Palladium-Catalyzed Domino Heck/Intermolecular Cross Coupling Reaction for the Synthesis of 3-Alkyl Substituted Indene Derivatives

Indene derivatives are one of the core skeletons of many natural products and drugs, and are widely used in medicine, materials and other fields.It is of great significance to develop a simple and efficient method for the synthesis of indene derivatives.In this work, iodobenzenes with proximity linking unactivated olefins undergo palladium-catalyzed intramolecular Heck reaction to generate alkylpalladium(II) intermediates, which induce the intramolecular nucleophilic cyclization of 2-(2-phenylethynyl)phenylmalonate diethyl ester to afford a series of 3-alkyl substituted indene derivatives.The reaction has the advantages of mild conditions, simple operation, high yield and wide applicability of substrates, which provides a new strategy for the synthesis of indene derivatives.