Regioselective Radical Borylation of α,β-Unsaturated Esters and Related Compounds by Visible Light Irradiation with an Organic Photocatalyst

Radical hydroboration reactions have only recently been reported and are still rare. Here we describe a photoredox radical hydroboration of alpha,beta-unsaturated esters, amides, ketones, and nitriles with NHC-boranes that uses only an organocatalyst and visible light. The conditions are mild, the substrate scope is broad, and the alpha/beta regioselectivity is high. The reaction requires only the organocatalyst; there is no costly metal, and there are no other additives (base, cocatalyst, initiator).

Automated summary

The study describes a radical hydroboration reaction using an organocatalyst and visible light, which is suitable for various substrates, with high regioselectivity and mild reaction conditions.