104337-66-8Relevant articles and documents
Enantioselective Catalysis, 4. Synthesis of N-Substituted (R,R)-3,4-Bis(diphenylphosphino)pyrrolidines. The Use of their Rhodium Complexes for the Asymmetric Hydrogenation of α-(Acylamino)acrylic Acid Derivatives
Nagel, Ulrich,Kinzel, Elke,Andrade, Juan,Prescher, Guenter
, p. 3326 - 3343 (2007/10/02)
A simple synthesis of (R,R)-3,4-bis(diphenylphosphino)pyrrolidine (6a) and some N-substituted derivatives 6b-m is described. 6l and 6m are optically active tetraphosphanes, composed of two (R,R)-3,4-bis(diphenylphosphino)pyrrolidine units and a dicarboxylic residue.The structure of the parent compound 6a was determined by X-ray diffraction.From the phosphanes 6a-m the cationic 1,5-cyclooctadiene-bisphosphane-rhodium complexes 7a-m were prepared.The complexes 7l and 7m are ligand bridged bis(rhodium) dications.The complexes 7a-m were used for the asymmetric catalytic hydrogenation of the α-(acylamino)acrylic acid derivatives 9a-l.Enantiomeric excesses up to 100percent were achieved.Between 1 and 70 at the optical yields do not depend on the hydrogen pressure.The substrate/catalyst ratio can be as high as 50000/1.
