Convergent Paired Electrolysis Enables Electrochemical Halogen-Atom Transfer-Mediated Alkyl Radical Cross-Coupling
Xiang Sun, Ke Zheng
Abstract
The direct cross-coupling of unactivated alkyl halides with aryl or heteroaryl partners remains a fundamental challenge in synthetic chemistry due to their inertness and propensity for side reactions. Herein, we report a transition-metal-free electrochemical halogen-atom transfer strategy that enables efficient alkyl radical cross-coupling via convergent paired electrolysis. In this system, anodically generated α-aminoalkyl radicals mediate the activation of alkyl iodides, while aryl/heteroaryl aldehydes or nitriles undergo cathodic reduction to afford persistent ketyl radical anions or aryl radical anions. The matched redox processes facilitate selective radical–radical anion cross-coupling to furnish diverse alcohols and C(sp 3 )–C(sp 2 ) coupling products under mild conditions. This operationally simple, scalable protocol exhibits broad functional group tolerance and is applicable to a wide range of primary, secondary, and tertiary alkyl iodides and structurally diverse aryl and heteroaryl coupling partners. The utility of this strategy is further demonstrated in the late-stage modification of natural products, biomolecules, and pharmaceuticals.