Expanded Perlite-Polyphosphoric Acid (EP-PPA) as a Low-Cost Heterogeneous Solid Acid Catalyst for Green and Metal-Free Synthesis of Nitriles from Aldehydes

Expanded Perlite-Polyphosphoric Acid (EP-PPA) as a solid acid catalyst reported earlier by our group, has been found to be very effective for direct transformation of aldehydes into nitriles.The aforesaid catalyst exhibited excellent catalytic activity in high yielding preparation of a wide range of nitriles under solvent-free conditions.Furthermore, the method consistently has the advantages of environmental acceptability, short reaction times, excellent functional group compatibility and easy experimental and work-up procedures.Importantly, catalyst reusability up to six runs with little loss of catalytic activity made the present procedure better than the most previously reported protocols.