Better boron placement

Abstract

Organic Chemistry Over the past two decades, iridium-catalyzed borylation has proven to be a versatile method for substituting carbon–hydrogen (C–H) bonds that are otherwise relatively inert. Hoque et al. now report a pyridyl thiophene ligand for this reaction that induces the catalyst to target carbonyl-adjacent aryl C–H bonds or nitrogen-adjacent alkyl C–H bonds specifically. Heteroarenes were borylated next to their nitrogen, oxygen, or sulfur substituent. The iridium–ligand complex (bound datively at the pyridine nitrogen but metallated at a thiophene carbon) was conveniently compatible with open-air conditions. J. Am. Chem. Soc. 143 , 5022 (2021).