Asymmetric Iridium(I)-Catalyzed Allylic Alkylation of Monosubstituted Allylic Substrates with Phosphinooxazolines as Ligands. Isolation, Characterization, and Reactivity of Chiral (Allyl)iridium(III) Complexes

Ir I -catalyzed allylic alkylations of linear aryl-substituted allylic acetates proceed with enantiomeric excess of up to 95% ee using bidentate phosphinooxazolines as chiral ligands. The chiral (π-allyl)Ir III complexes 14 and 15 have been characterized by X-ray crystal structure analysis and spectroscopic data. The stoichiometric reaction between sodium dimethyl malonate and complex 14 proceeded with nucleophilic addition at the central allylic carbon as well as ligand exchange at Ir to give the iridacyclobutane complex 16, which was fully characterized. Complex 16 was transformed into (π-allyl)Ir III complexes by treatment with Lewis acid or iodine.