Synthesis of Indole and Biindolyl Triflones: Trifluoromethanesulfonylation of Indoles with Tf2O/TTBP (2,4,6-Tri-tert-butylpyridine) System.

A convenient synthesis of indole triflones is reported. N-Alkyl, aryl and N-H indole triflones were obtained in 82–96% yields by the Tf2O/TTBP System. Biindolyl triflones were accessed in 51–81% yields for the first time by simple treatment of the resulting indole triflones with a base and without any use of organometallic chemistry. An environmentally friendly solvent, Solkane 365/227, can be substituted for this process without any loss of efficiency.