title: Synthetic access to poly-substituted 6-alkoxyindoles from 1,3-cyclohexanediones and nitroolefins through facile aromatization reaction.
abstract: 6-Alkoxy-3-arylindoles were efficiently prepared from 1,3-cyclohexanedione enol ethers and beta-nitrostyrenes. Michael addition using the kinetically generated enolate, followed by Zn reduction of a nitro group of the resulting adducts produced the nitrones which were then treated with acetic anhydride to induce aromatization by dehydration and N-acetylation, which furnished the desired indoles by the DDQ oxidation. This methodology provides an easy entry toward various poly-substituted 6-alkoxyindoles.
authors.affiliation: Department of Medicinal and Bioengineering Science, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.
authors.forename: Li-Jian
authors.initials: LJ
authors.lastname: Ma
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Li
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Kusuyama
authors.forename: Ibrahim El-Tantawy
authors.initials: Iel-T
authors.lastname: El-Sayed
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Inokuchi
mesh_terms: D000475:Alkenes / Q000737:chemistry; D003512:Cyclohexanones / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry; D006841:Hydrocarbons, Aromatic / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis*; D008722:Methods; D009574:Nitro Compounds / Q000737:chemistry*; D013343:Styrenes / Q000737:chemistry
chemical_list: D000475:Alkenes; D003512:Cyclohexanones; D004987:Ethers; D006841:Hydrocarbons, Aromatic; D007211:Indoles; D009574:Nitro Compounds; D013343:Styrenes; C004636:1,3-cyclohexanedione