Specific 1,2-Hydride Shift in the Boron Trifluoride Catalyzed Reactions of Aromatic Aldehydes with Diazoacetonitrile: Simple Synthesis of β-Ketonitriles

A series of beta-ketonitriles was synthesized within 30 min under mild conditions through the BF3 center dot OEt2-catalyzed addition reactions of diazoacetonitrile to aromatic aldehydes and subsequent 1,2-hydride shift. This method is advantageous in that it is operationally simple, mild and metal-free conditions are used, the substrate scope is wide, and the products are obtained in moderate to high yields (up to 81%). Additionally, gamma, delta-unsaturated beta-ketonitriles are also accessible by this method by using cinnamaldehydes.