Bismuth(III) Triflate Catalyzed Condensation of Isatin with Indoles and Pyrroles: A Facile Synthesis of 3,3-Diindolyl- and 3,3-Dipyrrolyl Oxindoles - Yadav, Jhillu S; SubbaReddy, Basireddy V; Gayathri, Kamakolanu Uma; Meraj, Syeda; Prasad, Attaluri R (Synthesis, 2006)