Palladium‐Catalyzed Site‐Selective [3+2] Annulation via Benzylic and <i>meta</i> C−H Bond Activation
Qiyuan He, Naoto Chatani
Abstract
The palladium-catalyzed [3+2] annulation of aromatic amides with maleimides via the activation of ortho benzylic C-H and meta C-H bonds is reported. Carboxamide and anilide type substrates that contain a 2-methylthiophenyl group both participate in this [3+2] annulation, indicating that the presence of a 2-methylthiophenyl directing group is a key for the success of the reaction. The first C-H bond activation at the benzylic C-H bond is followed by a second C-H bond activation at the meta C-H bond to give five-membered cyclic products. The cleavage of these C-H bonds is irreversible.
Topics & Concepts
AnnulationChemistryPalladiumCatalysisBond cleavageStereochemistryCleavage (geology)Medicinal chemistryOrganic chemistryMaterials scienceComposite materialFracture (geology)Catalytic C–H Functionalization MethodsCatalytic Cross-Coupling ReactionsSynthesis and Catalytic Reactions