Selective synthesis of -phenols from bio-benzoic acids via regulating the adsorption state.

Phenols are important building blocks widely applied in many fields. The pronounced orientational effect of the phenolic hydroxyl group makes achieving selective synthesis of -phenols challenging. Accessing -phenols needs lengthy synthetic sequences. Herein, we first developed a heterogeneous CO-mediated CeO-5CuO catalyst for decarboxylative oxidation of benzoic acids with a more than 80% selectivity to -phenols. This technology is based on a traceless directing group relay method. The CeO-CuO catalysts with different Ce/Cu ratios exhibited controllable reaction selectivity between decarboxylation and decarboxylative oxidation. Spectroscopy experiments and computational studies showed the adsorption state of benzoic acid was found to be crucial for subsequent reaction pathways. The moderate adsorption on CO-mediated CeO-5CuO catalyst contributes to the distinct selectivity of phenol. Furthermore, the paddlewheel intermediate facilitates the synthesis of -phenols from benzoic acids. This traceless directing group method would promote the development of useful one-pot -substituted phenols from bio-based benzoic acids.