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Electrooxidative Rhodium-Catalyzed [5+2] Annulations via C-H/O-H Activations.

ABSTRACT: Electrooxidative annulations involving mild transition metal-catalyzed C-H activation have emerged as a transformative strategy for the rapid construction of five- and six-membered heterocycles. In contrast, we herein describe the first electrochemical metal-catalyzed [5+2] cycloadditions to assemble valuable seven-membered benzoxepine skeletons by C-H/O-H activation. The efficient alkyne annulation featured ample substrate scope, using electricity as the only oxidant. Mechanistic studies provided strong support for a rhodium(III/I) regime, involving a benzoxepine-coordinated rhodium(I) sandwich complex as the catalyst resting state, which was re-oxidized to rhodium(III) by anodic oxidation.

SUBMITTER: Wang Y

PROVIDER: S-EPMC7986427 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Electrooxidative Rhodium-Catalyzed [5+2] Annulations via C-H/O-H Activations.

Wang Yulei Y Oliveira João C A JCA Lin Zhipeng Z Ackermann Lutz L

Angewandte Chemie (International ed. in English) 20210208 12

Electrooxidative annulations involving mild transition metal-catalyzed C-H activation have emerged as a transformative strategy for the rapid construction of five- and six-membered heterocycles. In contrast, we herein describe the first electrochemical metal-catalyzed [5+2] cycloadditions to assemble valuable seven-membered benzoxepine skeletons by C-H/O-H activation. The efficient alkyne annulation featured ample substrate scope, using electricity as the only oxidant. Mechanistic studies provid ...[more]

PMID: 33471952

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