Trapping σ‐Alkyl–Palladium(II) Intermediates with Arynes Encompassing Intramolecular C−H Activation: Spirobiaryls through Pd‐Catalyzed Cascade Reactions

A palladium‐catalyzed cascade reaction based on the trapping of transient alkyl–Pd II intermediates with arynes encompassing a C−H activation step has been developed. This synthetic pathway gives rise to hetero‐spirocyclic scaffolds containing a biaryl motif, and opens up new synthetic strategies in the design of cascade reactions since it gathers several aspects of Pd chemistry, i.e., intra‐ and intermolecular carbopalladation of unsaturated species, C−H activation and C−C coupling processes.