A redox-neutral catechol synthesis

Ubiquitous tyrosinase catalyses the aerobic oxidation of phenols to catechols through the binuclear copper centres. Here, inspired by the Fischer indole synthesis, we report an iridium-catalysed tyrosinase-like approach to catechols, employing an oxyacetamide-directed C–H hydroxylation on phenols. This method achieves one-step, redox-neutral synthesis of catechols with diverse substituent groups under mild conditions. Mechanistic studies confirm that the directing group (DG) oxyacetamide acts as the oxygen source. This strategy has been applied to the synthesis of different important catechols with fluorescent property and bioactivity from the corresponding phenols. Finally, our method also provides a convenient route to 18 O-labelled catechols using 18 O-labelled acetic acid. Catechols are common structural motifs in bioactive molecules and synthetic building blocks. Here the authors report a method to convert phenol derivatives into catechols via an iridium-catalysed redox-neutral C–H hydroxylation, giving diversely substituted products under mild conditions.