This reaction also occurs with P(n-Bu)3 and constitutes a very convenient preparation
(developed on a 10 g scale) of K2Fe(CO)4, a non-pyrophoric analogue of the Collman
reagent. In DMAC, or in THF–DMAC mixtures, K2Fe(CO)4 exhibits the same
reactivity as Na2Fe(CO)4 in THF for the carbonylation of reactive alkyl halides [30].