Miyakoshi T, Niggli NE, Baudoin O. Remote Construction of N-Heterocycles via 1,4-Palladium Shift-Mediated Double C-H Activation.
Angew Chem Int Ed Engl 2022;
61:e202116101. [PMID:
35143094 PMCID:
PMC9303548 DOI:
10.1002/anie.202116101]
[Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Indexed: 12/14/2022]
Abstract
In the past years, Pd0‐catalyzed C(sp3)−H activation provided efficient and step‐economical methods to synthesize carbo‐ and heterocycles via direct C(sp2)−C(sp3) bond formation. We report herein that a 1,4‐Pd shift allows access to N‐heterocycles which are difficult to build via a direct reaction. It is shown that o‐bromo‐N‐methylanilines undergo a 1,4‐Pd shift at the N‐methyl group, followed by intramolecular trapping by C(sp2)−H or C(sp3)−H activation at another nitrogen substituent and remote C−C bond formation to generate biologically relevant isoindolines and β‐lactams. The product selectivity is influenced by the employed ligand, with NHCs favoring the product of remote C−C coupling against products arising from direct C−C coupling and N‐demethylation.
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