American Chemical Society
jo9b03117_si_002.pdf (20.49 MB)

Synthesis of Cyclohepta[b]indoles by (4 + 3) Cycloaddition of 2‑Vinylindoles or 4H‑Furo[3,2‑b]indoles with Oxyallyl Cations

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journal contribution
posted on 2020-02-06, 16:35 authored by Valentina Pirovano, Elisa Brambilla, Andrea Moretti, Silvia Rizzato, Giorgio Abbiati, Donatella Nava, Elisabetta Rossi
The synthesis of cyclohepta­[b]­indole derivatives through the dearomative (4 + 3) cycloaddition reaction of 2-vinylindoles or 4H-furo­[3,2-b]­indoles with in situ generated oxyallyl cations is reported. Oxyallyl cations are generated from α-bromoketones in the presence of a base and a perfluorinated solvent. Cyclohepta­[b]­indole scaffolds are obtained under mild reaction conditions, in the absence of expensive catalysts, starting from simple reagents, in good to excellent yields and with complete diasteroselectivity. Preliminary expansion of the scope to 3-vinylindoles and to aza-oxyallyl cations is reported.