Electrochemical Cross-Coupling of Electron-Deficient Olefins.

The coupling of olefins has garnered significant research interest due to its wide-ranging applications in both industrial processes and organic synthesis. However, for olefins with similar electron densities, achieving selective cross-coupling remains a challenge due to competing side reactions, such as homocoupling. The approach taken to alter or regulate the similar redox potentials between two coupling reactants is crucial for achieving high cross-selectivity. To address this, we propose a strategy that leverages the difference in Lewis acid interactions with different substrates to achieve varying degrees of LUMO modification, thereby enhancing the reduction potential difference (ΔEred) between the substrates and improving cross-coupling selectivity. A selective reductive cross-coupling of electron-deficient olefins that possess similar electrochemical properties was achieved with the assistance of catalytic amounts of Lewis acids. This mild protocol offers tunable reduction potentials, amplification of subtle electrochemical differences between substrates, broad substrate scope, and compatibility with the late-stage functionalization of natural products and drug derivatives.