Multifunctional Organoboron Synthesis through Chelation‐Induced Radical Addition Reactions †

Comprehensive Summary Multifunctional organoboron compounds are powerful synthetic platforms, yet the direct and modular assembly of diverse scaffolds from simple precursors remains a significant challenge. Herein, we demonstrate that the inexpensive inorganic base potassium carbonate (K₂CO₃) serves as a unique chelating agent to unlock previously elusive radical reactivity in α‐iodinated geminal diboron compounds. Mechanistic investigations reveal that carbonate chelation disrupts the conjugation between the boron vacant orbitals and the α‐carbon radical, thereby generating highly reactive α,α‐geminal diboryl radicals. This activation mode was first applied to the conversion of allylic alcohols, providing expedient access to epoxide‐containing geminal diboronates. The scope of this carbonate‐ mediated strategy was further extended to two distinct radical manifolds: an atom‐transfer radical addition (ATRA) with unactivated alkyl‐substituted alkenes, and an atom‐transfer radical elimination (ATRE) with aryl‐substituted alkenes (styrene derivatives). The mild, metal‐free conditions exhibit broad functional group tolerance and have been successfully applied to the late‐stage functionalization of bioactive molecules. This work establishes a robust and scalable platform for the synthesis of functionally dense organoboron building blocks.