N-Heterocyclic carbene/photo-cocatalyzed oxidative Smiles rearrangement: synthesis of aryl salicylates from O-aryl salicylaldehydes

Abstract

The N-heterocyclic carbene/photo-cocatalyzed oxidative Smiles rearrangement of O-aryl salicylaldehydes was developed. Both electron-deficient and electron-rich aryls worked well as migrating groups, giving the corresponding aryl salicylates in good yields. This reaction features formation of two new C–O bonds and one C–O bond cleavage via metal-free oxidation of the Breslow intermediate using oxygen as the terminal oxidant and following the Smiles rearrangement under photocatalysis.