Access to Polysubstituted Pyrimidin-2-ones by Pd-Catalyzed [2 + 2 + 2] Cycloaddition of Alkyne-Tethered
Xing-Zhen Wang1, Xu-Dong Hu1, Wen-Bo Liu1,2
1Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
Abstract:
Transition-metal-catalyzed [2 + 2 + 2] cycloaddition reactions of alkynes, nitriles, and other π partners have been recognized as economic strategies to assemble aza-six-membered rings, but access to pyrimidin-2-ones is not disclosed. Herein, we report a palladium-catalyzed [2 + 2 + 2] cycloaddition of 1,3-diyne-substituted malononitriles and isocyanates for the construction of polysubstituted pyrimidin-2-ones. This reaction features a broad substrate scope and moderate to high yields. Conjugated pyrimidin-2-one acting as a fluorophore showcased potential as a fluorescent chemosensor for Fe(III) detection.
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