The organophosphine catalyzed reaction of activated alkynes with isocyanides produces the corresponding heteroaromatization products, pyrroles, regioselectively in good yields. The reaction proceeds most probably through the 1, 4-addition of the nucleophilic phosphine catalyst to the alkynes, followed by a [3+ 2] cycloaddition between the resulting alkenyl phosphine intermediates and a carbanion derived from the isocyanides.
