Ligands for Practical Rhodium-Catalyzed Asymmetric Hydroformylation

A series of bis-phosphite and bis-phosphine ligands for asymmetric hydroformylation reactions has been evaluated. Bis-phosphite ligands lead, in general, to high regioselectivities across a range of substrates while good enantioselectivities are limited to only a few examples. We found that bis-phospholane-type ligands, such as bis-diazaphospholanes and bis-phospholanes, can lead to very high regio- and enantioselectivities for several different substrates.