A Synthetic Approach to a Peptide α‐Thioester from an Unprotected Peptide through Cleavage and Activation of a Specific Peptide Bond by N‐Acetylguanidine

Abstract

A different route to peptide α-thioesters through a new peptide-bond-cleavage method at a cysteine residue by S-thiocarbonylation and subsequent treatment with N-acetylguanidine is described (see scheme). The resultant peptidyl-N-acetylguanidine can be converted into the corresponding peptide α-thioester and is also usable as an alternative to a peptide α-thioester. This method allows efficient kinetically controlled ligation in the presence of thiols. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. 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.