Polarity-Reversal Strategy for Functionalization of Electrophilic Strained Molecules via Light-Driven Cobalt Catalysis.

Strain-release-driven methodology is as a powerful tool to access structural motifs, highly desirable by pharmaceutical indus-try. The reactivity of spring-loaded cyclic reagents is dominated by transformations relying on their inherent electrophilic reac-tivity. Herein, we present a polarity-reversal strategy based on light-driven cobalt catalysis, which enables the generation of nucleophilic radicals through strain release. Applicability of this methodology is demonstrated by design of two distinct types of reactions: Giese-type addition and Co/Ni-catalyzed cross-coupling. Moreover, a series of electrochemical, spectroscopic, kinetic experiments, and X-ray structural analysis of the intermediate alkylcobalt(III) complex reveal deeper insight into mech-anism of the reaction.