Ir‐Catalyzed Borylation of CH Bonds in N‐Containing Heterocycles: Regioselectivity in the Synthesis of Heteroaryl Boronate Esters

Blocking the way: Substitution at the 2-position in pyridines and other N-heterocycles blocks N-coordination to an Ir center. This steric hindrance provides a substrate-design criterion that allows the Ir-catalyzed borylation of CH bonds, which can be followed by Suzuki–Miyaura cross-coupling in a one-pot reaction (see scheme; B2pin2=bis(pinacolato-O,O′)diboron, dtbpy=4,4′-tBu2-2,2′-bipyridine).