Diversified Construction of Benzothiophene-Fused Pyridazinone via a Skeletal Editing and Pyridine Migration Domino Process and DFT Studies

Skeletal editing has emerged as a highly valuable strategy for the precise and efficient modification of cyclic frameworks. However, its application in divergent synthesis and domino reactions remains underexplored. In this study, we report an efficient domino reaction for the synthesis of benzothiophene-fused pyridazinone. These domino reactions encompass both skeletal editing and pyridine migration. Moreover, by modulating the substrate structure, we can achieve pyridine 1,2-migration, which proceeds through a ring-opening/ring-closing skeletal editing process rather than a direct shift between two nitrogen atoms, a conclusion supported by both controlled experiments and DFT calculations. Furthermore, based on DFT calculations, we can also achieve a potential pyridine 1,5-migration.