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METAL-LIGAND COOPERATION WITH NHC-PHOSPHONIUM YILDE PINCER COMPLEXES

CHEMISTRY & GREEN CHEMISTRY

 

LCC
Lab: LCC

Duration: NanoX master Internship (8 months part-time in-lab immersion)

Latest starting date: 02/01/2025

Localisation: LCC-CNRS – Toulouse, University Paul Sabatier
205 route de Narbonne – BP 44099
31077 Toulouse cedex 4 – FRANC

Supervisors:
Yves Canac yves.canac@lcc-toulouse.fr
Dmitry Valyaev dmitry.valyaev@lcc-toulouse.fr

This research master's degree project could be followed by a PhD

Work package:
Among the large variety of ligands available, carbon ligands have become essential, especially with the emergence of N-heterocyclic carbenes (NHC). Phosphonium ylides (PY: R3P+−CR2− <-> R3P=CR2), which represent an alternative class of carbon ligands act also as effective Lewis bases in coordination chemistry. Electron-rich NHC-phosphonium ylide Pd(II) complexes were thus recently prepared in the bidentate (A),1 and in the pincer series (B),2 the latter being active in the catalytic allylation of aldehydes. In parallel, a bidentate NHC-based Mn(I) complex (C) featuring a phosphonium ylide (PYr) bound in a reversed fashion to the metal was reported to activate H2 through a new mode of metal-ligand cooperation acting as one of the most efficient catalyst for ketone hydrogenation.3 More recently, an ortho-metalated Pd(II) complex (D) containing such P-coordinated phosphonium ylide was characterized.4 Based on these results, it is envisioned now to prepare unprecedented pincer complexes E exhibiting NHC ligand N-substituted by two phosphonium ylides, one ylide being bound to the metal in a conventional manner by its C- atom to provide strong electron density and the other one in an unconventional manner by its P-atom to bring non-innocent character. The synthesis of complexes E that maintain a vacant coordination site could constitute a step forward in the design of new cooperative carbon-based systems, from a fundamental point of view but also in the perspective of catalytic applications (See corresponding illustration as attached file). We are looking for a motivated candidate for this internship, which will take place in the team “Molecular design of transition metal pre-catalysts” of the LCC-CNRS in Toulouse. The realization of this internship will allow the candidate to acquire expertise in synthetic organometallic chemistry, organic synthesis, homogeneous catalysis and various spectroscopic methods.

References:
References: [1]- I. Benaissa, R. Taakili, N. Lugan, Y. Canac, Dalton Trans. 2017, 46, 12293. [2]- (a) R. Taakili, C. Lepetit, C. Duhayon, D. A. Valyaev, N. Lugan, Y. Canac, Dalton Trans. 2019, 48, 1709. (b) R. Taakili, C. Barthes, A. Goeffon, C. Lepetit, C. Duhayon, D. A. Valyaev, Y. Canac, Inorg. Chem. 2020, 59, 7082. (c) M. El Kadiri, A. Chihab, R. Taakili, C. Duhayon, D. A. Valyaev, Y. Canac, Organometallics 2022, 41, 456. [3]- (a) R. Buhaibeh, O. A. Filippov, A. Bruneau-Voisine, J. Willot, C. Duhayon, D. A. Valyaev, N. Lugan, Y. Canac, J-B. Sortais Angew. Chem. Int. Ed. 2019, 58, 6727. (b) (b) E. S. Gulyaeva, R. Buhaibeh, M. Boundor, K. Azouzi, J. Willot, S. Bastin, C. Duhayon, N. Lugan, O. A. Filippov, J.-B. Sortais, D. A. Valyaev, Y. Canac, Chem. Eur. J. 2024, 30, e202304201. [4]- M. Ameskal, R. Taakili, E. S. Gulyaeva, C. Duhayon, J. Willot, N. Lugan, C. Lepetit, D. A. Valyaev, Y. Canac, Inorg. Chem. 2023, 62, 20129.

Areas of expertise:
Carbenes, ylides, ligand design, cooperativity, pincer complex, metal. Synthetic chemistry, coordination chemistry, homogeneous catalysis, DFT calculations.

Required skills for the internship:
Good knowledge in organic synthesis, organometallic chemistry, and advanced characterization techniques (multinuclear NMR, X-Ray diffraction, MS, IR,...)