Palladium-catalyzed denitrogenative self-carbonylation of arylhydrazine using CO and O2 as an ideal oxidant

An efficient Pd/Cu-catalyzed oxidative self-carbonylation of arylhydrazine with CO and molecular oxygen as an oxidant to afford symmetrical biaryl ketones via C-N bond activation has been developed. In this approach, arylhydrazine hydrochlorides are used as a green arylating agent which releases nitrogen and water as a byproduct. This developed protocol significantly restricts the for-mation of aryl iodide and homo-coupled azobenzene products even under favorable conditions. A library of symmetrical biaryl ke-tones with wide functionalities was synthesized in good yields under mild conditions.