Oxygen‐Accelerated Suzuki–Miyaura Coupling Reaction Without Stoichiometric Base Addition

Abstract The Suzuki–Miyaura coupling (SMC) reaction is an efficient method for constructing C(aryl)–C(aryl) bonds. SMC reactions are typically carried out in the presence of base additives (>100 mol%), thereby leading to increased by‐product formation. In this study, the promotional effect of an O 2 atmosphere on the SMC reaction was demonstrated without the requirement for a stoichiometric amount of base. The cross‐coupling product yield was enhanced upon increasing the O 2 pressure within the range of 0.0–0.5 MPa. X‐ray absorption spectroscopy revealed the presence of different Pd species under Ar and O 2 atmospheres. More specifically, Pd(0) nanoparticles were detected in Ar (0.1 MPa), whereas Pd(II) was detected under O 2 conditions (0.5 MPa). Under an O 2 atmosphere, the Pd species in the solution phase promoted the SMC reaction and were re‐adsorbed on the support surface after the reaction at room temperature to provide a reusable catalyst system.