Steric measurement of substituted cyclopentadiene ligands and the synthesis and proton NMR spectral analysis of [(.eta.5-C5H4R)Fe(CO)(L)I] complexes with variable R

Coville, Neil J.; Loonat, Mohammed S.; White, David P.; Carlton, Laurence

doi:10.1021/om00039a013

Cited by 35 publications

(19 citation statements)

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“…After isolation, the obtained products have been confirmed by spectroscopic studies to be RCpM(CO)[P(OR 0 ) 3 ]I. The spectroscopic data (see Supplementary materials) obtained via the solvent-free conditions are in agreement with the characterization of the same products obtained earlier by solvent procedures [9,11,17,18]. The solvent-free reactions in the presence of Me 3 NO Á 2H 2 O are much faster than reactions carried out in the presence of solvent, e.g.…”

Section: ]Isupporting

confidence: 80%

“…For example, trialkylphosphite ligands P(OR) 3 (R = CH 3 , C 2 H 5 ) have been shown to react with R 0 CpM(CO) 2 X complexes in benzene and toluene as solvents to produce the compounds R 0 CpM(CO)[P(OR) 3 ]X (where R 0 = H, Me, COOMe, etc. ; M = Fe, Ru and X = Cl, Br, I) in high yields, indicating that the reaction is quite facile [7][8][9][10]. The solvent-free reactions have also been performed in the presence of a catalyst, [CpFe(CO) 2 ] 2 .…”

Section: Introductionmentioning

confidence: 99%

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Substitution reactions of Fe and Ru complexes with liquid phosphite ligands in the absence of solvents

Munyaneza

Bala

Coville

2008

Inorganic Chemistry Communications

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Section: ]Isupporting

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Substitution reactions of Fe and Ru complexes with liquid phosphite ligands in the absence of solvents

Munyaneza

Bala

Coville

2008

Inorganic Chemistry Communications

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“…36 Inspired by the TCA definition for dissymetrically-substituted phosphines, we adapted the formalism to substituted Cp X ligands (Figure 4, A). 37 Accordingly, angles α i between the vector defined by the Rh-Cp(centroid) axis and the vectors tangential to the outer most atomic sphere of each substituent R i are measured in DFT-optimized structures (see Supporting Information). Assuming that free rotation of the Cp X ring around the Rh-Cp(centroid) axis takes place in solution, each substituent R i occupies one of the five ring positions only 20% of the time.…”

Section: Resultsmentioning

confidence: 99%

“…34,35,48 Recently, stepwise linear regression algorithms found widespread utility in handling the typically large number of parameters involved in multivariate free energy relationships. 21,36,37 …”

Section: Resultsmentioning

confidence: 99%

Correlating Reactivity and Selectivity to Cyclopentadienyl Ligand Properties in Rh(III)-Catalyzed C–H Activation Reactions: An Experimental and Computational Study

et al. 2017

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CpXRh(III)-catalyzed C-H functionalization reactions are a proven method for the efficient assembly of small molecules. However, rationalization of the effects of cyclopentadienyl (CpX) ligand structure on reaction rate and selectivity has been viewed as a black box, and a truly systematic study is lacking. Consequently, predicting the outcomes of these reactions is challenging because subtle variations in ligand structure can cause notable changes in reaction behavior. A predictive tool is, nonetheless, of considerable value to the community as it would greatly accelerate reaction development. Designing a data set in which the steric and electronic properties of the CpXRh(III) catalysts were systematically varied allowed us to apply multivariate linear regression algorithms to establish correlations between these catalyst-based descriptors and the regio-, diastereoselectivity, and rate of model reactions. This, in turn, led to the development of quantitative predictive models that describe catalyst performance. Our newly-described cone angles and Sterimol parameters for CpX ligands served as highly correlative steric descriptors in the regression models. Through rational design of training and validation sets, key diastereoselectivity outliers were identified. Computations reveal the origins of the outstanding stereoinduction displayed by these outliers. The results are consistent with partial η5−η3 ligand slippage that occurs in the transition state of the selectivity-determining step. In addition to the instructive value of our study, we believe that the insights gained are transposable to other Group 9 transition metals and pave the way toward rational design of C-H functionalization catalysts.

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“…This method was criticized because the obtained values may not reflect the properties of the ligand, particularly when the substituent groups differ greatly [5]. It seems that few geometric tools are available to measure steric effects in organometallic chemistry, and that could explain why ligand cone angles were much used in this field [6][7][8][9], Recently, Bilbrey et al [10][11][12] proposed an analytic solution to the ligand cone angle calculation.…”

Section: Introductionmentioning

confidence: 99%

Analytical algorithms for ligand cone angles calculations. Application to triphenylphosphine palladium complexes

Petitjean

2015

Comptes Rendus. Chimie

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Mots cle´s : Angle conique de Tolman Angle conique de ligand Cône minimal englobant Meilleur cône moyen d-dimensionnel Moindre carré s Indice de conicité A B S T R A C TWe defined the smallest enclosing cone angle as the Tolman cone angle for null atomic spheres radii. Then we provide a simple analytical algorithm to compute the smallest enclosing cone at fixed apex, which works in the case of unsymmetrical ligand. We applied it to compute ligand cones for a family of triphenylphosphine palladium complexes, and we showed that both the angle of the cone and its resulting solid angle strongly correlate with the Tolman cone angle, thus suggesting that there is no more need for atomic radii. We also defined the best cone of fixed apex fitting a population of unit vectors. We proposed a simple analytical algorithm to compute it, which is proved to work in any ddimensional Euclidean space. We defined the conicity index k to evaluate quantitavely the pertinence of the best fitting cone. We used this best fit cone to define a mean ligand cone, and thus a mean cone angle and a mean cone axis. We applied it to our family of triphenylphosphine palladium complexes and we observed that the axis of the individual cones deviated from the mean cone axis by at most 13.28. The observed conicity index was small k ¼ 0:0177 ð Þ, indicating a very good fit for the whole family of complexes. ß 2015 Acadé mie des sciences. Published by Elsevier Masson SAS. All rights reserved. R É S U M ÉNous dé finissons l'angle du plus petit cô ne englobant comme é tant l'angle conique de Tolman à rayons atomiques nuls. Puis, nous fournissons un algorithme analytique simple de calcul du plus petit cô ne englobant à apex fixé , qui fonctionne dans le cas des ligands non symé triques. Nous l'appliquons aux cônes de ligands pour une famille de complexes palladium triphenylphosphine et nous montrons qu'à la fois l'angle du cô ne et l'angle solide qui en ré sulte sont fortement corré lé s avec l'angle conique de Tolman, suggé rant ainsi qu'il n'y a plus besoin des rayons atomiques. Nous dé finissons aussi le meilleur cône moyen d'apex fixé pour une population de vecteurs unitaires. Nous proposons un algorithme analytique simple pour le calculer, que nous prouvons être valide dans tout espace euclidien d-dimensionnel. Nous dé finissons l'indice de conicité k pour é valuer quantitativement la pertinence du meilleur cône. Nous utilisons ce meilleur cô ne pour dé finir un cô ne moyen de ligand, et donc un angle moyen de cône et un axe moyen de cô ne. Nous l'appliquons à notre famille de complexes palladium triphenylphosphine et nous

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Steric measurement of substituted cyclopentadiene ligands and the synthesis and proton NMR spectral analysis of [(.eta.5-C5H4R)Fe(CO)(L)I] complexes with variable R

Cited by 35 publications

References 3 publications

Substitution reactions of Fe and Ru complexes with liquid phosphite ligands in the absence of solvents

Substitution reactions of Fe and Ru complexes with liquid phosphite ligands in the absence of solvents

Correlating Reactivity and Selectivity to Cyclopentadienyl Ligand Properties in Rh(III)-Catalyzed C–H Activation Reactions: An Experimental and Computational Study

Analytical algorithms for ligand cone angles calculations. Application to triphenylphosphine palladium complexes

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