Palladium-Catalyzed Cascade Reaction Involving Cyclopropenones Enables Construction of Heterocycle-Containing γ-alkylidenebutenolides

A novel palladium-catalyzed cascade reaction process for the diverse synthesis of heterocycle-containing γ-alkylidenebutenolide frameworks has been developed. Using this protocol, γ-alkylidenebutenolide and δ-heterocycle units can be constructed simultaneously through one-pot multiple C-C/C-O bond formation of different iodoaryl-substituted alkenes with cyclopropenones, leading to nine types of heterocycle-containing γ-alkylidenebutenolides in generally acceptable yields. The advantage of this work is also featured by its gram-scale preparation, further diverse transformations, and good <i>in vitro</i> antitumor activities of the highly valuable and modifiable synthetic products.