Addition of C−H Bonds to the Catalytically Active Complex (PCP)Ir (PCP = η³-2,6-(^tBu₂PCH₂)₂C₆H₃)

Activation of C–O and C–F Bonds by Pincer–Iridium Complexes

“…At room temperature, we observed immediate formation of product resulting from oxidative addition of the aryl C-H bond ortho to the methoxy substituent, which was spectroscopically analogous to (but significantly more thermodynamically stable than) the previously reported (PCP)Ir(Ph)(H) complex [8]. In an effort to effect subsequent C-O bond activation, (PCP)Ir(H)(o-C 6 H 4 OCH 3 ) was heated for 3 h at 90 • C, but this yielded exclusively the cyclometalated product arising from activation of the methoxy C(sp 3 )-H bond (Scheme 4.7).…”

“…Our group has largely focused on pincer-iridium complexes, which have shown a strong tendency toward the activation of C-H bonds. These complexes have been found to effect the oxidative addition of a variety of C-H bonds including those with sp 2 -and sp-hybridized carbon [8][9][10]. Most notable, however, has been the activation of C(sp 3 )-H bonds, leading to alkane dehydrogenation [6,7].…”

Iridium Complexes Containing a PNP Pincer Ligand: Syntheses, Structural Chemistry, and Bond Activations

“…[25] Goldman et al synthesized a phenyl hydride complex that contained a PCP pincer ligand by means of oxidative addition of benzene to [(PCP)-Ir], [26] and similar results were obtained by using a [(PNP)-Ir(coe)]PF 6 (coe = cyclooctene) complex as starting material. [4] Treatment of this complex with chlorobenzene led to selective ortho C-H activation.…”

Transition‐Metal Complexes with Sterically Demanding Ligands: Facile Thermal Intermolecular CH Bond Activation in a Square‐Planar IrI Complex

“…[12][13][14] Detailed studies by various groups clearly established that the CÀH activation process is under kinetic rather than thermodynamic control in most cases. [12,13] Thus, highly reactive species, such as photochemically generated short-lived transients, for example, [Cp*Ir(PMe 3 )] (Cp* = C 5 Me 5 ), are often required, [3,15] while thermally initiated CÀH activation processes under mild conditions are less common. [2,4,16] Herein, we describe a novel square-planar iridium(i) system 1, which undergoes facile thermal intermolecular CÀH activation in benzene at ambient temperature [Eq.…”

“…[30] Related results were recently reported for an iridium cycloalkane-dehydrogenation catalyst bearing a terdentate cyclometalated bisphosphane donor (PCP pincer ligand). [13] Considering the rigid chelating ligand in 1, the cleavage of one of the nitrogen donor arms from the metal center was deemed to be inconsistent with the observed low activation energy. This idea was supported by the DFT calculations, which revealed an IrÀN diimine bond-dissociation enthalpy of 35 kcal mol À1 .…”