Executive Summary : | The present invention is related the discovery of a new class of C–H borylation catalysts/ligands and their use for the site selective C–H borylation of aromatic, heteroaromatic and aliphatic molecules. The new catalysts have Ir–C(thienyl) or Ir–C(furyl) anionic ligands instead of the traditional diamine-type of neutral chelating ligands used in the standard C–H borylation reactions. It has been demonstrated that the use of these newly discovered catalysts and ligands display excellent reactivity and selectivity for diverse classes of aromatic substrates with high number of isolated yields. Besides, the catalysts and ligands proved to be efficient for a wide range of aliphatic substrates for selective C(sp3)–H bond borylations. Heterocyclic molecules are selectively borylated using the inherent elevated reactivity of the C–H bonds. A number of late-stage C–H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)–H and C(sp3)–H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C–H borylation catalysts that should find wide application in the context of C–H functionalization chemistry. |