PREPARATION AND APPLICATION OF A NOVEL TYPE OF CHIRAL BISPHOSPHINE LIGAND (NORPHOS-7X) CONTAINING A HETERO-FUNCTIONAL GROUP

A new chiral bisphosphine ligand containing a carboxyl group has been prepared by use of a silver-ion catalyzed rearrangement as a key step. And it has been applied to the rhodium-catalyzed asymmetric hydrogena tion of the C=N double bond of N-benzoylhydrazone 12, for which on usi ng (2R,3R,7S) -NORPHOS-7-COOH 1 containing a carboxyl group on the lig and, the opposite absolute configuration product 13 was observed as co mpared to using (2R,3R)-NORPHOS that has the same absolute configurati on at the diphenylphosphino bearing carbons. This result showed the po ssibility of the interaction of the carboxyl, group on the ligand with the substrate 12.