Asymmetric Synthesis Catalyzed by Chiral Ferrocenylphosphine-Transition Metal Complexes. I. Preparation of Chiral Ferrocenylphosphines

Article abstract of DOI:10.1246/bcsj.53.1138

As chiral ligands for transition metal complex catalyzed asymmetric reactions, various kinds of chiral ferrocenylphosphines, which have planar chirality due to 1,2-unsymmetrically substituted ferrocene structure and also have a functional group on the side chain of the ferrocene nucleus, were prepared. (S)-N,N-dimethyl-1-<(R)-2-(diphenylphosphino)ferrocenyl>ethylamine <(S)-(R)-PPFA>, (S)-N,N-dimethyl-1-<(R)-1',2-bis(diphenylphosphino)ferrocenyl>ethylamine <(S)-(R)-BPPFA>, and their dimethylphosphino derivatives were prepared by way of lithiation of optically resolved N,N-dimethyl-1-ferrocenylethylamine.The 1-(dimethylamino)ethyl group on the ferrocenylphosphines was converted stereospecifically by nucleophilic substitution reactions into 1-methoxy-, 1-hydroxy-, 1-diphenylphosphino-, and several 1-(dialkylamino)ethyl groups. 1-Diphenylphosphino-2-(dimethylaminomethyl)ferrocene (FcPN) was optically resolved via its phosphine sulfide dibenzoyltartaric acid salt.The relationship between CD spectra of the chiral ferrocenylphosphines and the configuration of their planar chirality is discussed.