Electrochemical cobalt-catalyzed C-H functionalizations were achieved in terms of C-H oxygenation under mild conditions at 23 °C. The robust electrochemical C-H functionalization was characterized by ample substrate scope, whereas mechanistic studies provided support for a facile C-H cleavage. The electrochemical cobalt-catalyzed C-H oxygenation proved viable on arenes and alkenes with excellent levels of positional and diastereo-selectivity, avoiding the use of stoichiometric silver(I) oxidants under ambient conditions.

The full control of redox events is of utmost importance to key aspects of molecular synthesis. As a consequence, chemists have recognized the power of electrochemistry for more than a century to govern electron movements for chemical transformations. Despite numerous benefits associated with electrosynthesis, electrical-current-enabled organic transformations have remained for decades largely dormant in academia and industry. However, organic electrosynthesis has recently experienced a considerable renaissance in terms of implementing electrochemical strategies in the synthetic arsenal. To illustrate this unique potential, we have selected four recent representative examples of contemporary organic electrosynthesis that have attracted major attention toward a toolbox for sustainable synthetic chemists.

Electrochemistry enabled C-H/N-H functionalizations at room temperature by external oxidant-free cobalt catalysis. Thus, the sustainable cobalt electrocatalysis manifold proceeds with excellent levels of chemoselectivity and positional selectivity, and with ample scope, thus allowing electrochemical C-H activation under exceedingly mild reaction conditions at room temperature in water.

Asymmetric pallada‐electrocatalyzed C−H olefinations were achieved through the synergistic cooperation with transient directing groups. The electrochemical, atroposelective C−H activations were realized with high position‐, diastereo‐, and enantio‐control under mild reaction conditions to obtain highly enantiomerically‐enriched biaryls and fluorinated N−C axially chiral scaffolds. Our strategy provided expedient access to, among others, novel chiral BINOLs, dicarboxylic acids and helicenes of value to asymmetric catalysis. Mechanistic studies by experiments and computation provided key insights into the catalyst's mode of action.

Electrocatalysis has been identified as a powerful strategy for organometallic catalysis, and yet electrocatalytic C-H activation is restricted to strongly N-coordinating directing groups. The first example of electrocatalytic C-H activation by weak O-coordination is presented, in which a versatile ruthenium(II) carboxylate catalyst enables electrooxidative C-H/O-H functionalization for alkyne annulations in the absence of metal oxidants; thereby exploiting sustainable electricity as the sole oxidant. Mechanistic insights provide strong support for a facile organometallic C-H ruthenation and an effective electrochemical reoxidation of the key ruthenium(0) intermediate.