Insertion, migratory comparison

Niu, S., Hall, M. B., 1997, Comparison of Hartree-Fock, Density Functional, Mpller-Plesset Perturbation, Coupled Cluster, and Configuration Interaction Methods for the Migratory Insertion of Nitric Oxide into a Cobalt-Carbon Bond , J. Phys. Chem. A, 101, 1360. 

The effect of solvent polarity on the rate of the individual steps was also deduced from a comparison of the kinetics determined by IR. It was concluded that, comparing MeOH/Mel (80 20 v/v) with CH2Q2/MCI (80 20 v/v), the overall increase in rate of reaction of [Rh(CO)2l2] with Mel to give [Rh(C(0)Me)( CO)I] included contributions due to enhancement of the forward rates of both oxidative addition (ca. 50%) and migratory insertion (ca. 100%). 

Iridium-catalyzed hydrogenations of olefins and ketmies have also been reported. These reactions have not yet been studied computationally at the level of detail of the rhodium- and ruthenium-catalyzed reactions, and comparisons to experiments have been less clear. As a result, only a very general description of the mechanism and rationalization of the stereoselective outcome is available at this time. The results do, however, clearly demonstrates that amidst such mechanistic diversity of the iridium- and the ruthenium-catalyzed reactions, they prefer either the direct transfer after migratory insertion, or the concerted transfer. 

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