Intramolecular Interception of the Remote Position of Vinylcarbene Silver Complex Intermediates by C(sp3)−H Bond Insertion

Àlex Díaz-Jiménez,Roger Monreal-Corona,Albert Poater,María Álvarez,Elena Borrego,Pedro J. Pérez,Ana Caballero,Anna Roglans,Anna Pla-Quintana

Angew. Chem. Int. Ed. 2022,

The trapping of the elusive vinylogous position of a vinyl carbene with an aliphatic Csp3-H bond has been achieved for the first time during a silver-catalyzed carbene/alkyne metathesis (CAM) process. A Tpx-containing silver complex first promotes the generation of a donor-acceptor silver carbene which triggers CAM, generating a subsequent donor-donor vinyl silver carbene species, which then undergoes a selective vinylogous C(sp3)-H bond insertion, leading to the synthesis of a new family of benzoazepines. Density functional theory (DFT) calculations unveil the reaction mechanism, which allows proposing that the C-H bond insertion reaction takes place in a stepwise manner, with the hydrogen shift being the rate determining step.