Highly efficient and easy synthesis of 2,4,6-triarylpyridines catalyzed by pentafluorophenylammonium triflate (PFPAT) as a new recyclable solid acid catalyst in solvent-free conditions

Pentafluorophenylammonium triflate (PFPAT) was found to be a highly efficient catalyst for the preparation of 2,4,6-triarylpyridines from the reaction of acetophenone derivatives, aromatic aldehydes and ammonium acetate. Present methodology offers several advantages, such as short reaction time, high yields, simple procedure with an easy work-up and the absence of any volatile and hazardous organic solvent. In addition, this catalytic system can act as an active, inexpensive, metal-free, recoverable and recyclable catalyst.