Stable Singlet Carbenes as Organic Superbases
François Vermersch, S Yazdani, Glen P. Junor, Douglas B. Grotjahn, Rodolphe Jazzar, Guy Bertrand
Abstract
Abstract A simple experimental procedure for scaling carbene Brønsted basicity is described. The results highlight the strong basicity of pyrazol‐4‐ylidenes, a type of mesoionic carbene, also named cyclic‐bentallenes (CBA). They are more basic (p K aH >42.7 in acetonitrile) than the popular proazaphosphatrane Verkade bases, and even the Schwesinger phosphazene superbase P 4 ( t Bu). The basicity of these compounds can readily be tuned, and they are accessible in multigram quantities. These results open new avenues for carbon centered superbases.
Topics & Concepts
MesoionicSuperbaseCarbenePhosphazeneChemistryAcetonitrileFormamidesOrganic chemistryComputational chemistryCatalysisPolymerN-Heterocyclic Carbenes in Organic and Inorganic ChemistryCatalytic Cross-Coupling ReactionsCoordination Chemistry and Organometallics