Rh(III)-Catalyzed [3 + 2] Annulation of Aniline Derivatives with Vinylsilanes <i>via</i> C–H Activation/Alkene Cyclization: Access to Highly Regioselective Indoline Derivatives

The Rh­(III)-catalyzed reaction of aniline derivatives that contain a pyrimidine directing group with vinylsilanes results in the formation of C3-substituted indoline derivatives in a highly regioselective manner via a C–H activation/alkene cyclization cascade. The results of the mechanistic experiments indicate that C–H bond cleavage is not the rate-determining step and that the reaction proceeds via the formation of a six-membered rhodacycle as a key catalytic species through a pyrimidine-directed electrophilic ortho-C–H rhodation.