regioselective N-heteroarene hydroboration. Despite these examples, there are very few reports that provide detailed mechanistic analysis of the reactions either experimentally or computationally. We previously demonstrated that an iron(0) complex containing a diphosphinoborane ligand scaffold (complex A) was a suitable pre-catalyst for the hydroboration of terminal olefins. Given the scarce number of literature reports for iron-catalyzed nitrile and N-heteroarene hydroboration, we herein disclose that Complex A is a suitable precatalyst for the hydroboration of both nitriles and N-heteroarenes and provide a combined experimental and computational mechanistic insight into nitrile hydroboration.