Frustrated Lewis Pair‐Catalyzed Hydroboration of Nitriles: FLP Versus Borenium Catalysis

A frustrated Lewis pair‐catalyzed hydroboration of aromatic and aliphatic nitriles was developed. The catalyst provides the primary amines in high yields of 77–99% with catalyst loading as low as 2 mol%. The reaction displays high functional group tolerance towards esters, amides, nitro groups and aliphatic halides. The addition of the diborylated amines to ethyl 3‐phenylpropiolate proceeds with Z‐selectivity with d.r. of >99:1 in 77–90% yield over two steps. The reaction mechanism was investigated by control and computational experiments.