Application of Heterobidentate Rhodium Complexes in Asymmetric Hydrogenation

Significance

While chiral bidentate ligands have become widespread in asymmetric catalysis, the difficulty in their synthesis remains a drawback. It is possible to apply a chiral monodentate ligand along with a non-chiral ligand to afford enantio­induction, but undesired formation of homodimeric complexes can be problematic. The authors report a highly efficient formation of a heterodimeric ligand rhodium complex I, by utilizing ligands capable of hydrogen bonding. Complex I is formed in excellent yield and is shown to react in asymmetric hydrogenations of substituted alkenes, yielding enantioselectivities superior to previous reports.

Review: B. Breit Angew. Chem. Int. Ed. 2005, 44, 6816-6825.