Preparative isolation and properties of diastereomeric copper(II) chelates of schiff bases of dipeptides with (α-(N,N-dimethylamino)alkyl)formylcymantrenes

The effect of the planar and central chirality of 1,2(α-(N,N-dimethylamino)alkyl)formylcymantrene on the chromatographic properties of diastereomeric chelates of Cu2+ with Schiff bases from dipeptides and the aminoalklylformylcymantrenes, 1-(N,N-dimethylaminomethyl)-2-formylcymantrene (I) and 1,2(α-(N,N-dimethylamino)ethyl)formylcymantrene (III), has been studied by liquid chromatography. The method described has been shown to allow the separation of diastereomeric chelates of the cymantrene derivative with differing metallocene chirality. The central chirality in III does not make any noticeable contribution to the chromatographic separation of chelates. Acid hydrolysis of chelates after the chromatographic separation gives enantiomers of I and III. The formation of chelates proceeds stereospecifically. 1,3-Isomers of aminoaldehydes of I and III do not form chelates with Cu2+ ion and dipeptides. The synthesis of chelates using L -Ala- L -Ala in the presence of oxygen is accompanied by epimerization of the N-terminal aminoacid moiety of the dipeptide. p]The resulting diastereomeric chelates and optical isomers of aminoaldehydes of cymantrene I and II isolated from them are characterized by elemental analysis data, ORD, PMR, UV and IR spectra.