(R,R)-N-phenyl-3,4-bis(diphenylphosphino)pyrrolidine: an N-aryl pyrrolidine ligand for enantioselective transfer hydrogenation

Abstract

The N-aryl pyrrolidine diphosphine (R,R)-N-phenyl-3,4-bis(diphenylphosphino)pyrrolidine was obtained from natural tartaric acid. Contrary to our preliminary expectations, this new chiral ligand proved to be less selective than the corresponding N-benzyl pyrrolidine diphosphine. An attempted explanation of the observed behaviour based on the stereochemistry of the ligand as shown by X-ray crystallography is presented.http://www.sciencedirect.com/science/article/B6TGM-42G6XGY-8/1/25fa9c4e0f48edebc992db1e0b302bf