Refined synthesis of meso-substituted trans-A2B-corroles bearing electron-withdrawing groups

We have refined a one-pot synthesis of trans-A(2)B-corroles via the condensation of 5-(pentafluorophenyl)dipyrromethane with aldehydes followed by macrocyclization mediated by DDQ. After thorough examination of reaction parameters and thanks to the identification of key factors influencing the formation of bilanes and the efficiency of their conversion to corroles, we were able to improve yields from ca. 6 to ca. 20% for a broad range of aldehydes. We proved that these conditions work well also for dipyrromethanes possessing cyano and nitro groups. meso-Substituted alkyl aryl corrole has been obtained for the first time using this procedure.