Iron trichloride-promoted cyclization of o-alkynylaryl isocyanates: synthesis of 3-(chloromethylene)oxindoles.
Iron trichloride promotes the cationic cyclization of o-(arylethynyl)aryl isocyanates leading to 3-(arylchloromethylene)oxindoles which can be stereoselectively converted to (Z)-3-(aminomethylene)oxindoles under straightforward conditions. When the alkyne is substituted by an alkyl group, activation of the allylic C-H bond also occurs producing 1,2-(dichloroalkylidene)oxindoles.
Cantagrel
Guillaume
G
Laboratoire de Chimie Organique, ESPCI ParisTech, CNRS, 10 rue Vauquelin, 75231 Paris Cedex 05, France.
de Carné-Carnavalet
Benoît
B
Meyer
Christophe
C
Cossy
Janine
J
D002712:Chlorides; D003500:Cyclization; D005290:Ferric Compounds / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D017953:Isocyanates / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D002712:Chlorides; D005290:Ferric Compounds; D007211:Indoles; D017953:Isocyanates; C024555:ferric chloride