Abstract 3-Lithiated 4-tert-butyl-imidazol-2-ylidene, 3-lithiated 4-tert-butyl-thiazol-2-ylidene, and the ZnBr species of the latter, are shown to be stable carbenes by X-ray crystal structure determination. The crystal data are confirmed by 13 C-NMR investigations in solution and quantum-chemical calculations. The exceptional stability of the acyl anion equivalents is due to the p (.) stabilization of the carbene carbon atoms by the adjacent amino (thio) ...
