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.