Noncovalent protection, solid-phase

Using a Noncovalent Protection Strategy to Enhance Solid-Phase Synthesis... 

Noncovalent Protection in Solid-Phase Peptide Synthesis... 

The use of crown ethers for protection of the amino group of amino acids offers, in principle, several advantages over the more commonly used protecting groups tert-Boc and Fmoc. The noncovalent nature of the interaction between crown ethers and ammonium ions, coupled with the high affinity of crown ethers for inorganic ions (21), provides the basis for a rapid but mild protection and deprotection scheme. The crown ether protection of lV -amino acids in solution (13-15) and solid-phase syntheses (16,17) has been extensively studied. 

The use of crown ethers for noncovalent protection of A -amino acids and for protection of side chains of Lys or Arg residues has found the most successful utility in the fragment condensation approach to solid- and solution-phase peptide synthesis (15-17). 

Solid-Phase Synthesis of NH Phe-Giy-Giy-Pro-Asp-Leu-Tyr-OH Heptapeptide by the Fragment Condensation Approach Using Noncovalent Protection of DIpeptide Glycylglycine (IV, Fig. 2, see Note 8)... 

Solid-Phase Synthesis of Rhodamlne Labeled Peptide Nucleic Acids using Noncovalent Protection... 

Mayfield, L. D. and Corey, D. R. (1999) Enhancing solid phase synthesis by a noncovalent protection strategy-efficient coupling of rhodamine to resin-bound peptide nucleic acids. Bioorg. Med. Chem. Lett. 9,1419-1422. 

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