A Base-Mediated Rearrangement of the Benzylic 1,5-Hexadipyridynyl Moiety

Abstract

A previously unrecognized base-mediated rearrangement of a benzylic 1,5-hexadipyridynyl moiety is reported. Upon exposure to base, this structural motif rearranges into a constrained vinyl-pyridine substituted cyclobutene. Computational modeling indicates that the rearrangement takes place following a route involving stepwise deprotonation, shifted reprotonation, and 4 pi-electrocyclization. The reaction rate and the stereochemical outcome is consistent with the experimental observations. Furthermore, nonbase mediates rearrangements, through well-known Cope-like [3,3]-sigmatropic shifts, are found to be high in energy, and therefore, take a backseat to the base-mediated pathway. This rearrangement may provide a novel reactivity pathway of conjugated systems for synthetic methodology development.

Keywords

density functional theory; mechanism; reactivity; rearrangement

Published in

Chempluschem
2025
Publisher: WILEY-V C H VERLAG GMBH

SLU Authors

• Kessler, Vadim

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Other Chemistry Topics

Publication identifier

• DOI: https://doi.org/10.1002/cplu.202500252

Permanent link to this page (URI)

https://res.slu.se/id/publ/143277