A simple, efficient, and cheap strategy has been developed for N-arylation of
indoles with hexafloro benzene (1) via incorporating sulfolane as an eco-friendly solvent. NMonopentafluoroarylindole
(3) at ambient conditions and N, N-bistetrafluoroaryl indole (4)
at elevated temperatures were conveniently obtained by simple nucleophilic substitution
using NaOH as the base and sulfolane as a reaction medium to obtain in moderately good
yields, respectively. Subsequently, 3-chloro, 3-bromo, and 3-iodomono-pentafluoroarylindoles
and 3, 3’-dichloro, 3, 3’-dibromo and 3, 3’-diIodobistetrafluoroaryl indoles were
prepared in good yields by using respective halogenating reagents and solvents. All the
chemical transformations were confirmed by analytical tools such as 1HNMR, FR-IR and
HRMS analysis.