Indium triflate catalyzed microwave-assisted alkenylation of methoxyphenols: synthesis of indenes and chromenesDedicated to Prof. H. Ila on her 71st birthday.Electronic supplementary information (ESI) available. Copies of 1H NMR and 13C NMR spectra of 4a-e and 5a-j and COSY, HSQC and HMQC spectra of 5i. CCDC 1418487 and 1418498. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ob01734c

In(OTf) 3 catalyzed microwave-assisted alkenylation of methoxyphenols was investigated. Exclusive formation of either indenes or chromenes was observed depending on the position of the methoxy group on phenol. The structures of 1 H -inden-4-ol derivatives ( 4a-e ) and 4 H -chromene derivatives ( 5a-j ) were established by NMR ( 1 H & 13 C) and high-resolution mass spectra, which were further supported by single crystal X-ray analysis of 4c and 5a . In(OTf) 3 catalyzed microwave-assisted alkenylation of methoxyphenols was investigated.