Сu-catalyzed Pinner reaction of acetonitrile with alcohols

The Pinner reaction refers to the acid catalysed reaction of a nitrile with a variety of nucleophiles under anhydrous acidic conditions, affording a useful key intermediate salt for agrochemical and medicinal research. Acid catalyzed reaction of carbonitriles with alcohols gives an imino ester salts, another versatile heterocyclic building block found in various chemicals and pharmaceutics. However severe reaction conditions prevent the wide application of this reaction. We found that the reaction of primary alcohols with acetonitrile under the action of a CuBr2 catalyst gives esters in 83-95 % yield. The reaction we discovered paves the way for the use of copper catalysis in the Pinner reaction.