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Iridium-catalyzed C–H activation and borylation reactions operate under mild conditions that enable easy and atom-economical installation of the versatile boronate ester group in (het)arenes and alkanes. The standard catalytic system for iridium-catalyzed borylation uses [Ir(cod)(OMe)]2 as a precatalyst, a bipyridine type ligand, and B2 pin2 or HBpin as the borylating agent. Initially, a bipyridine-ligated trisboryl–iridium complex is generated that enables the borylation reaction and the regioselectivity is mainly governed by the sterics of substituents present on the ring. As a result, monosubstituted and 1,2-disubstituted arenes give mixtures of isomers. Significant efforts by several research groups have overcome the selectivity issue for directed proximal C–H borylation by introducing a directing group and newly developed ligands. This short review aims to summarize recent elegant discoveries in directed C(sp2)–H and C(sp3)–H borylation by using heterobidentate ligand (P/N–Si, N–B, and N–C) coordinated iridium catalysts. 1 Introduction 2 Iridium-Catalyzed Directed C–H Borylation of C(sp2)–H Bonds 3 Iridium-Catalyzed Directed C–H Borylation of C(sp3)–H Bonds 4 Conclusions [ABSTRACT FROM AUTHOR]

We report a convenient method for the highly site-selective borylation of 8-arylquinoline. The reaction proceeds smoothly in the presence of a catalytic amount of [Ir(OMe)(cod)]2 and 2-phenylpyridine derived ligand using bis(pinacolato)diborane as the borylating agent. The reactions occur with high selectivity with many functional groups, providing a series of borylated 8-aryl quinolines with good to excellent yield and excellent selectivity. The borylated compounds formed in this method can be transformed into various important synthons by using known transformations. [ABSTRACT FROM AUTHOR]