Publications > García-García et al
Synthesis of Functionalized 1H-Indenes and Benzofulvenes through Iodocyclization of o-(Alkynyl)styrenes.
1. Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá , 28871 Alcalá de Henares, Madrid, Spain. 2. Área de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos , Pza. Misael Bañuelos s/n, 09001 Burgos, Spain. 3. Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo , C/Julián Clavería, 8, 33006 Oviedo, Spain.
Abstract
A convenient method for the preparation of synthetically useful 3-iodoindene derivatives has been developed. This protocol, based on the 5-endo iodocyclization reaction of o-(alkynyl)styrenes, represents one of the scarce examples of halocyclizations using olefins as nucleophilic counterparts and allows the synthesis of both 3-iodo-1H-indenes (from β-alkyl-β-alkyl/aryl-o-(alkynyl)styrenes) and 3-iodobenzofulvenes (from β,β-diaryl-o-(alkynyl)styrenes) in good yields under mild reaction conditions. In addition, related alkoxyiodocyclization processes are described, which are particularly interesting in their intramolecular version because they allow the synthesis of heteropolycyclic structures containing the indene core. Finally, the usefulness of the prepared 3-iodoindenes has been demonstrated by the synthesis of several polysubstituted indene derivatives through conventional palladium-catalyzed cross-coupling reactions and iodine-lithium exchange processes.