Computational Modelling of Selectivity in Cobalt‐Catalyzed Propene Hydroformylation

Abstract

A mechanistic model for the cobalt-catalyzed hydroformylation of propene, based on density functional theory and coupled cluster electronic structure calculations and transition state theory, is proposed to explain the experimentally observed reactivity and selectivity. The electronic structure calculations provide very accurate energies, which are used with transition state theory to compute rate constants; the kinetics of the network of coupled reactions are then modelled numerically for this organometallic reaction. The model accounts well for the dependence of rate on the concentrations of catalysts and reagents, and also on the temperature, and the agreement with experiment is improved still further upon making small adjustments to the ab initio calculated free energy values. The calculations provide detailed kinetic insight into the mechanism of hydroformylation and the role of various elementary steps in defining reactivity and selectivity.

Suzuki–Miyaura coupling revisited: an integrated computational study

“…1 For the -computationally relatively tractable -case of cobalt-catalyzed hydroformylation, we have even been able to predict the rate of catalytic turnover with almost quantitative accuracy. 2 To do this, we have predicted Gibbs energies for all relevant intermediates and TSs, and then predicted the kinetic behaviour of the resulting network of reaction steps. In this paper, we wish to start to carry out a similar process for a much more challenging reaction, namely, one of the most important cases of homogeneous organometallic catalysis, Suzuki-Miyaura coupling of aryl halides and boronic acids.…”

“…Compared to our previous work on oxidative addition to Pd(0), 1 this study will require that we consider many more possible intermediates and reaction steps. Compared to our previous work on hydroformylation, 2 we will need to deal with the complexity of a reaction taking place in multiple phases and involving many charged species (ions or ion pairs). We have found recently 36 that obtaining accurate calculated Gibbs energies for such polar species remains very challenging, with maximum errors on Gibbs energies remaining of the order of 5 kcal mol −1 even when using highly accurate quantum-chemical methods.…”

Propene Hydroformylation Reaction Catalyzed by HRh(CO)(BISBI): A Thermodynamic and Kinetic Analysis of the Full Catalytic Cycle

“…Thus, it is possible to elaborate on an explicit microkinetic model electronic structure calculations provide the rate constants, and the experiment provides the concentration data of reactants and catalysts. [ 64,67,68 ]…”

“…Beforehand, it is important to mention that the expression of Equation (3) is quite similar to the one proposed by Harvey and co‐workers in a computational study involving the hydroformylation reaction promoted by the original cobalt catalyst. [ 64,67 ] The main difference between our models is that in our case, we did not consider the possibility of the alkene hydrogenation reaction, once this parallel reaction is minimized in hydroformylation catalysis promoted by rhodium complexes. Our model also is very similar to the one proposed by van Leeuwen et al [ 18 ] from steady‐state consideration in hydroformylation reaction catalyzed by Rh‐diphosphine catalysts.…”

Computational mechanistic study in organometallic catalysis: Why prediction is still a challenge

“…As noted above, studies of the catalyst activation process and analysis of spent catalytic reactions can also provide important information about entry and exit from the catalytic cycle, informing catalyst design 45,56,57 , and enable the BOX 2: Formalizing computational data analysis with the energetic span approach (Reprinted with permission from Ref. 50) For many catalytic cycles, the overall kinetic information requires consideration of more than one reaction step or transition state, especially when assessment in terms of turnover frequency (TOF) determines the efficiency of a catalytic cycle.…”