Palladium-catalyzed stereoselective ring-opening reaction of aryl cyclopropyl ketones

Herein, we report that ,-unsaturated ketones could be obtained by palladium-catalyzed ring-opening of mono-substituted cyclopropyl ketones efficiently and systematically. ( E )-1-Arylbut-2-en-1-ones were generated from aryl cyclopropyl ketones stereoselectively in yields of 2389% by the Pd(OAc) 2 /PCy 3 catalytic system. The reaction exhibited stereoselectivity (only E products were found) and was suitable for both phenyl and heteroaryl cyclopropyl ketones. The first palladium-catalyzed direct ring-opening of mono-substituted phenyl and heteroaryl cyclopropyl ketones to obtain ,-unsaturated ketones is described. The reaction features high stereoselectivity to obtain ( E )-1-phenylbut-2-en-1-one derivatives.