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

Abstract

The trapping of the elusive vinylogous position of a vinyl carbene with an aliphatic C(sp³ )-H bond has been achieved for the first time during a silver-catalyzed carbene/alkyne metathesis (CAM) process. A Tp^x -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.

Keywords: 1-Benzoazepine; Carbene-Alkyne Metathesis; C−H Bond Insertion; Silver Catalysis; Vinylogous Reactivity.