This work focused on the search for alternative metals to replace palladium- and nickel-catalysts by the development of new cobalt(II)- and chromium(II)-catalyzed cross-coupling methodologies. Furthermore, an effective strategy to obtain highly functionalized structural heterocyclic motifs involves the use of polyhalogenated starting materials that can be subsequently functionalized. For this purpose, the use of CrCl2 in highly regioselective cross-coupling reactions of dichlorinated heteroaromatics was demonstrated. Attention was also paid to the effective purging of chromium salts from the desired product by demonstrating the use of various solid supports for the removal of remaining metal traces. Besides the C-C bond formation, this work focused on the replacement of the cost-intensive palladium salt associated with sensitive phosphine ligands in the Buchwald- Hartwig amination reaction. Therefore, the chromium(II)-chloride catalyzed amination of N- heterocyclic chlorides with a range of magnesium amides was developed.
Besides, particular attention was paid to the synthesis and functionalization of unexplored annelated six-membered N-heterocycles having potential use in medicinal and/or material applications: pyrido[3,2-f][1,7]naphthyrdine
