Palladium-Catalyzed Intermolecular Acylative Heck Reactions with Imides as Acyl Electrophiles.

We disclose palladium-catalyzed, intermolecular, acylative Heck reactions that use imides as acyl electrophiles. The catalyst generated from [Pd(allyl)Cl]2 and DPEphos promotes the reaction between N-benzoylglutarimides and norbornene in the presence of silver phosphate. The acylative Heck reaction encompasses an array of N-benzoylglutarimide electrophiles that contain electron-donating, halogenated, and electron-withdrawing substituents to generate α,β-unsaturated ketones in moderate to high yields (25-82%). The bicylic α,β-unsaturated ketones are readily transformed into polycyclic architectures via thermal hetero-Diels-Alder reactions that occur by the dimerization of the α,β-unsaturated ketones.