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Updated: May 18, 2026

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Study of chemical ligation via 17-, 18- and 19-membered cyclic transition states
Siva S Panda1, Claudia El-Nachef, Kiran Bajaj
1Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA.
Abstract:
Unprotected S-acylated cysteine isopeptides containing α-, β- or γ-amino acid units have been synthesized, and their conversion to native hexapeptides by S- to the N-terminus ligations involving 17-, 18- and 19-membered cyclic transition states have been demonstrated both experimentally and computationally to be more favorable than intermolecular cross-ligations.
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