Insertion reaction of propene into Rh?H bond in HRh(CO)(PH3)2(C3H6) compound: A density functional study

Rocha, Willian R.; Almeida, Wagner B. De

doi:10.1002/(sici)1097-461x(2000)78:1<42::aid-qua6>3.0.co;2-f

Cited by 32 publications

(32 citation statements)

References 33 publications

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“…First of all, barriers of the olefin association 2 → 3 are assumed to be negligible, too (see Section 3.4.2). Energetically favoured isomers of the remaining transition states 3,4 , 5,6 , 6,7 and 7,2 were selected in agreement with former calculations (see Supporting Information) 5. 17a In most cases their dynamic relaxations towards starting materials/products started within the first 0.1 ps and gave identical isomers for systems b , c and d after a maximum simulation time of 0.6 ps.…”

Section: Resultsmentioning

confidence: 92%

Computational Approaches to Activity in Rhodium‐Catalysed Hydroformylation

Gleich

Hutter

2004

Chemistry A European J

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In this theoretical study on rhodium-catalysed hydroformylation we examine an unmodified hydridorhodium(I) carbonyl system a together with three variants modified by the model phosphane ligands PF3 (system b), PH3 (system c) and PMe3 (system d), which show increasing basicity on the Tolman chi parameter scale. The olefinic substrate for all systems is ethene. Based on the dissociative hydroformylation mechanism, static and dynamic quantum-mechanical approaches are made for preequilibria and the whole catalytic cycle. Agreement with experimental results was achieved with regard to the predominance of phosphane monocoordination in systems b-d, different sensitivity of unmodified and modified systems towards hydrogen pressure and the early location of the rate-determining step. Neither the catalytic cycle as a whole nor olefin insertion as an important selectivity-determining step gives a clear picture of activity differences among a-d. However, the crucial first catalytic step, association of ethene to the active species [HRhL3] (L=CO, PR3), may play the key role in the experimentally observed higher activity of a and systems with less basic phosphane ligands modelled by b.

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Section: Resultsmentioning

confidence: 92%

Computational Approaches to Activity in Rhodium‐Catalysed Hydroformylation

Gleich

Hutter

2004

Chemistry A European J

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“…100 The diequatorial olen adduct was considered as initial compound. The formation of four-coordinate alkyl complexes Rh(PH 3 ) 2 (CO)(propyl) was found to be reversible.…”

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confidence: 99%

Computational aspects of hydroformylation

Kégl

2015

RSC Adv.

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The influence of transition metal complexes as catalysts upon the activity and selectivity of hydroformylation reactions has been extensively investigated during the last decades. Nowadays computational chemistry is an indispensable tool for elucidation of reaction mechanisms and for understanding the various aspects which govern the outcome of catalytic reactions. This review attempts to survey the recent literature concerning computational studies on hydroformylation and theoretical coordination chemistry results related to hydroformylation.

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“…homogeneous process catalyzed by transition metal complexes, that is, low valent cobalt or mainly rhodium catalysts [5][6][7], unmodified or modified with phosphine ligands [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Phosphine-modified rhodium catalysts are in general active at high temperature only (T C 100°C), whereas unmodified Rh catalysts work well even at room temperature (rt) or below T & 60°C [23].…”

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confidence: 99%

The fate of branched and linear isomers in the rhodium-catalyzed hydroformylation of 3,4,4-trimethylpent-1-ene

Alagona

Ghio

2012

Theor Chem Acc

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In nonreversible hydroformylations, the computational evaluation of regio-and stereoselectivities from the relative energy barriers of the transition states (TS) for the alkyl-Rh intermediate formation step is possible, provided all low energy conformers are considered. In contrast, in reversible hydroformylations, also the subsequent reaction steps need to be taken into account to shed some light on mechanistic details. Thus, an extensive comparison of branched (B) and linear (L) reaction pathways for the Rh-catalyzed hydroformylation of 3,4,4-trimethylpent-1-ene (a bulky chiral substrate), going from a number of reactant complexes to products, has been carried out to rationalize the experimental result that pointed to reaction reversibility, although the value of the regioselectivity ratio (B:L = 15:85), based on alkyl-Rh TS free energies, computed under the hypothesis of nonreversibility, was in satisfactory agreement with the experimental one (5:95). A density functional theory approach at the B3P86/6-31G* level coupled to effective core potentials for Rh in the LanL2DZ valence basis set has been employed. By comparing the activation free energies involved in the various steps for the different reactant adducts, interestingly a similar behavior along all the linear pathways is found: the alkyl-Rh formation TS presents the highest barrier; thus, the reaction is nonreversible for all the linear isomers that invariably proceed to yield the linear aldehyde. Conversely, the behavior is quite different along the branched pathways. While some branched isomers eventually produce the corresponding aldehydes, two of the others follow distinct competing pathways, because b-hydride elimination occurs (a) to the terminal olefin-Rh complex (the starting material) that reacts again with the original regioselectivity, increasing the linear fraction, when the CO addition and insertion TS are higher than the alkyl-Rh TS and (b) to the internal olefin-Rh complex when the CO addition and insertion TS are higher than the relevant b-hydride elimination TS, but not than the alkyl-Rh TS. The solvent effect on the reversible profile, evaluated either in the supermolecule approach by adding a benzene molecule to the calculations or in the IEF-PCM framework (e = 2.247), does not bring about any substantial change in the profile, leaving unaltered the conclusions reached.

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Insertion reaction of propene into Rh?H bond in HRh(CO)(PH3)2(C3H6) compound: A density functional study

Cited by 32 publications

References 33 publications

Computational Approaches to Activity in Rhodium‐Catalysed Hydroformylation

Computational Approaches to Activity in Rhodium‐Catalysed Hydroformylation

Computational aspects of hydroformylation

The fate of branched and linear isomers in the rhodium-catalyzed hydroformylation of 3,4,4-trimethylpent-1-ene

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