Palladium-catalyzed site-selective direct olefination of 6-electron-withdrawing group substituted 3-arylbenzo[d]isoxazoles

A palladium-catalyzed direct olefination of 6-electron-withdrawing group substituted 3-arylbenzo[d]isoxazoles has been developed with exclusive site-selectivity and excellent E-stereoselectivity. It was found that the olefination occurred at the acidic C-7 position only, overriding a potential directing-group assisted bias. With the wide range of alkene patterns, the protocol allows convenient access to multifarious C-7 olefinated benzo[d]isoxazoles in moderate to good yields.