Strong and Tunable Zinc(II) Cationic Lewis acids: synthesis and use in selective Catalysis – Tu-Zin-Cat

Standard techniques for organometallic synthesis and the handling and storage of electrophilic organometallics
- Characterization of the compounds (NMR techniques - X-ray techniques)
- catalytic runs

- Access to unprecedented «pseudo-naked« Zn2+ di-cation, demonstrated to be highly electrophilic species.
- Access to robust two-coordinated Zn(II) cations

Development of novel fundamental reactivity and derived catalysis proceeding under mild conditions

(1) Adet, N.; Specklin, D.; Gourlaouen, C.; Damiens, T.; Jacques, B.; Wehmschulte, R. J.; Dagorne, S. Towards Naked Zinc(II) in the Condensed Phase: A Highly Lewis Acidic ZnII Dication Stabilized by Weakly Coordinating Carborate Anions. Angewandte Chemie International Edition 2021, 60 (4), 2084–2088. doi.org/10.1002/anie.202012287.

Zn(II) is frequently referred to as Nature’s Lewis acid. Cationic low-coordinate Zn(II) organometallics exhibit an enhanced Lewis acidity, of interest for polar/unsaturated substrates activation. The strength of Lewis acidity may, in principle, be tuned by the charge of the Zn(II) center as well as the nature/number of external ligating ligand(s). The present project aims at: 1) the development of a broad family of Zn(II)-based (organo-)cations with tunable and controllable Lewis acidity, primarily through the coordination (or absence of coordination) of N-heterocyclic carbene (NHC) ligand(s) ; 2) the study of such panel of Zn(II) cations for tailored, sustainable and selective catalytic transformations using Zn(II) cations with finely tuned Lewis acidity as catalysts. The fundamental novelty and significance include an access to unprecedented organozinc and “pseudo-naked” Zn2+ di-/mono-cations. Their fundamental reactivity will be studied and such tunable and strong Lewis acids will exploited as catalysts in reactions of current interest, including their use for the selective transformation of biomass substrates (carbohydrates and sorbitol) in added value products and for the hydro-elementation (hydro-boration/-silation) of alkenes/alkynes.