Collect. Czech. Chem. Commun. 1992, 57, 508-524

"Safety-Catch" Protecting Groups in Peptide Synthesis

Marcel Pátek and Michal Lebl

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


A new benzhydryl-type protective groups for amides based on the concept of converting a stable protecting group into a labile one (safety-catch principle) are described. The p-substituted benzhydrylamine derivatives III(a, b), IV(a, b) are shown to be labile toward various acids but in their oxidized state - V(a, b), VI(a, b) exhibit the resistance to conditions commonly used for removal the Boc group. Independent removal of Boc or Fmoc groups, each in the presence of derivative VIa, is demonstrated by a synthesis of Pro-Leu-Gly-NH2. Some mechanistic aspects of deprotection reaction are discussed.