Iridium-Catalyzed C–H Borylations: Regioselective Functionalizations of Calix[4]arene Macrocycles

We report iridium-catalyzed C–H borylations for the regioselective synthesis of distally disubstituted calix[4]­arene macrocycles. The atom- and step-economical method led to a broad family of calix[4]­arenes in good yields and functional group tolerance. The synthetic utility of the C–H borylation protocol was finally illustrated with several late-stage modifications for the synthesis of elaborate calix[4]­arenes frameworks, otherwise challenging to achieve with commonly employed procedures.