康 · 学术 | Reaction of the Day No. 1770

Visible-Light-Mediated Skeletal Editing of Furans to Pyridazines

Lu-Lu Qin,1 Yan Lei,1 Yihan Tang,2* and Peng-Ju Xia1*

1School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China; 2Department of Chemistry, Chung-Ang University, Seoul 06974, Republic of Korea; 

—Org. Lett., 2026, 28, 12599?12603.

Recommended by Bingbing Chang_MC5

KEY WORDS: photo chemistry, skeletal editing (反应类型), C(sp2)-N  (成键类型), furans, hydrazine hydrate (原料), pyridazines (产物)

ABSTRACT: Prof. Peng-Ju Xiaet al. describe a visible-light-mediated skeletal editing of furans to pyridazines via formal O-to-NN atom-pair exchange using hydrazine hydrate. The reaction proceeds under metal-free conditions at room temperature in air, providing di-, tri-, and tetrasubstituted pyridazines with complete regiocontrol from readily available furans. Broad functional-group tolerance, gram-scale synthesis, and late-stage skeletal editing of complex molecules are demonstrated. Mechanistic studies suggest that water suppresses hydrazine-mediated quenching of the excited photocatalyst, while additional experiments support the involvement of oxygen-derived reactive species in the overall transformation.

Development of Furan Skeletal Editing and Design of This Work

Substrate Scope of Furans

Proposed Reaction Pathways and Energy Profile

(A) Late-Stage Modification of Complex Molecules; (B) Late-Stage Diversification of Bioactive Molecules and Pharmaceuticals

Summary and Comments

Prof. Peng-Ju Xia et al. have developed a visible-light-mediated skeletal editing of furans to pyridazines through a formal O-to-NN atom-pair exchange using hydrazine hydrate. The transformation proceeds under mild, metal-free conditions with broad substrate scope and enables late-stage skeletal editing of complex molecules. Mechanistic studies suggest that water modulates competing excited-state quenching processes, while oxygen-derived reactive species participate in the overall transformation. This work expands the scope of photochemical skeletal editing and provides a practical approach to highly substituted pyridazines from readily available furans.