Fused polycyclic imidazoles
This dissertation presents the synthetic efforts toward the generation and stabilization of fused polycyclic poly(imidazole)s based nucleophilic poly(carbene)s. Chapter 1 reviews how fused nucleophilic carbenes have been employed very successfully in a wide variety of catalytic transformations - both as direct (organo-) catalysts and as ligands for catalytic metal centers. Chapter 2 details the study on the fused tricyclic system. In addition to the progress toward the stabilization of tricyclic tris(carbene) there is also presented the synthesis of fused tricyclic monocarbene precursors and the generation and dimerization of the fused tricyclic monocarbene. New methodology for preparation of imidazol(in)-2-ylidene by reduction of chloroimidazolinium salts with sodium-potassium alloy is described. Metal complexes of the targeted monocarbene have been prepared and fully characterized. Chapter 3 is focused on the chemistry of the saturated fused bicyclic system. Precursors for the fused bicyclic bis(carbene) and the fused bicyclic monocarbene have been prepared. The new methodology for preparation of imidazolin-2-ylidene is also applied on the bicyclic monocarbene precursors.