Cationic Iridium Complex-Catalyzed Intermolecular Hydroalkylation of Unactivated Alkenes with 1,3-Diketones.

Intermolecular hydroalkylation of unactivated terminal alkenes with 1,3-diketones under neutral conditions has been achieved using a cationic iridium catalyst. An active C-H bond of 2,4-pentadione (2a) added to 1-octene (1a) under refluxing DCE to give a Markovnikov product in 88% yield. A broad scope of alkenes and 1,3-diketones was observed. The products were easily converted to heterocycles. This reaction provides a new method for extending a carbon chain from an unactivated aliphatic terminal alkene.