Photoinduced Zirconium-Catalyzed Cyclopropanation through Activation of gem -Dichloroalkanes

Cyclopropane rings are pivotal structural motifs in medicinal chemistry, yet their synthesis remains constrained by the reliance on unstable carbene precursors with limited structural diversity. Herein, we report a photocatalytic metalloradical strategy for cyclopropanation of aryl alkenes using bench-stable gem-dichloroalkanes as practical carbene equivalents, facilitated by earth-abundant zirconium catalysis. This method accommodates a broad range of vinylarenes with notable functional group tolerance under mild visible-light-driven conditions. Mechanistic investigations reveal that an open-shell Zr(III) metalloradical intermediate plays a crucial role in activating inert C(sp3)–Cl bonds, offering insights into zirconium-mediated radical processes. The utility of this method is exemplified in the streamlined preparation of medicinal scaffolds, with carbonyls serving as practical substitutes for nonstabilized carbenes.