Tropylium tetrafluoroborate promoted hydroboration of nitriles, imines and amides

The conversions of nitriles, readily available synthetic precursors, into amines, imines or amides are important chemical transformations in both synthetic laboratories and industrial chemistry. There have been a diverse range of methods to promote this type of chemistry; however, a number of limitations still exist. In pursuit of a practical and environmentally benign nitrile hydroboration reaction, we developed a new organocatalytic approach to reduce nitriles, imines or amides with pinacolborane to amines. Valuable derivatives from these amines could be conveniently accessed by introducing further functionalization reactions to crude hydroboration mixtures in one pot.