Pd(II)-Catalyzed Asymmetric Addition of Arylboronic Acids to Isatin-Derived Ketimines

A Pd(II)/Pyrox-catalyzed enantioselecitve addition of arylboronic acids to 3-ketimino oxindoles was developed, providing chiral 3-amino-2-oxindoles with a quaternary stereocenter in high yields and with good enantioselectivities. A variety of functionalized 3-ketimino oxindoles can be used, and the method tolerates some variation in arylboronic acid scope. This asymmetric arylation provides an alternative efficient catalytic method for the preparation of chiral 3-aryl-3-amino-2-oxindoles, which also represents the first example of a Pd(II)-catalyzed addition of arylborons to exocyclic ketimines.