Catalytic hydroxylation of arylthianthrenium salts with nitrous oxide

We present a catalytic protocol for the conversion of aryl thianthrenium salts to the corresponding phenols, by means of a nickel catalyst and N2O. The method tolerates various functional groups and permits the hydroxylaiton of functionalized molecules. Capitalizing on the high selectivity in the introduction of the thianthrene unit in aryl groups, the method represents a formal hydroxylation of aromatic C–H bonds.