Synthetic Utility of Chiral Bis(oxazolinyl)phenyl Transition-Metal Complexes

Transition-metal complexes with a chiral bis(oxazolinyl)phenyl (Phebox) ligand can construct suitable chiral environments around metal centers. Thus far, a number of transition-metal complexes in the range of early to late metals have been prepared via transmetalation, cyclometalation, and oxidative addition. The fundamental properties and catalytic activities of the resulting Phebox complexes have been extensively investigated. In particular, the Phebox-Rh and Phebox-Ru complexes were found to serve as efficient and selective catalysts in asymmetric reactions for carbon-carbon bond formation, reduction of unsaturated bonds, and functionalization reactions. In this Account, we summarize details of the Phebox complexes in terms of preparations, coordination chemistry, and catalytic applications.