Unexpected rearrangements in the synthesis of an unsymmetrical tridentate dianionic N-heterocyclic carbene

E. Despagnet-Ayoub (1) , Karinne Miqueu (2) , Jean-Marc Sotiropoulos (2) , L. M. Henling (3) , M.W. Day (3) , J.A. Labinger (3) , J.E. Bercaw (3)

1 LCC - Laboratoire de chimie de coordination
2 IPREM - Institut pluridisciplinaire de recherche sur l'environnement et les matériaux
3 Arnold and Mabel Beckman Laboratories of Chemical Synthesis

Starting from the same ethylenediamine species, three valuable carbene precursors were synthesized under differing conditions: a tridentate dianionic N-heterocyclic carbene bearing an aniline, a phenol and a central dihydroimidazolium salt, its benzimidazolium isomer by intramolecular rearrangement and a dicationic benzimidazolium-benzoxazolium salt by changing the Bronsted acid from HCl to HBF4. A DFT study was performed to understand the rearrangement pathway. The structure of a bis[(NCO)carbene] zirconium complex was determined.

Domaines: Chimie de coordination

E. Despagnet-Ayoub, Karinne Miqueu, Jean-Marc Sotiropoulos, L. M. Henling, M.W. Day, et al.. Unexpected rearrangements in the synthesis of an unsymmetrical tridentate dianionic N-heterocyclic carbene. Chemical Science, 2013, 4 (5), pp.2117-2121. ⟨10.1039/C3SC22171G⟩. ⟨hal-00994346⟩