Regioselective Synthesis of <i>o</i>-Benzenediboronic Acids via Ir-Catalyzed <i>o</i>-C–H Borylation Directed by a Pyrazolylaniline-Modified Boronyl Group
Ir-catalyzed ortho-directed C–H borylation of pyrazolylaniline (PZA)-modified arylboronic acids with bis(pinacolate)diboron afforded o-benzenediboronic acids in which two boronyl groups are differentially modified by pinacol (PIN) and PZA. By using this borylation after nondirected Ir-catalyzed C–H borylation, o-benzenediboronic acids are conveniently synthesized from unfunctionalized arenes. The differentially