Catalyst-Controlled Chemodivergent Carbene Transfer Reactions With Bicyclo[1.1.0]butane-Derived Acceptor Metallocarbenes.

)─H insertion to access allyl oxindoles. Both protocols exhibit broad substrate scope, high functional group tolerance, and exceptional atom economy, and their synthetic utility is highlighted through the preparation of core structures of bioactive compounds. Computational and experimental studies reveal that Ni-carbene generation proceeds via a stepwise dual C─C cleavage, contrasting with the concerted dual cleavage and subsequent electrophilic aromatic substitution manifold established for the copper system.