Revolutionary phosgene‐free synthesis of α‐amino acid N‐carboxyanhydrides using diphenyl carbonate based on activation of α‐amino acids by converting into imidazolium salts

Abstract

α-Amino acids imidazolium salt smoothly reacted with diphenylcarbonate to afford the corresponding urethanes. The urethanes were activated by adding carboxylic acid to undergo selective cyclization, leading to successful development of a new phosgene-free process for synthesizing α-amino acid N-carboxyanhydrides (NCAs). Additional Supporting Information may be found in the online version of this article. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.