Site-differentiated polyboron arenes prepared by direct C=H borylation and their highly selective Suzuki-Miyaura cross-coupling reactions

Di- and polyboron (hetero)arenes, site-differentiated with MIDA boronyl (MIDA=N-methyliminodiacetic acid) and pinacolato boronyl (Bpin), were prepared by an iridium-catalyzed direct C=H borylation of readily available (hetero)aryl MIDA boronates. The excellent synthetic uses of these multisite nucleophiles were demonstrated by the high-yield production of a variety of multifunctionalized poly(hetero)arenes with the highly chemoselective Suzuki-Miyaura coupling (SMC) of the Bpin moiety being an essential step. Assembly line: The title reaction was developed for the synthesis of differentiated di- and polyboron-substituted (hetero)arenes from readily available (hetero)aryl N-methyliminodiacetic acid boronates. Subsequent chemoselective and consecutive Suzuki-Miyaura cross-coupling reactions allowed rapid, efficient, and flexible synthesis of multifunctionalized poly(hetero)arenes from simple building blocks.