Catalytic Hydrogenation with Rhodium Complexes Containing dipamp‐pyrphos Hybrid Ligands

Very high enantiomeric excesses are more easily achieved when the catalyst contains a C2-symmetric ligand as a chiral inductor—this, however, does not hold for hydrogenation, catalyzed by rhodium complexes with 3,4-bis(phosphino)pyrrolidine ligands (e.g., 1). In the hydrogenation of (Z)-α-acetoamidocinnamic acid the results obtained with the asymmetric ligand are similar to those with the C2-symmetric ligands. Boc = tert-butoxycarbonyl.