Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5214225 | Tetrahedron | 2016 | 12 Pages |
Abstract
Various 1-methyl-, 1-triisopropylsilyl-, and 1-benzylindoles are carboxylated under CO2 pressure (3.0 MPa) with the aid of 1.0 molar equiv of Me2AlCl to give 1-substituted indole-3-carboxylic acids in good to excellent yields. Mechanistic studies suggest that the intermediate, an indol-3-ylaluminum ate complex, was reversibly formed by electrophilic addition of Me2AlCl to the substrate followed by deprotonation of the resulting adduct. This method is successfully extended to alkoxycarbonylation with ethyl chloroformate and carbamoylation with naphthalen-1-yl isocyanate, which afford ethyl indole-3-carboxylates and N-naphthalen-1-ylindole-3-carboxamides, respectively.
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Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Koji Nemoto, Shinya Tanaka, Megumi Konno, Satoru Onozawa, Masafumi Chiba, Yuuki Tanaka, Yosuke Sasaki, Ryo Okubo, Tetsutaro Hattori,