Chiral Ferrocenyl N, P Ligands In Catalytic Asymmetric Synthesis Of Research

A new type of chiral copper complexes of N, P-ferrocenyl ligands 36-40 with central and planar chirality as efficient catalyst was applied to the enantioselective addition of diethylzinc to the iV-diphenylphosphinoylimines.Their application in the copper catalyzed enantioselective addition of diethylzinc to the chalcones was also studied. A convenient and practical procedure for the synthesis of methyl N-ferrocenylmethyl aziridine 51 from the N-ferrocenylmethyl amino alcohol 50 in the presence of DTPP was developed.1. The synthesis of N, P-ferrocenyl ligands 36-40 and their application in the enantioselective addition of diethylzinc to the N-diphenylphosphinoylimines.Chiral ferrocenyl ligands 36-40 were easily synthesized according to the literature. They are used in the copper-catalyzed asymmetric addition of of diethylzinc to the N-diphenyl-phosphinoylimines and up to 97% ee was obtained. The lower ee with 40 compared with 36 and 37 suggests the mismatched nature of the (R) planar chirality with the (R) central chirality. Compound 36 and 37 were the matched case in terms of planar and central chirality groups.2. The application of N, P-ferrocenyl ligands 36-40 in the enantioselective conjugate addition of diethylzinc to the chalcones.Chiral ferrocenyl ligands 36-37 and 40 were used in the copper-catalyzed asymmetric congjugate addition of diethylzinc to the chalcones and up to 92% ee was obtained. The lower ee with 40 compared with 36 and 37 suggests the mismatched nature of the (R) planar chirality with the (R) central chirality. Compound 36 and 37 were the matched case in terms of planar and central chiralities groups. In addition, the "ortho-effection" of the substrates was found.3. The synthesis of methyl N-ferrocenylmethyl aziridine 51Chiral ligands 51a-c were prepared easily from available L-aminoacid by the esterification, condensation, reductive alkylation, cyclization. Retrosynthetically, the enantiomerically pure aziridine is a direct precursor for the preparation of chiral ferrocenyl ligands with planar and central chirality. A convenient and practical procedure for the synthesis of methyl JV-ferrocenylmethyl aziridine 51 from the N-ferrocenylmethyl amino alcohol 50 in the presence of DTPP was developed.