Ir-catalyzed borylation of C-H bonds in N-containing heterocycles: Regioselectivity in the synthesis of heteroaryl boronate esters

Abstract

(Chemical Equation Presented) 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; B 2pin2 = bis(pinacolato-O,O′)diboron, dtbpy = 4,4′-tBu2-2,2′-bipyridine). © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.