Synthesis of Selenopyrano[2,3-c]pyrazol-4(1H)-ones and Their C–H Activation

Abstract

AbstractWe disclose the synthesis of selenopyrano[2,3-c]pyrazol-4(1H)-ones and their aryl derivatives for the first time by using selenopyran ring formation via an in situ-generated selenide that reacts directly with α-halo-β-ynone-bearing substituted pyrazoles to provide the corresponding selenopyrano[2,3-c]pyrazol-4(1H)-ones. Subsequent direct C–H arylation of the latter compounds effected by palladium-catalyzed Heck reactions permits the incorporation of arene substituents onto the selenopyrano[2,3-c]pyrazol-4(1H)-ones scaffolds with moderate to good yields, and might be useful for biological screenings.