Inverse Electron-Demand Aza-Diels–Alder Reaction of Cyclic Enamides with 1,2-Diaza-1,3-dienes in Situ Generated from α-Halogeno Hydrazones: Access to Fused Polycyclic Tetrahydropyridazine Derivatives
Li‐Wen Shen, Tingting Li, Yong You, Jian‐Qiang Zhao, Zhen‐Hua Wang, Wei‐Cheng Yuan
Abstract
An efficient inverse electron-demand aza-Diels-Alder reaction of cyclic enamides and 1,2-diaza-1,3-dienes, which could be readily formed in situ from α-halogeno hydrazones and a base, has been successfully developed. With the developed approach, a wide range of fused polycyclic tetrahydropyridazines were smoothly obtained in up to 99% yield under benign reaction conditions. This reaction concept was also extended to acyclic enamide substrates for accessing 1,4,5,6-tetrahydropyridazines. A gram-scale experiment and further derivatizations of the polycyclic tetrahydropyridazine products were also conducted to verify the practicability of the methodology.
Topics & Concepts
ChemistryYield (engineering)InverseDiels–Alder reactionCombinatorial chemistryIn situOrganic chemistryCatalysisGeometryMetallurgyMathematicsMaterials scienceSynthesis and Catalytic ReactionsClick Chemistry and ApplicationsSynthesis and Biological Evaluation