Iodoindenes: Synthesis and application to cross-coupling

Abstract An expeditious synthesis of 5-, 6-, and 7-iodoindenes from the corresponding aminoindan-1-ones in more than 70% yield employing readily available precursors and ubiquitous reagents is reported. The 4-iodoindene has been prepared analogously in 40% overall yield. A three-step sequence involves diazotization-iodination of aminoindan-1-one followed by the reduction and dehydration. The iodoindenes serve as effective substrates for the regioselective Stille coupling with vinyl stannanes but isomeric mixtures are produced during Sonogashira coupling with alkynes in the presence of triethylamine.