The article presents a novel method for skeletal editing of pyridines, enabling the precise substitution or rearrangement of atoms in the core ring structures of complex molecules. This approach involves a one-pot sequence of sequential dearomatization, cycloaddition, and rearomatizing retrocycloaddition reactions, which transform pyridines into benzenes and naphthalenes with diversified substituents. The method is modular and can be applied to late-stage skeletal diversification of pyridine cores in drugs. The authors demonstrate the effectiveness of this strategy through the synthesis of various substituted benzenes and naphthalenes, showing excellent regioselectivity and broad substrate scope. The practicality of the method is illustrated by its successful application in drug modification and fragment coupling of complex molecules. The study also includes theoretical calculations to explain the reaction mechanisms and regioselectivity.The article presents a novel method for skeletal editing of pyridines, enabling the precise substitution or rearrangement of atoms in the core ring structures of complex molecules. This approach involves a one-pot sequence of sequential dearomatization, cycloaddition, and rearomatizing retrocycloaddition reactions, which transform pyridines into benzenes and naphthalenes with diversified substituents. The method is modular and can be applied to late-stage skeletal diversification of pyridine cores in drugs. The authors demonstrate the effectiveness of this strategy through the synthesis of various substituted benzenes and naphthalenes, showing excellent regioselectivity and broad substrate scope. The practicality of the method is illustrated by its successful application in drug modification and fragment coupling of complex molecules. The study also includes theoretical calculations to explain the reaction mechanisms and regioselectivity.