Arylazopyrazole linked Schiff bases as organocatalysts for the ipso-hydroxylation of arylboronic acids for the synthesis of phenols.

[Display omitted] • A simple metal-free strategy for the synthesis of phenols. • An azopyrazole-linked Schiff base as organocatalyst. • Use of the green solvent system for the synthesis. A simple metal-free strategy for the synthesis of phenols from aryl and hetero aryl-boronic acids using arylazopyrazole linked o -hydroxyl Schiff base has been illustrated. These sustainable ipso -hydroxylations have very short reaction times, using aqueous H 2 O 2 as the oxidant in aqueous-alcoholic medium. The current protocol has been demonstrated to be effective with a variety of electron-rich and electron-deficient aromatic substrates and provides access to a wide range of phenols. This is the first time that an azoyrazole linked Schiff base has been used to increase the nucleophilicity of H 2 O 2 , in oxidative hydroxylation reactions. [ABSTRACT FROM AUTHOR]