Oxidative radical cyclisations onto imidazoles and pyrroles using Bu3SnH

Article abstract of DOI:10.1016/S0040-4039(97)10052-1

Oxidative radical cyclisation using Bu₃SnH has been used for the synthesis of [1,2-c]-fused imidazoles and [1,2-a]-fused pyrroles from imidazolecarbaldehydes and acylpyrroles respectively. The intermediate nucleophilic N-alkyl radicals cyclise onto imidazole and pyrrole rings followed by oxidative re-aromatisation.