Palladium-catalyzed regioselective arylation of an electron-rich olefin byaryl halides in ionic liquids

[GRAPHICS] Palladium-catalyzed arylation of the electron-rich olefin butyl vinyl ether has been accomplished in the ionic liquid 1-butyl-3-methylimidazolium tetr afluoroborate ([bmim][BF4]), using as the arylating agents aryl iodides and bromides instead of the commonly used, but commercially unavailable and ex pensive, aryl triflates. The reaction proceeds with high efficiency and rem arkable regioselectivity, leading almost exclusively to substitution by var ious aryl groups at the olefinic carbon alpha to the heteroatom of butyl vi nyl ether.