Direct Access to Benzolactams and Benzolactones via Nickel Catalyzed Carbonylation with CO 2

A new nickel catalyzed cross-electrophile coupling for accessing γ-lactams (isoindolinones) as well as γ-lactones (isobenzofuranones) via carbonylation with CO is documented. The protocol exploits the synergistic role of redox-active Ni(II) complexes and AlCl as a CO activator/oxygen scavenger, leading to the formation of a wide range of cyclic amides and esters (28 examples) in good to high yields (up to 87 %). A dedicated computational investigation revealed the multiple roles played by AlCl . In particular, the simultaneous transient protection of the pendant amino group of the starting reagents and the formation of the electrophilically activated CO -AlCl adduct are shown to concur in paving the way for an energetically favorable mechanistic pathway.