Design and synthesis of optically active trans-chelating diphosphine ligands. Application for catalytic asymmetric synthesis

New chiral diphosphines 2,2"-bis[1-(disubstituted phosphino)ethyl]-1,1"-biferrocene, having both central and planar elements of chirality, was designed for a trans-chelating chiral diphosphine ligand (TRAP) for transition metals and synthesized form optically active N,N-dimethyl-1-ferrocenyl ethylamine. Some transition-metal complexes with the TRAP ligands were prepared and utilized as a chiral catalyst for asymmetric synthetic reactions.