A Mechanistically and Operationally Simple Route to Metal‐N‐Heterocyclic Carbene (NHC) Complexes
Steven Patrick Nolan, Nikolaos Tzouras, Fady Nahra, Laura Falivene, Luigi Cavallo, Marina Saab, Kristof Van Hecke, Alba Collado, Christopher Collett, Andrew Smith, Catherine Cazin
Chemistry a European Journal, (2020)
N-Heterocyclic carbene, Synthesis, Weak Base, Mechanism, Complexes
Abstract: We have been puzzled by the involvement of weak organic and inorganic bases in the synthesis of metal‐N‐heterocyclic carbene (NHC) complexes. Such bases are insufficiently strong to permit the presumed required deprotonation of the azolium salt (the carbene precursor) prior to metal binding. Experimental and computational studies provide support for a base‐assisted concerted process that does not require free NHC formation. The synthetic protocol was found applicable to a number of Transition Metal‐ and Main Group‐centered NHC compounds and could become the synthetic route of choice to form M‐NHC bonds.