Samarium Diiodide-Mediated Radical Borylation of Alkyl Bromides with Pinacol Borane

The first example of a samarium diiodide-mediated radical borylation reaction between alkyl bromides and pinacol borane was reported. Commercially available alkyl bromides and boron reagents were used as substrates in this method to construct alkyl boronic esters under base-free and ligand-free conditions. Moreover, this approach exhibits excellent functional group tolerance and a broad substrate scope, including the fact that both primary and secondary alkyl bromides are compatible with the reaction. In addition, various molecules with biological activities can also be tolerated by this method.