Rhodium(I)-Catalyzed

The regiospecific introduction of substituents into the 4-position of 2,3-dihydroindoles (indolines), which is significant for the synthesis of various natural products and pharmaceuticals, was achieved by rhodium(I)-catalyzed cyclotrimerizations of 1 with acetylene to give 2. Up to four substituents can be introduced simultaneously into the indoline core by using this novel strategy. R=OH, OBzl, Otetrahydropyranyl, NHSO(2)C(6)H(4)CH(3); Ts=H(3)CC(6)H(4)SO(2).