Solid-state aromatic nucleophilic fluorination: a rapid, practical, and environmentally friendly route to N-heteroaryl fluorides†

Abstract

A simple mechanochemical protocol for solid-state aromatic nucleophilic fluorination using potassium fluoride (KF) and quaternary ammonium salts was developed. This solid-state fluorination is fast and a variety of N-heteroaryl halides can be efficiently fluorinated within 1 h. Notably, highly polar and high-boiling solvents, which are often toxic and difficult to remove during purification, are not required for this protocol. Moreover, all the synthetic operations can be carried out under ambient conditions without complicated setups involving inert gases. The practical advantages of this mechanochemical protocol suggest potentially widespread applications for the preparation of valuable fluorine-containing molecules in a more efficient, cost-effective, and environmentally friendly manner than existing solution-based protocols.