Diastereoconvergence in NHC/photo dual-catalysis: stereoselective boroacylation of internal electron-poor alkenes

-diastereoisomer, providing diastereoconvergence of mechanistic support for the key role of the rotational flexibility of the intermediate alkyl radical. This protocol enabled efficient synthesis of over 50 examples of β-boryl ketones in good to excellent yields, with complete regioselectivity and diastereoselectivity. The broad applicability of this method is further underscored by its successful adaptation to the late-stage functionalization of drug-derived NHC-boranes. Mechanistic studies, including control experiments, photophysical measurements, kinetic investigations, and density functional theory (DFT) calculations, revealed the organocatalytic radical reaction pathway and provided insights into the origins of diastereoselectivity and kinetic behavior.