Resin-Bound Crypto-Thioester for Native Chemical Ligation

Resin-bound N–sulfanylethylanilide (SEAlide) peptide was found to function as a crypto-thioester peptide. Exposure of the peptide resin to an aqueous solution under neutral conditions in the presence of thiols affords thioesters without accompanying racemization of C-terminal amino acids. Furthermore, the resin-bound SEAlide peptides react with N-terminal cysteinyl peptides in the absence of phosphate salts to afford ligated products, whereas soluble SEAlide peptides do not. This unexpected difference in reactivity of the SEAlide peptides allows for a one-pot/three-fragment ligation using resin-bound and unbound peptides.

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organic Letters, copyright ©American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.orglett.8b00795.