Synthesis and characterisation of hetero-bimetallic organometallic phenylalanine and PNA monomer derivatives

Dalton Trans. 2009 Jun 14:(22):4310-7. doi: 10.1039/b819169g. Epub 2009 Feb 9.

Abstract

The rational, sequential synthesis of two hetero-bimetallic derivatives of the amino acid phenylalanine and one thymine (T) peptide nucleic acid (PNA) monomer is reported. Ferrocene carboxylic acid and (eta-ethene)bis(triphenylphosphine)platinum(0) were successfully reacted with propargylamide amino acid (1a and 1b) or a T PNA monomer derivative (6) to give the expected three bimetallic compounds 4a, 4b and 9 in good yield. An enzymatic route using cross-linked enzyme crystals (CLEC) of subtilopeptidase A in organic solvents gave the ferrocene carboxylate phenylalanine propargylamide precursor (Fc-CO-Phe-NH-CH(2)-CCH, 3a) in comparable yield and purity to the traditional deprotection-peptide coupling sequence. (31)P NMR spectra of these bioorganometallics showed two doublets with (195)Pt satellites corresponding to two chemically different (31)P atoms. Interestingly, in the case of the T PNA monomer derivative 9, these signals were also doubled in a 60 : 40 ratio as a consequence of the existence of two slowly interconverting isomers in solution. Furthermore, the single-crystal X-ray structures of 3a and the hetero-bimetallic phenylalanine derivative 4b were determined, showing the presence of the two organometallics moieties separated by ca. 8.5 A in 4b as well as illustrating the stability of such compounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemical synthesis
  • Alkynes / chemistry
  • Crystallography, X-Ray
  • Ferrous Compounds / chemical synthesis
  • Ferrous Compounds / chemistry*
  • Magnetic Resonance Spectroscopy
  • Metallocenes
  • Models, Molecular
  • Molecular Structure
  • Organometallic Compounds / chemical synthesis*
  • Organometallic Compounds / chemistry
  • Peptide Nucleic Acids / chemical synthesis*
  • Peptide Nucleic Acids / chemistry
  • Phenylalanine / chemical synthesis*
  • Phenylalanine / chemistry
  • Phosphines / chemical synthesis
  • Phosphines / chemistry
  • Platinum / chemistry*
  • Thymine / chemical synthesis*
  • Thymine / chemistry

Substances

  • Alkynes
  • Ferrous Compounds
  • Metallocenes
  • Organometallic Compounds
  • Peptide Nucleic Acids
  • Phosphines
  • Phenylalanine
  • Platinum
  • phosphine
  • Thymine
  • ferrocene