Transformable Transient Directing Group-Assisted C(sp 2 )-H Activation: Synthesis and Late-Stage Functionalizations of o -Alkenylanilines.

The isocyanate group in aryl isocyanates serves as a transformable transient directing group in a Ru(II)-catalyzed ortho olefination leading to o -alkenylanilines. In alcoholic solvents, aryl isocyanates are transformed into carbamates, which initiate the insertion of acrylates via o -C-H activation. In particular, t AmOH serves the dual role of solvent-cum transient directing mediator. The o -alkenylanilines are converted into azacoumarins and subsequently into C-4 aryl-substituted azacoumarins using aryl iodides as coupling partners via Pd(II)-catalyzed C-H functionalizations.