Cationic Ir(I)-Catalyzed sp3 C-H Bond Alkenylation of Ureas with Alkynes for the Synthesis of 2,3-Disubstituted Indoles

Secondary sp(3) C-H bond activation of ureas was achieved by a cationic Ir(I)-JOSIPHOS catalyst. Regioselective C-H bond cleavage adjacent to the nitrogen atom in N-benzylureas and an N-allyl urea possessing a 2-alkynylphenyl group, and subsequent intramolecular reaction with an alkyne along with double-bond isomerization provided 2,3-disubstituted indoles.