Pyrrole Formation via Reactivity of η4-(Vinylketenimine)iron Complexes with Electron-Deficient Alkynes

When electron-deficient alkynes reacted with η4-(vinylketenimine)iron complexes, pyrroles were produced. Pyrrole formation involved the [2 + 3] cycloaddition of alkyne to the ketenimine moiety, migration of the vinyl group, and decomplexation. Either alkynes bearing two electron-withdrawing groups, or terminal alkynes with an electron-withdrawing group reacted to generate pyrroles