Fast Oxidative Coupling Giving Functionalized Biaryls via Organocuprates

A fast, continuous‐flow, and sequential reaction system composed of organolithium generation–transmetalation–coupling within seconds are developed. The choice of oxidants and the equivalent of copper species remarkably vary the reaction selectivity toward the biaryl coupling and/or the phenol formation. Short‐lived aryllithium species, including bromo‐, cyano‐, or nitro‐substituents, are successfully controlled under fast‐flow conditions, despite the instability after transmetalation giving the organocopper species.