The pyridylketene has previously been isolated via matrix isolation and demonstrated potential in the synthesis of N-heterocycles. Herein, we report the synthesis and isolation of the pyridylketenyl anion through conventional synthetic methods, involving metalation and subsequent carbonylation of the readily available 2-pyridyl ylide. Quantum chemical calculations reveal extensive delocalization of the negative charge across the entire molecular framework, resulting in multiple nucleophilic sites that are best described by a series of resonance structures. IR spectroscopic and X-ray diffraction data corroborate this electronic structure, indicating a markedly compressed C–C–C–O moiety. The pronounced charge delocalization enables diverse reactivities and promotes cyclization pathways involving the pyridine nitrogen. Accordingly, the pyridylketenyl anion serves as a versatile precursor for the construction of heterocycles featuring triazolone, quinolizine, and indolizine motifs, underscoring its broad applicability as a building block in heterocycle synthesis.

Increasing the donor strength of Lewis bases is a viable strategy to stabilize reactive electron-deficient species. Herein, we utilize the strong electron-releasing power of ylide substituents to gain...

Aromaticity is a fundamental concept traditionally used to explain the structure, stability, and reactivity of cyclic organic compounds. Heavier analogs have also been investigated for their aromatic ...

Increasing the donor strength of Lewis bases is a viable strategy to stabilize reactive electron-deficient species. Herein, we utilize the strong electron-releasing power of ylide substituents to gain...