Highly Stereoselective Peptide Modifications through Pd-Catalyzed Allylic Alkylations of Chelated Peptide Enolates

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Saarland University

Abstract

Deprotonation of peptides in the presence of zinc chloride gives rise to highly reactive nucleophiles that can be subjected to palladium-catalyzed allylic alkylation reactions. Excellent diastereoselectivities are obtained that are nearly independent of the allylic substrate used. By using this protocol, highly functionalized side chains can also be incorporated in excellent yields and selectivities. The stereochemical outcome of the reaction is exclusively controlled by the peptide chain as long as terminal π-allyl–palladium complexes are involved. Probably, there is a threefold coordination, at least, of the deprotonated peptide chain to the chelating zinc ion. In such metal peptide complexes, one face of the generated enolate is shielded by the side chain of the adjacent amino acid, thus directing the electrophilic attack onto the opposite face. This behavior explains why an S amino acid always generates an R amino acid (and the other way round).

Details

Original languageEnglish
Pages (from-to)6204-6211
Number of pages8
JournalCHEMISTRY: A EUROPEAN JOURNAL
Volume13
Issue number21
Publication statusPublished - 7 May 2007
MoE publication typeA1 Journal article-refereed

    Research areas

  • allylic alkylation, asymmetric synthesis, chelates, palladium, peptide modifications, peptides

ID: 11164194