Regioselective Dual Gold/Silver-Catalyzed C3-H Alkynylation of Triazolopyridazines
Na Wang1, Junxiao Huo1, Yufan Zhang1
1Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, P. R. China.
Abstract:
A regioselective C3-H alkynylation of triazolopyridazines has been achieved via dual gold/silver catalysis employing hypervalent iodine(III) reagents. The transformation proceeds through an alkynyl Au(III) intermediate and a silver-assisted C-H activation pathway, delivering a broad range of 3-alkynylated triazolopyridazines in good to excellent yields. Mechanistic studies, including H/D exchange experiments, reveal that the silver species plays a crucial role in facilitating C-H activation. The reaction is readily scalable to gram quantities, and the resulting products can be further diversified to access structurally related derivatives.
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