Cobalt/sodium dispersion catalytic system for imine-directed hydroarylation of styrenes

We report a cobalt/sodium dispersion (SD) catalytic system for the imine-directed, branched-selective hydroarylation of styrenes. Sodium dispersion serves as a convenient reductant to generate catalytically active low-valent cobalt species in situ, avoiding the use of Grignard reagents or preformed air-sensitive complexes. A range of aromatic ketimines and styrenes undergo branched-selective hydroarylation in good yields with high regioselectivity characteristic of cobalt catalysis and distinct from Murai-type reactivity under mild conditions. • Sodium dispersion (SD) serves as an effective reductant for in situ generation of low-valent cobalt species. • An operationally simple Co/SD catalytic system enables imine-directed hydroarylation of styrenes. • A broad range of aryl ketimines and styrenes undergo branched-selective hydroarylation.