Chiral Bis(oxazoline) Ligands as <i>C</i>₂-Symmetric Chiral Auxiliaries for the Synthesis of Enantiomerically Pure Bis-Cyclometalated Rhodium(III) Complexes

Abstract

The synthesis of enantiomerically pure bis-cyclometalated rhodium(III) complexes using chiral bis(oxazoline) ligands as C2-symmetric chiral auxiliaries is described. Bis(oxazolines) are versatile chiral ligands for asymmetric catalysis but have not been applied to the resolution of racemic mixtures of transition-metal complexes. Due to their C2 symmetry, chiral bis(oxazolines) are particularly useful for the synthesis of nonracemic transition-metal complexes with lower symmetry, and this is demonstrated with the synthesis of an enantiomerically pure rhodium(III) complex containing two different cyclometalated ligands.