Regioselective 1,2-hydroboration of N-heteroarenes using a potassium-based catalyst

Herein, we present a regioselective hydroboration of N-heteroarenes with pinacolborane (HBpin) in the presence of commercially available potassium-based catalysts, leading to 1,2-regioselective hydroboration of quinoline products (up to 99%) and 1,4-regioselective hydroboration of pyridine products (up to 95%) in high to excellent yields. Comprehensive experimental details and mechanistic studies coupled with kinetic investigation led to the proposed mechanism for better understanding of why 1,2-regioselective hydroboration of quinolines is achieved using potassium-based catalysts. Furthermore, the reuse experiment of this KH system demonstrated its long-life catalytic performance by maintaining up to 99% yield of the 1,2-regioselective hydroboration product over 7 sequential additions of starting materials.