Electroreductive Intermolecular Coupling of 3‑Methoxycarbonylindoles with Ketones
datasetposted on 07.06.2013, 00:00 by Naoki Kise, Akinori Sueyoshi, Shin-ichirou Takeuchi, Toshihiko Sakurai
The electroreductive coupling of 1-alkoxycarbonyl-3-methoxycarbonylindoles with aromatic ketones in the presence of chlorotrimethylsilane gave cis-adducts stereoselectively. The cis-adducts were readily transformed to trans-adducts by treatment with catalyst DBU. On the other hand, the electroreductive coupling of 1-methyl-3-methoxycarbonylindole with aliphatic ketones in isopropanol afforded trans-adducts exclusively. The adducts are the precursors for the synthesis of 2-substituted 3-methoxycarbonylindoles and indolines.