New optically active ‘constrained-geometry’ cyclopentadienyl-phosphine ligands and their metal complexes

Optically active cyclopentadienyl-phosphine ligands were prepared by stereoselective ring opening of spirocyclopentadienes. Optically active metal complexes were made from these new bidentate ligands. A new stereogenic center at rhodium was generated by oxidative addition reactions with high stereoselectivity. The absolute configuration of the major isomer of one rhodium complex was determined by a X-ray structure analysis.