Palladium/Acid Relay Catalyzed Tandem Heck Coupling/6-Endo Cyclization between ortho-Halogenated Benzoates and Unactivated Terminal Alkenes for the Synthesis of 1-Isochromanones

We report a unique and expeditious route to synthesize 1-isochromanone derivatives through palladium catalyzed tandem Heck coupling/6-endo hydroacyloxylation cyclization between readily available ortho-halogenated benzoates and unactivated alkenes. Various 2-bromo or 2-iodo benzoates can be coupled efficiently with a broad range of alkenes to afford functionalized 1-isochromanones in high yields. Significantly, this cost-efficient and easy-to-handle synthetic methodology will have great prospect application in the synthetic and medicinal chemistry.