Divergent Synthesis of Bisphenols and Diaryl Ethers by Metal Compatible Organocatalytic Aerobic Oxidation of Boronic Acids

Abstract Activation of dioxygen by monooxygenase enzymes enables the oxidation of a rich variety of substrates mainly due to the compatibility of this process with redox active metals. The current study shows that similarly to monooxygenases, pyrrole‐proline 2,5‐diketopiperazine (DKP) organocatalyst, in the presence of Hantzsch ester and HFIP is compatible with copper(II) salts for the activation of dioxygen. These findings allow to selectively diverge the oxidation profile of boronic acids for the synthesis of phenols, bisphenols and diaryl ethers by DKP‐promoted aerobic oxidation and subsequent metal oxidative‐coupling or Chan‐Lam‐Evans type reaction of the formed phenols. magnified image