N- and C-Arylations of Oxindoles: Orthogonal Selectivity of Pd and Cu Catalysts

Significance

In oxindoles the protons in the positions C3 and N1 have identical acidities due to a mesomeric stabilization effect. In this article, two catalytic systems based on Pd and Cu with orthogonal chemoselectivity were introduced. The Pd-catalyzed reaction cleanly furnishes the C-arylated products, whereas employing the copper catalyst leads to the respective N-arylated oxindoles. Complementing computational studies offer insights into the respective mechanisms.