A Zincke-Inspired Cycloreversion/Cyclization Sequence with Arrested Rearomatization: Synthesis of
Jonathan D Dabbs1, Caleb C Taylor1, Benjamin F Livaudais1
1Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.
Organometallics
|September 12, 2025
Summary
This study details a novel Zincke reaction pathway using tungsten-bound pyridinium salts. This method efficiently synthesizes diverse heterocyclic complexes, including multicyclic systems, via a unique ring-opening/ring-closing sequence.
Area of Science:
- Organometallic Chemistry
- Synthetic Organic Chemistry
- Heterocyclic Chemistry
Background:
- The Zincke reaction is a classic method for synthesizing pyridinium salts.
- Transition metal complexes offer unique reactivity pathways not seen in organic chemistry.
Purpose of the Study:
- To investigate the Zincke reaction analogous sequence for pyridinium salts coordinated to a transition metal.
- To explore the synthesis of novel heterocyclic frameworks using this organometallic approach.
Main Methods:
- Reaction of N-sulfonylated pyridinium ligands coordinated to a tungsten complex with primary amines.
- Characterization of intermediates and final products using spectroscopic methods and single-crystal X-ray diffraction (SC-XRD).
Main Results:
- Selective reaction of the N-sulfonylated pyridinium ligand with primary amines.
- Tungsten-stabilized ring-scission and subsequent ring-closure reactions.
- Formation of 30 novel heterocyclic complexes, including 7 multicyclic systems, with 3 confirmed by SC-XRD.
Conclusions:
- The developed method provides a versatile route to complex heterocyclic structures.
- The tungsten fragment plays a crucial role in stabilizing intermediates and directing the reaction pathway.
- This organometallic Zincke reaction analog expands the toolkit for heterocyclic synthesis.
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