1. In(ONf)3-catalyzed 7-membered carbon-ring-forming annulation of heteroarylindoles with α,β-unsaturated carbonyl compounds
- Author
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Naoki Saegusa, Teruhisa Tsuchimoto, Takumi Hayashi, Mana Osano, Kazuhiro Sambai, Tomohiro Tani, and Takahiro Johshita
- Subjects
chemistry.chemical_classification ,Annulation ,Alicyclic compound ,chemistry ,Organic Chemistry ,chemistry.chemical_element ,Halogenation ,Medicinal chemistry ,Indium ,Catalysis - Abstract
A seven-membered carbon-ring-forming annulation occurred, upon treatment of heteroarylindoles with α,β-unsaturated carbonyl compounds in the presence of an indium catalyst. The reductive annulation was observed when octylsilane was used. With 1,3-dibromo-5,5-dimethylhydantoin instead of octylsilane, the oxidative annulation proceeded. These two reactions were completely controlled; this is the first achievement in the biheteroaryl-based seven-membered carbon-ring-forming annulation. Tetracyclic products obtained from the oxidative annulation underwent SEAr-based bromination regioselectively. The resulting Br–C bond was used for the palladium-catalyzed Suzuki–Miyaura cross-coupling reaction to extend the π-conjugated region. Reaction pathways were also discussed based on some mechanistic studies.
- Published
- 2021