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 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.

Synthesis of 1H-Isoindole-Containing Scaffolds Enabled by a Nitrile Trifunctionalization

“…Carbene-alkyne metathesis (CAM) stands out as a potent transformation for the in situ generation of vinyl metal carbene intermediates, particularly providing access to donor–donor carbenes that are dangerous to obtain directly from diazo compounds and whose reactivity is less explored . In the course of our project aimed at the development of molecular complexity through the reaction of in situ generated vinyl metal carbenes, we decided to explore whether a simple propargyl diazoacetate model was amenable to a CAM/nitrile ylide formation/1,7-electrocyclization reaction (Scheme C). Numerous challenges were faced, including difficulties in controlling the cascade order of the events and favoring the intermolecular reaction with the nitrile.…”