Versatile synthesis of polyfunctionalized carbazoles from (3-iodoindol-2-yl)butynols via a gold-catalyzed intramolecular iodine-transfer reaction

The controlled gold-catalyzed preparation of 3-iodo 2,4,6-trisubstituted 9H-carbazoles has been developed by starting from (3-iodoindol-2-yl)butynols. These results could be explained through an initial 6-endo-dig alkyne carbocyclization by chemo- and regiospecific attack of the C3-indole position a...

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Detalles Bibliográficos
Autores: Alcaide, Benito, Almendros, Pedro, Alonso, J. M., Busto, Eduardo, Fernández, I., Ruiz, M. P., Xiaokaiti, G.
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/117771
Acceso en línea:http://hdl.handle.net/10261/117771
Access Level:acceso abierto
Palabra clave:Density functional calculations
Cyclization
Gold
Iodine
Alkynes
Descripción
Sumario:The controlled gold-catalyzed preparation of 3-iodo 2,4,6-trisubstituted 9H-carbazoles has been developed by starting from (3-iodoindol-2-yl)butynols. These results could be explained through an initial 6-endo-dig alkyne carbocyclization by chemo- and regiospecific attack of the C3-indole position at the external alkyne carbon followed by a stepwise 1,3-iodine transfer and dehydration. This reaction outcome for the gold-catalyzed transformation of (3-iodoindol-2-yl)alkynols sharply contrasts with that observed for conventional metal-catalyzed processes of iodoarenes, because iodine transfer is feasible. This selective reaction has been studied experimentally; additionally, its mechanism has been investigated by means of density functional theory calculations.