Synthesis of 3,3-disubstituted oxindoles by one-pot integrated Brønsted base-catalyzed trichloroacetimidation of 3-hydroxyoxindoles and Brønsted acid-catalyzed nucleophilic substitution reaction.
Treatment of 3-hydroxyoxindoles with trichloroacetonitrile (1.3 equiv.) and a catalytic amount of DBU (0.1 equiv.) followed by addition of nucleophiles (1.5 equiv.) and diphenylphosphoric acid (0.2 equiv.) afforded the 3,3-disubstituted oxindoles in good to excellent yields. DFT computations supported the notion that the reaction went through the 1-alkyl-2-oxo-2H-indol-1-ium intermediate.
Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, CH-1015 Lausanne, Switzerland.
Cyril
C
Piemontesi
Qian
Q
Wang
Jieping
J
Zhu
D000143:Acids / Q000737:chemistry*; D002384:Catalysis; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D011789:Quantum Theory; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry
D000143:Acids; D007211:Indoles; D014508:Urea; C483182:N,N'-dibutylurea