Synthesis of Functionalized 1H-Indenes and Benzofulvenes through Iodocyclization of o-(Alkynyl)styrenes

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 a...

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Bibliographic Details
Authors: García García, Patricia; Sanjuán Cortázar, Ana María; Rashid, Muhammad A.; Martínez Cuezva, Alberto; Fernández Rodríguez, Manuel A.; Rodríguez, Félix; Sanz Díez, Roberto
Format: Article
Status:Accepted version
Publication date:2017
Country:España
Institution:Universidad de Burgos (UBU)
Repository:Repositorio Institucional de la Universidad de Burgos (RIUBU)
OAI Identifier:oai:riubu.ubu.es:10259/4530
Online Access:http://hdl.handle.net/10259/4530
Access Level:Open access
Keyword:Química orgánica
Chemistry, Organic
Description
Summary: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.