Tridentate NNN Ligand Associating Amidoquinoline and Iminophosphorane: Synthesis and Coordination to Pd and Ni Centers

Abstract

The synthesis of a tridentate NNN ligand incorporating an amidoquinoline and an iminophosphorane (L R H, R =Ph, Cy) was carried out. Coordination to Pd II and Ni II precursors gave as expected square planar complexes of general formula [L R MCl]. The most surprising result came from the reaction of L Ph H with [Ni(COD)2] which gave a Ni II-phenyl complex bearing a tridentate amidoquinoline-aminophosphine ligand. This rearrangement would result from a proton transfer assisted by the Ni 0 when stabilized by a phenyl substituent at the phosphorus, as suggested by DFT calculations and complementary experiments. This nickel-phenyl complex formed the corresponding benzoyl complex under a CO atmosphere. X-ray crystallography: Data were collected at 150 K on a Bruker Kappa APEX II diffractometer using a Mo-κ (λ=0.71069Å) X-ray source and a graphite monochromator. The crystal structures were solved using Shelxt 35 or oleix 36 and refined using Shelxl-97 or Shelxl-2014. 37 ORTEP drawings were made using ORTEP III 38 for Windows or Mercury. Details of crystal data and structure refinements are summarized in Table S1 and S2. ASSOCIATED CONTENT Supporting Information Detailed X-ray data, NMR spectra, complete Gaussian reference, computed Cartesian coordinates, energies, and frequencies.

Arene displacement, C–H activation and acetonitrile insertion reactions enabled by coordination of a functionalized iminophosphorane to a RuII–p-cymene scaffold

“…[6][7][8][9] Monofunctionalized iminophosphorano-phosphines are even more interesting due to their difunctionality, having both soft-and hard-donor centers, which makes them ideal candidates to interact with both low-valent and high-valent metals. [10][11][12][13][14][15][16][17] The tunability of monofunctionalized iminophosphorano-phosphine ligands permits precise adjustments to both steric and electronic properties through the modification of substituents on the phosphorus and nitrogen atoms and this ability enables the design of ligands tailored to specific catalytic applications. 18 Their ability to engage in various coordination modes, encompassing monodentate, bidentate, and chelating interactions, enhances their efficacy in transition metal chemistry.…”