# Synthesis of 2‑Fluoroalkylated Pyridines and Fluoropyridines by Thermal Denitrogenation of N‑Fluoroalkyl-1,2,3-triazoles and Cyclization of Ketenimines

## TL;DR

A new method was developed to synthesize 2-fluoroalkylated pyridines and fluoropyridines using thermal reactions and cyclization.

## Contribution

The paper introduces a novel synthetic pathway for fluorinated pyridines via thermal denitrogenation and cyclization of triazoles.

## Key findings

- 2-Fluoro-6-fluoroalkylpyridines were synthesized via thermal denitrogenation and cyclization of N-fluoroalkyl-1,2,3-triazoles.
- 2-Fluoroalkylpyridines were prepared using a different triazole starting material and a hydride shift step.
- Nucleophilic substitution of the synthesized pyridines produced highly functionalized derivatives.

## Abstract

2-Fluoro-6-fluoroalkylpyridines and their ring-fused
analogues
were synthesized from N-fluoroalkyl-4-alkenyl-1,2,3-triazoles
by thermal denitrogenation, fluorine shift, cyclization, and hydrogen
fluoride elimination. This reaction proceeds via ketenimine intermediates.
Conversely, 2-fluoroalkylpyridines were prepared starting from N-fluoroalkyl-4-alkyl-1,2,3-triazoles and proceeded by denitrogenation,
fluorine shift, hydride shift, cyclization, and hydrogen fluoride
elimination. Nucleophilic aromatic substitution of 2-fluoro-6-fluoroalkylpyridines
afforded highly functionalized 2-fluoroalkylpyridines.