Reduction of Nitriles to Primary Amines Using InCl3-NaBH4 in Tetrahydrofuran

Current methods for the reduction of nitriles consists of working with pyrophoric compounds or toxic heavy metals, currently in the lab a new method for reducing nitriles to primary amines has been developed using InCl₃-NaBH₄ in Tetrahydrofuran which is relatively low toxic in comparison to the usage of Lewis acid reductions and transition metal salt hydrides. It has been found that reacting InCl₃ and NaBH₄ in THF, a BH₃: THF complex and HInCl₂ has generated in situ. With this new method, a variety of aromatic, aliphatic, and hetero-aromatic nitriles were successfully reduced to their corresponding primary amines obtaining yields of up to 99% under ambient conditions. Products were isolated by acid-base extraction.