Year: 2026
Type: preprint
Abstract: Metal-free potent Lewis acids are of great interest in the pharmaceutical and food industries to avoid metal contaminants. Phosphorus pentafluoride (PF 5 ) is a potent Lewis acid, but its practical use is severely restricted by its gaseous state and corrosiveness. Here we report a simple and convenient method for either the rapid or slow in situ generation of PF 5 from widely available and easy to handle hexafluorophosphate (PF 6 − ) salts and either aluminum chloride (AlCl 3 ) or boron trifluoride etherate (BF 3 ·Et 2 O), respectively. The potency of PF 5 in Lewis acid catalysis is demonstrated in the tandem Friedel–Craft alkylation of thiophene derivatives with ketones, where PF 5 outperforms conventional Lewis acids such as BF 3 ·Et 2 O, AlCl 3 , and SnCl 4 .
Source: ChemRxiv
Institution: Université Libre de Bruxelles
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Awards: G2847978413, G6190866197
OpenAlex ID: W7220832094