Direct Access to Benzolactams and Benzolactones via Nickel Catalyzed Carbonylation with CO2

Riccardo Giovanelli; Giulia Monda; Sofia Kiriakidi; Carlos Silva López; Giulio Bertuzzi; Marco Bandini

doi:10.1002/chem.202401658

Direct Access to Benzolactams and Benzolactones via Nickel Catalyzed Carbonylation with CO₂

Chemistry. 2024 Aug 22;30(47):e202401658. doi: 10.1002/chem.202401658. Epub 2024 Aug 2.

Authors

Riccardo Giovanelli^{1

2}, Giulia Monda¹, Sofia Kiriakidi^{1

3}, Carlos Silva López³, Giulio Bertuzzi^{1

2}, Marco Bandini^{1

2}

Affiliations

¹ Dipartimento di Chimica "Giacomo Ciamician", Alma Mater Studiorum-Università di Bologna, via P. Gobetti 85, 40129, Bologna, Italy.
² Center for Chemical Catalysis-C3, Alma Mater Studiorum-Università di Bologna, via P. Gobetti 85, 40129, Bologna, Italy.
³ Departamento de Química Orgánica, Universidade de Vigo, AS Lagoas (Marcosende) s/n, 36310, Vigo, Spain.

PMID: 38890146
DOI: 10.1002/chem.202401658

Abstract

A new nickel catalyzed cross-electrophile coupling for accessing γ-lactams (isoindolinones) as well as γ-lactones (isobenzofuranones) via carbonylation with CO₂ is documented. The protocol exploits the synergistic role of redox-active Ni(II) complexes and AlCl₃ as a CO₂ 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 AlCl₃. In particular, the simultaneous transient protection of the pendant amino group of the starting reagents and the formation of the electrophilically activated CO₂-AlCl₃ adduct are shown to concur in paving the way for an energetically favorable mechanistic pathway.

Keywords: CO2; Carbonylation; Cross-electrophile coupling; Lactams; Lewis acids; Nickel catalysis.