A ligand-controlled palladium-catalyzed highly regioselective and diastereodivergent aminomethylative annulation of dienyl alcohols with aminals has been established, which allows for producing either cis- or trans-disubstituted isochromans in good yields with complete regioselectivity and good to excellent diastereoselectivity. Moreover, the chiral cis-products were also obtained in good yields with up to 94% ee by using a chiral phosphinamide as the ligand. Mechanistic studies revealed that the hydroxyl group plays a key role in facilitating the Pd-catalyzed Heck insertion regioselectively taking place across the internal CC bond of conjugated dienes.An efficient hydrogen-bonding assisted directing strategy has been identified, which enables the Pd-catalyzed highly regioselective and diastereodivergent 3,4-difunctionalized aminomethylative annulation of dienyl alcohols with aminals.
