The application of an aryl hydrazine linker prevents ß‐elimination side products in the SPPS of <i>C</i>‐terminal cysteine peptides

Abstract

Solid-phase synthesis allows for the preparation of some complex cysteine-containing peptides with both a high yield and purity. However, side reactions during chain elongation such as modification of amino acid residues have been found in C-terminal cysteine peptides. We identified 3-(1-piperidinyl)-alanine peptides, corroborated the mechanism of the side reaction, and introduced an efficient approach for the Fmoc-based synthesis of C-terminal cysteine peptides using an aryl hydrazine linker.