Iridium PC_sp3P-type Complexes with a Hemilabile Anisole Tether

Abstract

A series of iridium PCsp3P complexes based on bis­(2-diisopropylphosphinophenyl)-2-anisoylmethane (PCanisHP) is reported. (PCanisP)­Ir­(H)Cl was generated from the C–H activation of the backbone by [Ir­(COD)­Cl]2 (COD = 1,5-cyclooctadiene), while the dihydride (PCanisP)­Ir­(H)2 was generated by hydride metathesis from (PCanisP)­Ir­(H)­Cl. Both complexes are 18e octahedral complexes and water stable. The hemilability of the anisole tether was probed using CO and PMe3; multiple isomers, in which the anisole substituent was displaced, were generated, showing the flexibility of the ligand backbone. (PCanisP)­Ir­(H)2 showed deuterium incorporation in the hydride, backbone, and anisole positions upon moderate heating in C6D6. Both (PCanisP)­Ir­(H)Cl and (PCanisP)­Ir­(H)2 were precatalysts for transfer dehydrogenation of cyclooctane under moderate conditions.

Bifunctional Pincer Catalysts for Chemoselective Transfer Hydrogenation and Related Reactions

“…The solid‐state molecular structure analysis confirmed metalation of the ligand, displaying an almost perfect octahedral geometry around the iridium center with a cis ‐ and trans ‐positioned chloride ligands: an Cl(1)–Ir(1)–Cl(2) angle of 86.47(5), an P(1)–Ir–P(2) angle of 100.68(5)°, an O(1)–Ir–Cl(2) angle of 92.36(11), and a C(1)–Ir–Cl(2) angle of 171.15(15)°. The Ir–O(1) distance of 2.206(4) Å is a characteristic of coordinating oxygen . The remaining distances are within the usual range for iridium PC( sp 3 )P pincer complexes of this type, which were characterized by us in the past .…”

Metal Complexes Bearing Dianionic Trityl/Aryloxide Ligands: Rational Synthesis, Structural Diversity, and Redox Properties

“…In the crystal structure of the monomeric cyclopentadienyl iridium trityl/aryloxide complex 6b (Figure ), the iridium center is η 3 ‐coordinated with the triarylmethyl group (Ir(1)–C(7) 2.188(3) Å, Ir(1)–C(8) 2.189(3) Å, Ir(1)–C(9) 2.269(4) Å). This is in contrast to the η 1 ‐coordination of the triarylmethyl moiety with Ir in an iridium [PCP] pincer complex . The alkyl/aryloxide ligand also chelates with the iridium center through the oxygen atom (Ir(1)–O(1) 2.081(2) Å), with an acute bite angle (O(1)–Ir(1)–C(7)) of 81.40(11)°.…”

“…This is in contrast to the η 1 -coordination of the triarylmethyl moiety with Ir in an iridium [PCP] pincer complex. [37] The alkyl/aryloxide ligand also chelates with the iridium center through the oxygen atom (Ir 1…”

Synthesis and crystal structure of a disubstituted nickel(II) bis[(dimethylaminophenylimino)ethyl]pyridine chloride complex

“…Non-innocent ligand systems in organometallics can produce secondary reactivity and allow for unique mechanistic and redox properties (Babbini & Iluc, 2015;Praneeth et al, 2012). Redox non-innocence is usually observed with chelate ligands which possess low-lying -systems that can allow for electron transfer (Lyaskovskyy & de Bruin, 2012).…”