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Updated: Jun 20, 2026

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center
Published on: September 28, 2022
Diastereoselective alkylations of a protected cysteinesulfenate
Adrian L Schwan1, Marcus J Verdu, Suneel P Singh
1Department of Chemistry, University of Guelph, Guelph, Ontario, Canada, N1G 2W1. schwan@uoguelph.ca
Abstract:
To further understand stereoselection in the alkylation of sulfenate anions, a protected cysteinesulfenate was generated in THF solution at low temperature. Introduction of a reactive alkylating agent brings about a cysteinyl sulfoxide in 51-75% yield, with diastereomeric ratios at the sulfinyl group ranging from 83:17 to 95:5. An internally complexed lithium counterion is proposed to account for the stereoselectivity.
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