Synthesis of substituted 3-iodopyrroles by cycloisomerization of propargylic aziridines with iodine

The electrophilic cyclizations of N-substituted propargylic aziridines are described. 3-Iodopyrroles having a variety of substituents at the 2- and 3-positions were synthesized by reacting propargylic aziridines with iodine. Whereas N-tosyl-substituted substrates require a platinum catalyst to promote the reaction, the iodine-promoted cycloisomerizations proceed when N-benzyl-substituted substrates are employed.