Cobalt–Nitrenoid Insertion-Mediated Amidative Carbon Rearrangement via Alkyl-Walking on Arenes

• Published in: Journal of the American Chemical Society Vol. 143; no. 44; pp. 18406 - 18412
• Main Authors: Lee, Jeonghyo, Kang, Bora, Kim, Dongwook, Lee, Jia, Chang, Sukbok
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 10-11-2021
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.1c10138

We herein disclose the Cp*Co­(III)­(LX)-catalyzed amidative alkyl migration using 2,6-disubstituted phenyl azidoformates. Upon the cobalt–nitrenoid insertion toward the substituted ortho carbon, an arenium cationic species bearing a quaternary carbon is generated, and a subsequent alkyl migration process is suggested to occur through an unforeseen alkyl-walking mechanism. A quinolinol ligand of the cobalt catalyst system is proposed to facilitate the final product-releasing rearomatization process by serving as an internal base. This new mechanistic mode enabled both [1,2]- and [1,4]-alkyl rearrangements to allow the structural variation of N-heterocyclic compounds.