Rh-Catalyzed Decarbonylative Coupling with Alkynes via C–C Activation of Isatins

Herein
we report a [5 + 2 – 1] transformation though catalytic
decarbonylative coupling between isatins and alkynes, which provides
a unique way to synthesize 2-quinolinone derivatives. A broad range
of alkynes can be coupled efficiently with high regioselectivity.
This reaction is proposed to go through C–C activation of isatins,
followed by decarbonylation and alkyne insertion. Directing group
(DG) plays a critical role in this transformation. Assisted by the
DG, the C–C cleavage of isatins occurs at room temperature.