Palladium/zinc co-catalyzed syn-stereoselectively asymmetric ring-opening reaction of oxabenzonorbornadienes with phenols

A new palladium/zinc co-catalyst system associated with chiral (R)-Difluorphos for asymmetric ring-opening reaction of oxabenzonorbornadienes with phenols is reported. This catalyst system allows the formation of cis-2-aryloxy-1,2-dihydronaphthalen-1-ol products in good yields (up to 95-% yield) with excellent enantioselectivities (up to 99-% ee). The cis-configuration of the product has been confirmed by X-ray crystal structure analysis. To the best of our knowledge, it represents the first example in ring-opening reactions of bicycloalkenes with heteronucleophiles in a syn-stereoselective manner. Open the ring: A new palladium/zinc co-catalyst associated with chiral (R)-Difluorphos for asymmetric ring-opening reaction of oxabenzonorbornadienes with phenolic or naphtholic nucleophiles was developed, which afforded the corresponding cis-2-aryloxy-1,2-dihydronaphthalen-1-ol products in good yields (up to 95-% yield) with excellent enantioselectivities (up to 99-% ee).