Disclosed are substantially enantiomerically pure bis-phosphine compounds comprising a substantially enantiomerically pure chiral backbone linking two phosphine residues wherein one of the phosphine residues has three phosphorus-carbon bonds and the other phosphine residue has two phosphorus-carbon bonds and one phosphorus-nitrogen bond wherein the nitrogen is part of the chiral backbone. The compounds, which have exhibited surprising air stability, are useful as ligands for metal catalysts for asymmetric reactions and have demonstrated excellent results, in particular as rhodium complexes for asymmetric hydrogenation of enamide, itaconate, and .alpha.-ketoester compounds. Also disclosed are novel processes for the preparation of the bis-phosphine compounds and novel intermediate compounds useful in the preparation of the bis-phosphine compounds.