The mechanism of organometallic migration reactions. A configuration mixing (CM) approach

The configuration mixing (CM) model is applied to the migratory insertion of carbon monoxide into a transition metalcarbon bond. A qualitative reaction profile for the reaction is constructed using an energy plot of the three electronic configurations, which describe the reactant, the product, and the five-coordinate intermediate. The model provides a simple picture of reactivity trends in these systems, as well as indicating the way in which a mechanistic spectrum, encompassing both step-wise and concerted pathways, is generated. The model analyzes the effect of modifications of the migrating group, the acceptor group, and the entering ligand. Migratory insertion assisted by either prior oxidation or reduction of the starting metal complex is also considered. The conclusions are supported by experimental and computational data.