SYNTHESIS OF OPTICALLY-ACTIVE PHOSPHORANES AND THEIR USE AS LIGANDS IN RHODIUM(I) COMPLEXES

Optically active (phosphirane)Mo(CO)5 complexes have been obtained by starting from chiral styrene oxide. The corresponding tervalent phosphiranes are easily recovered through a stereoselective decomplexation reaction and used as ligands for cationic rhodium complexes. Some preliminary results on the catalytic hydrogenation of olefins show that different diastereoisomers of a phosphirane give a completely different catalytic behavior to their rhodium complexes. Unusually for a monodentate phosphine, significant optical yields are obtained with one of the four diastereoisomers of the P-menthylphosphirane. The actual involvement of phosphirane itself in the catalytic cycle is not fully established.