Synthesis and Functionalization of Imidazo[1,2‐ b ]Pyridazine by Means of Metal‐Catalyzed Cross‐Coupling Reactions

This review surveys the recent developments in organometallic‐chemistry‐based methods for the preparation of imidazo[1,2‐ b ]pyridazines by cyclization as well as their functionalization by means of cross‐coupling reactions such as Sonogashira, Heck, Negishi, Suzuki‐Miyaura, Kumada and Stille. In addition, the advances made on the C−H activation of imidazo[1,2‐ b ]pyridazines using C‐arylation, C‐benzylation and C‐alkylation are also reviewed. Furthermore, the recent reports on the N ‐arylation of this heterocyclic system are discussed and highlighted. The sequential couplings as well as the one‐pot functionalization of two different positions on the imidazo[1,2‐ b ]pyridazine systems are also reviewed. Procedures in which metal‐based catalysis is not involved in the functionalization of imidazo[1,2‐ b ]pyridazines are not included in this review.