Inhaltszusammenfassung

Ferrocene derivatives with one or two achiral and chiral arms based on alpha-amino acids (Gly, L-Ala, L-Val) attached to the cyclopentadienyl rings were prepared by solution-phase peptide synthesis from N-acetyl- and N-Boc-protected 1'-aminoferrocene-1-carboxylic acids (Boc=tert-butoxycarbonyl). The conformational preference in the solid state of selected examples was elucidated by X-ray crystallography. The chiroptical properties of chiral bis- and trisamides were investigated by circ...Ferrocene derivatives with one or two achiral and chiral arms based on alpha-amino acids (Gly, L-Ala, L-Val) attached to the cyclopentadienyl rings were prepared by solution-phase peptide synthesis from N-acetyl- and N-Boc-protected 1'-aminoferrocene-1-carboxylic acids (Boc=tert-butoxycarbonyl). The conformational preference in the solid state of selected examples was elucidated by X-ray crystallography. The chiroptical properties of chiral bis- and trisamides were investigated by circular dichroism (CD) spectroscopy in solution. The conformational preference was studied by NMR and IR spectroscopy, as well as by molecular modeling (IFT). For the bisamides, a conformational library is observed in solution. Increasing the steric bulk of the amino acid side chain disfavors several energetically accessible conformers of bisamides and specific conformers can be selected by changing the environment (type of solvent; solid/solution). For the trisamides, a single conformer is highly stabilized by two intramolecular hydrogen bonds irrespective of the size of the protecting group, the size of the amino acid side chain and the medium. » weiterlesen» einklappen

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DDC Sachgruppe:
Chemie