and challenging trisubstituted olefins. The present catalyst showed superior performance in the asymmetric intermolecular cyclopropanation of trisubstituted olefins compared to the known (Pheox)Ru catalyst.