N–N Atropisomer Synthesis via Electrolyte- and Base-Free Electrochemical Cobalt-Catalysed C–H Annulation

Merging electrochemistry with asymmetric C−H activation has proven as an advantageous alternative to prepare valuable enantiopure molecules. However, established methods require a stoichiometric use of supporting electrolytes to promote electron transfer in solution and often additionally serve as a base to assist C−H bond cleavage, which are hazardous and would produce additional waste. Herein, we described an exogenous electrolyte- and base-free electrocatalytic atroposelective C–H annulation, providing facile and sustainable access to N–N axially chiral isoquinolinones in excellent enantioselectivities and good yields. This protocol is enabled by a combination of simple Co(OAc)2·4H2O and readily available chiral salicyloxazoline (Salox), proceeds well with 13 classes of alkynes, and tolerates a wealth of functional groups for streamlined transformations.