Frustrated Lewis Pair Chemistry Enables N2 Borylation by Formal 1,3‐Addition of a B−H Bond in the Coordination Sphere of Tungsten

Anaïs Coffinet (1, 2) , David Specklin (1, 2) , Laure Vendier (1, 2) , Michel Etienne (1, 2) , Antoine Simonneau (1, 2)

1 LCC - Laboratoire de chimie de coordination
2 UT3 - Université Toulouse III - Paul Sabatier

Dedicated to Professor Max Malacria on the occasion of his 70 th birthday. Abstract: The first example of a formal 1,3-B-H bond addition across the M-N≡N unit of an end-on dinitrogen complex 5 has been achieved. The use of Piers' borane HB(C6F5)2 1 was essential to observe this reactivity and it plays a triple role in this transformation: i) electrophilic N2-borylation agent, ii) Lewis acid in a frustrated Lewis pair-type B-H bond activation and iii) hydride shuttle to the metal center. This chemistry is supported by NMR and solid-state characterization of products and intermediates. The combination of chelate effect and strong sigma donation in the diphosphine depe ligand was mandatory to avoid phosphine dissociation that otherwise led to complexes where borylation of N2 occurred without hydride transfer.

Domaines: Chimie; Chimie de coordination; Chimie inorganique

Anaïs Coffinet, David Specklin, Laure Vendier, Michel Etienne, Antoine Simonneau. Frustrated Lewis Pair Chemistry Enables N2 Borylation by Formal 1,3‐Addition of a B−H Bond in the Coordination Sphere of Tungsten. Chemistry - A European Journal, 2019, 25, pp.14300-14303. ⟨10.1002/chem.201904084⟩. ⟨hal-02324912⟩