A facile and general method for regioselective C2 sulfonylation reaction of indoles mediated by iodine is described. The 2-sulfonylated products were obtained up to 96% yield under mild reaction conditions (room temperature, 2 h).

The first general examples of direct coupling of heteroaryl chlorides, especially substituted 2-pyridyl chlorides which were previously found to be problematic, with electron-deficient polyfluoroarenes are reported. Pd(OAc)2 associated with 3-(dicyclohexylphosphino)-2-phenylindole L1 serves as the effective catalyst which allows the challenging direct coupling of heteroaryl chlorides and polyfluoroarenes. In addition to heterocycles, a wide range of non-activated and activated aryl chlorides and alkenyl chlorides were also applicable under this catalyst system. A catalyst loading down to 1 mol % Pd can be achieved.

Regioselective C2 Sulfonylation of Indoles Mediated by Molecular Iodine. -No product is obtained for the reaction of Tol-SO 2 Na with N-protected indoles, including N-Cbz, N-Bz, N-Mes. -(KATRUN, P.; MUEANGKAEW, C.; POHMAKOTR, M.; REUTRAKUL, V.; JAIPETCH, T.; SOORUKRAM, D.; KUHAKARN*, C.; J. Org. Chem. 79 (2014) 4, 1778-1785, http://dx.

Chlorides Catalyzed by Palladium Indolylphosphine Complexes -[under mild reaction conditions and a catalyst loading down to 1 mol% Pd]. -(YUEN, O. Y.; CHAROENSAK, M.; SO, C. M.; KUHAKARN, C.; KWONG*, F. Y.; Chem. -Asian J. 10 (2015) 4, 857-861, http://dx.