Useful, regioflexible methods for functionalization of 1-phenylpyrrole derivatives

Highly regioselective mono-, di- and tribrominations of 1-[2-(trifluoromethyl)phenyl]-1H-pyrrole and several derivatives were accomplished with N-bromosuccinimide under mild conditions. Combined applications of these brominations with organometallic (e.g., bromine/lithium exchange or metalation) reactions provided a novel regioflexible route to new multifunctionalised 1-phenylpyrrole derivatives. The structures of the new products were determined by spectroscopic methods and confirmed in three cases with single crystal X-ray diffraction measurements.