Ni-Catalyzed CarbonylativeFour-Component SpirocyclizationCascade of BCB-Tethered Allyl Amides and Esters

A Ni-catalyzed four-component spirocyclization/carbonylation cascade involving a [π + σ] system is presented. Various BCB-tethered allyl amides (or esters) readily reacted with activated alkyl halides and arylboronic acids under atmospheric CO pressure to afford highly functionalized spirocyclobutyl γ-lactams (or lactones) in good yields. This cascade efficiently forms four C–C bonds in one step and features a broad substrate scope and functional group tolerance. Moreover, the ease of large-scale synthesis and versatile derivatizations highlight its significant potential for applications in organic synthesis.