Palladium-catalyzed [3C + 2C + 2C] cycloaddition of enynylidenecyclopropanes: efficient construction of fused 5-7-5 tricyclic systems

Chemical Communications 46(2): 270 - 272 (2010)We report a Pd-catalyzed intramolecular [3C + 2C + 2C] cycloaddition between alkylidenecyclopropanes, alkynes and alkenes. The method provides synthetically relevant 5-7-5 tricyclic structures, with good chemoselectivity and complete diastereoselectivity.This work was supported by the Spanish MICINN [SAF2007-61015, Consolider-Ingenio 2010 (CSD2007-00006)], Xunta de Galicia (PGIDIT06PXIB209126PR and GRC2006/ 132), CSIC and Comunidad de Madrid (CCG08-CSIC/ PPQ3548). BT thanks the Spanish MICINN for a predoctoral fellowship. We thank Johnson-Matthey for the gift of metals.Peer reviewe