Novel Chiral 1-(ferrocenylalkyl)-(S)-prolinols and their Application in Enantioselective Synthesis

Diastereomeric ferrocenylphosphine ligands, (−)-(S,R,pS)-BPPF-Pro (3a) and (+)-(S,S,pR)-BPPF-Pro (3b), containing the (S)-prolinol moiety were prepared. A detailed structural elucidation of these ligands was carried out using NMR. The Pd-complexes of these ligands were used for enantioselective catalysis of allylic substitution reactions of rac-(E)-1,3-diphenyl-3-acetoxyprop-1-ene with C-nucleophiles generated from pentan-2,4-dione and dimethyl malonate. A series of chiral ferrocene aminoalcohols with (S)-prolinol moiety (4a–c) were also prepared. The role of the configuration of stereogenic centers for stereoselectivity in diethylzinc addition to benzaldehyde was studied.