Cationic Ir(I)-Catalyzed sp³ C-H Bond Alkenylation of Ureas with Alkynes for the Synthesis of 2,3-Disubstituted Indoles - Shibata, Takanori; Hirashima, Hiroyuki; Kasagawa, Mitsugu; Tsuchikama, Kyoji; Endo, Kohei (Synlett, 2011)