Nickel/ligand loading-controlled divergent and selective coupling between redox-active methylenecyclopropanes and ArBr

Abstract

Divergent and selective synthesis has been widely achieved in transition-metal-catalyzed reactions through a ligand property tuning strategy. However, ligand-loading-controlled divergent synthesis has rarely been reported. Due to changes in ligand loading, different metal complexes should be formed and exhibit diverse catalytic properties. Herein, we disclose a Ni/photoredox-catalyzed divergent and selective coupling between redox-active methylenecyclopropanes and aryl bromides through ligand loading adjustment, providing ranges of alkyne derivatives and dibenzylethylene derivatives. Two different catalytic cycles are proposed to demonstrate the generation of two sets of products, where homopropargyl radicals and nickelacyclobutane species should be crucial intermediates in the corresponding catalytic cycle, respectively.