The Ni-mediated cyclocarbonylation of allyl halides and alkynes made catalytic. Evidence supporting the involvement of pseudoradical Ni(i) species in the mechanism.

We report here on a highly efficient catalytic method to synthesize intermolecularly the cyclopentane skeleton from starting products as simple as allyl halides, alkynes, and carbon monoxide under very mild reaction conditions by means of a substoichiometric amount of iron, acetone, and a catalytic amount of Ni(II) iodide.