Arene ruthenium iminophosphonamide complexes : synthesis, reactivity and application in transfer hydrogenation of ketones / Iana Sinopalnikova  

Public ISBD Titre : Arene ruthenium iminophosphonamide complexes : synthesis, reactivity and application in transfer hydrogenation of ketones Type de document : texte imprimé Auteurs : Iana Sinopalnikova, Auteur ; Rinaldo Poli, Directeur de thèse ; Alexander Kalsin, Directeur de thèse Langues : Anglais (eng) Tags : RUTHENIUM COMPLEXES  ZWITTERIOINIC LIGANDS  CHLORIDE DISSOCIATION  CARBONYLATION  TRANSFER HYDROGENATION  ACTIVATION MECHANISM Résumé : "Novel half-sandwich 18? and 16? arene ruthenium iminophosphonamide (NPN) complexes [(?6-Arene)RuCl{R2P(NR')2}] (3a-c,e,f), [(?6-C6Me6)RuCl{Ph2P(N-Me)(N-p-Tol)}] (3d) and [(?6-arene)Ru{R2P(NR')2}]+(X-) (4a-c,f) (a, R = Ph, R' = p-Tol; b, R = Et, R' = p-Tol; c, R = Ph, R' = Me; e, R = Ph, R' = p-C6H4COOEt; f, R = Ph, R' = p-Tol. X = BF4, PF6. Arene = C6Me6, p-Cymene) were synthesized and fully characterized. The thermodynamics of chloride dissociation from the 18? NPN complexes has been assessed in both polar and apolar solvents, using variable-temperature UV-visible, NMR and 2D EXSY 1H NMR methods, highlighting the NPN ligand influence on the equilibrium parameters. The dissociation enthalpy ?Hd decreases upon increasing the electron-donating ability of the N-,P- substituents (3e > 3a,f > 3b > 3d > 3c) and the solvent polarity, resulting in the exothermic spontaneous dissociation of 3c in polar solvents. The coordination of neutral ligands (MeCN, pyridine, CO) to the corresponding 16? complexes 4a,c,f is reversible; the stability of the adducts depends on the ?-accepting ability of ligand. Carbonylation of 4a and 4f results rare examples of cationic arene ruthenium carbonyl complexes (5a, 5f), while the monocarbonyl adduct derived from 4c reacts further with a second CO molecule, rapidly converting to the carbonyl-carbamoyl complex 5c', where one CO molecule is inserted into the Ru-N bond. The new carbonyl complexes 5a,f and 5c' were isolated and structurally characterized. For the first time, it has been shown that ruthenium NPN complexes are active catalysts for the transfer hydrogenation of ketones. The catalytic activity increases with the introduction of the p-cymene arene ligand and more electron-donating N substituents. The complexes containing NPN ligands with N-Aryl substitution are activated by a strong base. Model reactions and kinetic studies, backed up by DFT calculations, have established that the key intermediate is a hydride complex. The complexes with N-Me substituted are activated without base, for them we propose cationic complex to be an active intermediate." Document : Thèse de Doctorat Etablissement_delivrance : Université deToulouse 3 Date_soutenance : 21/06/2019 Ecole_doctorale : Sciences de la Matière (SdM) (Toulouse) Domaine : Chimie organométallique et de coordination En ligne : https://theses.hal.science/tel-02880098 Arene ruthenium iminophosphonamide complexes : synthesis, reactivity and application in transfer hydrogenation of ketones [texte imprimé] / Iana Sinopalnikova, Auteur ; Rinaldo Poli, Directeur de thèse ; Alexander Kalsin, Directeur de thèse . - [s.d.]. Langues : Anglais (eng) Tags : RUTHENIUM COMPLEXES  ZWITTERIOINIC LIGANDS  CHLORIDE DISSOCIATION  CARBONYLATION  TRANSFER HYDROGENATION  ACTIVATION MECHANISM Résumé : "Novel half-sandwich 18? and 16? arene ruthenium iminophosphonamide (NPN) complexes [(?6-Arene)RuCl{R2P(NR')2}] (3a-c,e,f), [(?6-C6Me6)RuCl{Ph2P(N-Me)(N-p-Tol)}] (3d) and [(?6-arene)Ru{R2P(NR')2}]+(X-) (4a-c,f) (a, R = Ph, R' = p-Tol; b, R = Et, R' = p-Tol; c, R = Ph, R' = Me; e, R = Ph, R' = p-C6H4COOEt; f, R = Ph, R' = p-Tol. X = BF4, PF6. Arene = C6Me6, p-Cymene) were synthesized and fully characterized. The thermodynamics of chloride dissociation from the 18? NPN complexes has been assessed in both polar and apolar solvents, using variable-temperature UV-visible, NMR and 2D EXSY 1H NMR methods, highlighting the NPN ligand influence on the equilibrium parameters. The dissociation enthalpy ?Hd decreases upon increasing the electron-donating ability of the N-,P- substituents (3e > 3a,f > 3b > 3d > 3c) and the solvent polarity, resulting in the exothermic spontaneous dissociation of 3c in polar solvents. The coordination of neutral ligands (MeCN, pyridine, CO) to the corresponding 16? complexes 4a,c,f is reversible; the stability of the adducts depends on the ?-accepting ability of ligand. Carbonylation of 4a and 4f results rare examples of cationic arene ruthenium carbonyl complexes (5a, 5f), while the monocarbonyl adduct derived from 4c reacts further with a second CO molecule, rapidly converting to the carbonyl-carbamoyl complex 5c', where one CO molecule is inserted into the Ru-N bond. The new carbonyl complexes 5a,f and 5c' were isolated and structurally characterized. For the first time, it has been shown that ruthenium NPN complexes are active catalysts for the transfer hydrogenation of ketones. The catalytic activity increases with the introduction of the p-cymene arene ligand and more electron-donating N substituents. The complexes containing NPN ligands with N-Aryl substitution are activated by a strong base. Model reactions and kinetic studies, backed up by DFT calculations, have established that the key intermediate is a hydride complex. The complexes with N-Me substituted are activated without base, for them we propose cationic complex to be an active intermediate." Document : Thèse de Doctorat Etablissement_delivrance : Université deToulouse 3 Date_soutenance : 21/06/2019 Ecole_doctorale : Sciences de la Matière (SdM) (Toulouse) Domaine : Chimie organométallique et de coordination En ligne : https://theses.hal.science/tel-02880098

From homogeneous to heterogeneous catalysis for solvent-free olefin epoxidation using molybdenum pre-catalysts / Weili Wang  

Public ISBD Titre : From homogeneous to heterogeneous catalysis for solvent-free olefin epoxidation using molybdenum pre-catalysts Type de document : texte imprimé Auteurs : Weili Wang, Auteur ; Rinaldo Poli, Directeur de thèse ; Dominique Agustin, Directeur de thèse Langues : Français (fre) Tags : HOMOGENEOUS CATALYSIS  HETEROGENEOUS CATALYSIS  EPOXIDATION WITHOUT ORGANIC SOLVENT MOLYBDENUM  GREEN CHEMISTRY  GRAFTING ON SUPPORT  LIMONENE  CYCLOOCTENE Résumé : "The work of this PhD thesis deals with the study of molybdenum complexes of general formula [MoO2L]n (L being a tridentate Schiff base ligand with an ONO or ONS coordination sphere around the molybdenum) as catalysts for the organic solvent-free epoxidation of olefins. Within the spirit of Green Chemistry, the work has focused on four of the twelve Green Chemistry principles: the use of catalysis rather than stoichiometric transformations, the use of organic solvent-free procedures rather than operating in solution of organic solvents, the use of renewable substrates and the grafting of catalysts for their recovery. The first part of the manuscript presents a concise state of the art on the chemistry of molybdenum complexes with ligands similar to those used within the thesis. Specific aspects such as the effect of ligand substituents and the different activities – mainly catalytic – observed in organic media are reviewed. A section of this chapter is dedicated to the different strategies employed for the grafting of molybdenum complexes to solid supports as well as to the use of the resulting supported complexes in heterogenized homogeneous catalysis. The next chapter details the synthesis and characterization of all the molecular complexes used as catalysts. This chapter shows the different substitutions operated on the ligands, i.e. changing the ONO coordination sphere to ONS and adding different substituents on the ligands, i.e. OH free functions or additional donor (diethylamino) and/or withdrawing (nitro) substituents at different positions on the tridentate ligand in order to modify the catalytic activity. Six of the synthesized complexes could be characterized by X-ray crystallography. The third chapter reports the results obtained for the catalyzed organic solvent-free epoxidation of cyclooctene as a model substrate using all the molybdenum complexes presented in the previous chapter. It is shown that the nature of the coordination sphere around the molybdenum (ONO vs ONS) is in favour of the latter in terms of catalytic activity towards the formation of the desired epoxide. The catalyzed reactions with complexes containing an OH substituent at different positions on the aromatic ring have shown more significant effects in the case of the ONO coordination sphere than in the corresponding ONS case. The epoxidation performed in the presence of a dimethylamino and/or a nitro substituent on the ONO ligand revealed that the catalytic activity is enhanced by the electron withdrawing group. The catalytic investigations were pursued by the epoxidation of cyclohexene and of one natural substrate, limonene. This study has shown that limonene oxides and/or limonene diols are generated, depending on the nature of the catalyst. The ONS complexes are very reactive and quickly lead to the limonene diols. The effect of different parameters has been studied with particular attention to the reaction temperature. Finally, one stable molybdenum complex with an ONO coordination sphere has been grafted onto a commercial Merrifield resin. Different grafting strategies are presented. The isolated objects have been tested as catalysts under organic solvent-free conditions for the epoxidation of cyclooctene. The catalytic results are promising in terms of activity and the recovery/recycling tests have shown that the catalysts could be used three times without significant decrease of conversion and selectivity, but some metal leaching was observed." Document : Thèse de Doctorat Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 17/09/2015 Ecole_doctorale : Sciences de la matière (SdM) Domaine : Chimie organométallique de coordination En ligne : http://thesesups.ups-tlse.fr/2917/ From homogeneous to heterogeneous catalysis for solvent-free olefin epoxidation using molybdenum pre-catalysts [texte imprimé] / Weili Wang, Auteur ; Rinaldo Poli, Directeur de thèse ; Dominique Agustin, Directeur de thèse . - [s.d.]. Langues : Français (fre) Tags : HOMOGENEOUS CATALYSIS  HETEROGENEOUS CATALYSIS  EPOXIDATION WITHOUT ORGANIC SOLVENT MOLYBDENUM  GREEN CHEMISTRY  GRAFTING ON SUPPORT  LIMONENE  CYCLOOCTENE Résumé : "The work of this PhD thesis deals with the study of molybdenum complexes of general formula [MoO2L]n (L being a tridentate Schiff base ligand with an ONO or ONS coordination sphere around the molybdenum) as catalysts for the organic solvent-free epoxidation of olefins. Within the spirit of Green Chemistry, the work has focused on four of the twelve Green Chemistry principles: the use of catalysis rather than stoichiometric transformations, the use of organic solvent-free procedures rather than operating in solution of organic solvents, the use of renewable substrates and the grafting of catalysts for their recovery. The first part of the manuscript presents a concise state of the art on the chemistry of molybdenum complexes with ligands similar to those used within the thesis. Specific aspects such as the effect of ligand substituents and the different activities – mainly catalytic – observed in organic media are reviewed. A section of this chapter is dedicated to the different strategies employed for the grafting of molybdenum complexes to solid supports as well as to the use of the resulting supported complexes in heterogenized homogeneous catalysis. The next chapter details the synthesis and characterization of all the molecular complexes used as catalysts. This chapter shows the different substitutions operated on the ligands, i.e. changing the ONO coordination sphere to ONS and adding different substituents on the ligands, i.e. OH free functions or additional donor (diethylamino) and/or withdrawing (nitro) substituents at different positions on the tridentate ligand in order to modify the catalytic activity. Six of the synthesized complexes could be characterized by X-ray crystallography. The third chapter reports the results obtained for the catalyzed organic solvent-free epoxidation of cyclooctene as a model substrate using all the molybdenum complexes presented in the previous chapter. It is shown that the nature of the coordination sphere around the molybdenum (ONO vs ONS) is in favour of the latter in terms of catalytic activity towards the formation of the desired epoxide. The catalyzed reactions with complexes containing an OH substituent at different positions on the aromatic ring have shown more significant effects in the case of the ONO coordination sphere than in the corresponding ONS case. The epoxidation performed in the presence of a dimethylamino and/or a nitro substituent on the ONO ligand revealed that the catalytic activity is enhanced by the electron withdrawing group. The catalytic investigations were pursued by the epoxidation of cyclohexene and of one natural substrate, limonene. This study has shown that limonene oxides and/or limonene diols are generated, depending on the nature of the catalyst. The ONS complexes are very reactive and quickly lead to the limonene diols. The effect of different parameters has been studied with particular attention to the reaction temperature. Finally, one stable molybdenum complex with an ONO coordination sphere has been grafted onto a commercial Merrifield resin. Different grafting strategies are presented. The isolated objects have been tested as catalysts under organic solvent-free conditions for the epoxidation of cyclooctene. The catalytic results are promising in terms of activity and the recovery/recycling tests have shown that the catalysts could be used three times without significant decrease of conversion and selectivity, but some metal leaching was observed." Document : Thèse de Doctorat Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 17/09/2015 Ecole_doctorale : Sciences de la matière (SdM) Domaine : Chimie organométallique de coordination En ligne : http://thesesups.ups-tlse.fr/2917/

New approach to aqueous biphasic catalysis through catalyst confinement in nanoscopic core-shell polymers / Si Chen  

Public ISBD Titre : New approach to aqueous biphasic catalysis through catalyst confinement in nanoscopic core-shell polymers Type de document : texte imprimé Auteurs : Si Chen, Auteur ; Rinaldo Poli, Directeur de thèse ; Manoury, Eric, Directeur de thèse Langues : Anglais (eng) Tags : CORE-SHELL POLYMERS  CATALYTIC NANOREACTORS  MACROMOLECULAR  RAFT - BIPHASIC CATALYSIS  EMULSION POLYMERIZATION  HYDROFORMYLATION PISA Résumé : "The catalytic processes are at the heart of chemical industry. Modern chemical industry, under pressure of stricter regulations and societal concern, is faced with the need to improve efficiency and cleaner production processes and catalysis is one the major keys to green chemical technology. Catalysts recovery is necessary from an economic and environmental point of view when it makes use of expensive and / or toxic metals. The aim of this thesis is based on an innovative approach related to micellar catalyst but in which the catalyst is covalent linked to the hydrophobic core of well-defined unimolecular, core-cross-linked micelles. The synthetic protocol is based on a convergent method via RAFT-mediated one-pot aqueous emulsion polymerization. The efficiency of these unimolecular micelles as catalytic nanoreactors has been shown using the industrially relevant hydroformylation of 1-octene, in order to provide a proof of principle, as a test reaction yielding turnover frequencies and l/b ratio comparable to those of related homogeneous systems. However, the catalyst phase could be easily separated from the organic product phase and recycled. A remarkable protecting effect of the active catalyst by the polymer scaffold has also been demonstrated. The absence of the coagulation at the end of reaction is evidence that these new objects function as micelles while eliminating the disadvantages of micellar catalysis such as the formation of stable emulsion." Document : Thèse de Doctorat Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 28/09/2015 Ecole_doctorale : Sciences de la matière (SdM) Domaine : Chimie Moléculaire, industrielle, polymères En ligne : http://thesesups.ups-tlse.fr/2906/ New approach to aqueous biphasic catalysis through catalyst confinement in nanoscopic core-shell polymers [texte imprimé] / Si Chen, Auteur ; Rinaldo Poli, Directeur de thèse ; Manoury, Eric, Directeur de thèse . - [s.d.]. Langues : Anglais (eng) Tags : CORE-SHELL POLYMERS  CATALYTIC NANOREACTORS  MACROMOLECULAR  RAFT - BIPHASIC CATALYSIS  EMULSION POLYMERIZATION  HYDROFORMYLATION PISA Résumé : "The catalytic processes are at the heart of chemical industry. Modern chemical industry, under pressure of stricter regulations and societal concern, is faced with the need to improve efficiency and cleaner production processes and catalysis is one the major keys to green chemical technology. Catalysts recovery is necessary from an economic and environmental point of view when it makes use of expensive and / or toxic metals. The aim of this thesis is based on an innovative approach related to micellar catalyst but in which the catalyst is covalent linked to the hydrophobic core of well-defined unimolecular, core-cross-linked micelles. The synthetic protocol is based on a convergent method via RAFT-mediated one-pot aqueous emulsion polymerization. The efficiency of these unimolecular micelles as catalytic nanoreactors has been shown using the industrially relevant hydroformylation of 1-octene, in order to provide a proof of principle, as a test reaction yielding turnover frequencies and l/b ratio comparable to those of related homogeneous systems. However, the catalyst phase could be easily separated from the organic product phase and recycled. A remarkable protecting effect of the active catalyst by the polymer scaffold has also been demonstrated. The absence of the coagulation at the end of reaction is evidence that these new objects function as micelles while eliminating the disadvantages of micellar catalysis such as the formation of stable emulsion." Document : Thèse de Doctorat Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 28/09/2015 Ecole_doctorale : Sciences de la matière (SdM) Domaine : Chimie Moléculaire, industrielle, polymères En ligne : http://thesesups.ups-tlse.fr/2906/

New chiral, tridentate, phosphine group containing ferrocenyl ligands for asymmetric catalysis with non-noble metals / Uchchhal Bandyopadhyay  

Public ISBD Titre : New chiral, tridentate, phosphine group containing ferrocenyl ligands for asymmetric catalysis with non-noble metals Type de document : texte imprimé Auteurs : Uchchhal Bandyopadhyay, Auteur ; Rinaldo Poli, Directeur de thèse ; Manoury, Eric, Directeur de thèse Langues : Anglais (eng) Tags : CHIRAL  LIGANDS BIOCHEMISTRY  ASYMMETRIC CATALYSIS  RACEMIC  TRIDENTATE: LIGANDS  SYNTHESIS  FERROCENE  PHOSPHINE  CHARACTERIZATION  CRYSTAL STRUCTURE  CHIRALITY CHIRAUX  LIGANDS BIOCHIMIE  CATALYSE ASYMÉTRIQUE  RACÉMIQUE  TRIDENTES : LIGANDS  SYNTHESE  FERROCENIQUE  CARACTERISATION  STRUCTURE CRISTALLINE  CHIRALITE CHIRAUX  TRIDENTÉS : LIGANDS  SYNTHÈSE  FÉRROCENIQUE  CARACTÉRISATION  CHIRALITE Résumé : "Phosphine-containing planar chiral ferrocene-based ligands and their metal complexes have set a benchmark to carry out asymmetric catalytic transformations during the last few decades. Nevertheless, most of the competent metal complexes till date are found to be noble or late transition metal (Rh, Ru, Ir, Pd etc.) complexes. To circumvent the limited availability of this kind of fast depleting metals, non-noble or early transition metals (Mn, Fe, Co) are gaining severe attention in all kind of fields of catalysis. Recent work on non-noble metal catalysis has shown the potential of tridentate ligands (achiral and chiral) in a number of transformations, including the asymmetric ones. Based on these considerations, various Phosphine-containing tridentate, planar chiral ligands based on ferrocene scaffold (e.g.- PNN, PNP, PSP, PSN etc.) were designed. Various organic and organometallic reactions were thoroughly explored, during the course of multistep ligand synthesis processes. A large number of new organic and ferrocenyl compounds were isolated by chromatographic separations and crystallizations; and also, fully characterized (multinuclear NMR, HRMS, XRD diffraction analysis on monocrystals, etc)." Document : Thèse de Doctora Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 22/07/2021 Ecole_doctorale : Sciences de la Matière (SdM) (Toulouse) Domaine : Chimie organométallique et de coordination En ligne : https://theses.fr/2021TOU30072 New chiral, tridentate, phosphine group containing ferrocenyl ligands for asymmetric catalysis with non-noble metals [texte imprimé] / Uchchhal Bandyopadhyay, Auteur ; Rinaldo Poli, Directeur de thèse ; Manoury, Eric, Directeur de thèse . - [s.d.]. Langues : Anglais (eng) Tags : CHIRAL  LIGANDS BIOCHEMISTRY  ASYMMETRIC CATALYSIS  RACEMIC  TRIDENTATE: LIGANDS  SYNTHESIS  FERROCENE  PHOSPHINE  CHARACTERIZATION  CRYSTAL STRUCTURE  CHIRALITY CHIRAUX  LIGANDS BIOCHIMIE  CATALYSE ASYMÉTRIQUE  RACÉMIQUE  TRIDENTES : LIGANDS  SYNTHESE  FERROCENIQUE  CARACTERISATION  STRUCTURE CRISTALLINE  CHIRALITE CHIRAUX  TRIDENTÉS : LIGANDS  SYNTHÈSE  FÉRROCENIQUE  CARACTÉRISATION  CHIRALITE Résumé : "Phosphine-containing planar chiral ferrocene-based ligands and their metal complexes have set a benchmark to carry out asymmetric catalytic transformations during the last few decades. Nevertheless, most of the competent metal complexes till date are found to be noble or late transition metal (Rh, Ru, Ir, Pd etc.) complexes. To circumvent the limited availability of this kind of fast depleting metals, non-noble or early transition metals (Mn, Fe, Co) are gaining severe attention in all kind of fields of catalysis. Recent work on non-noble metal catalysis has shown the potential of tridentate ligands (achiral and chiral) in a number of transformations, including the asymmetric ones. Based on these considerations, various Phosphine-containing tridentate, planar chiral ligands based on ferrocene scaffold (e.g.- PNN, PNP, PSP, PSN etc.) were designed. Various organic and organometallic reactions were thoroughly explored, during the course of multistep ligand synthesis processes. A large number of new organic and ferrocenyl compounds were isolated by chromatographic separations and crystallizations; and also, fully characterized (multinuclear NMR, HRMS, XRD diffraction analysis on monocrystals, etc)." Document : Thèse de Doctora Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 22/07/2021 Ecole_doctorale : Sciences de la Matière (SdM) (Toulouse) Domaine : Chimie organométallique et de coordination En ligne : https://theses.fr/2021TOU30072

Polar substrates asymmetric hydrogenation and associated processes : role of the base / Paven Kisten,  

Public ISBD Titre : Polar substrates asymmetric hydrogenation and associated processes : role of the base Titre original : Hydrogénation asymétrique des substrats polaires et processus associés : rôle de la base Type de document : texte imprimé Auteurs : Paven Kisten,, Auteur ; Rinaldo Poli, Auteur ; Simon Duckett, Auteur Langues : Anglais (eng) Tags : ORGANOMETALLICS  LIGANDS  THEORETICAL CALCULATIONS  DFT  NMR ORGANOMÉTALLIQUES  CALCULS THÉORIQUES  RMN Résumé : "New mechanistic views have emerged to account for the activity of systems with non-deprotonatable ligands towards hydrogenation and transfer hydrogenation of polar substrates, which nevertheless need a strong base for activity. In this work, the role of the base in the associated chemistry of [IrCl(COD)(dppe)] is studied. In the presence of an alkoxide with a bêta-hydrogen, two monohydride complexes of the form [IrH(C8H12)(dppe)] result, which interconvert with a Gibbs energy difference of 2.06 ± 0.16 kcal mol-1. This process was followed by DFT calculation, and the difference predicted to be 3.5 kcal mol-1. When no bêta-hydrogen is present, two monohydride complexes form by COD deprotonation, [IrH(1-k-4,5,6-êta3-C8H10)(dppe)]. DFT calculations were used to rationalize this behaviour, and mechanism of reaction. The resulting thermodynamic (-0.5 kcal mol-1) differences were in excellent agreement with the experimental value (-0.51 ± 0.04 kcal mol-1). These model complexes were transformed by heating in the presence of KOtBu (or NaOMe) and isopropanol at 80 °C, to M[IrH4(dppe)] (M = K, Na). Similar IrIII products (M[Ir(H)4(L2)] (L2 = dppf, (S)-BINAP) were selectively generated from [IrCl(COD)(L2)]. Finally, the alkali metal-dependent transfer hydrogenation activity of these complexes was examined and rationalized for benzophenone. The active catalyst, generated in situ from [IrCl(COD)]2 and (P,SR) under H2 in the presence of a strong base (M+iPrO- in isopropanol, M = Li, Na, K), is the solvated M[Ir(H)4(P,SR)] salt (P,SR = CpFe[1,2-C5H3(PPh2)(CH2SR)], with R = iPr, Bz, Ph and Cy). Their activity proved to increase, for all R derivatives, in the order Li < Na < K. On the other hand, the nature of the cation did not effect the ee. The DFT calculations revealed the critical importance of the alkali-metal cation coordination sphere in reproducing the experimental results. The rate-determining barrier corresponds to outer-sphere hydride transfer and enantio-discriminating interactions are rationalized for the cation." "De nouveaux points de vue mécanistes sont apparus pour expliquer l'activité des systèmes avec des ligands non déprotonnables pour l'hydrogénation et l'hydrogénation par transfert de substrats polaires, qui ont néanmoins besoin d'une base forte pour être actifs. Dans ce travail, le rôle de la base dans la chimie associée de [IrCl(COD)(dppe)] est étudié. En présence d'un alcoxyde avec un bêta-hydrogène, deux complexes monohydrides de la forme [IrH(C8H12)(dppe)] résultent, qui s'interconvertissent avec une différence d'énergie de Gibbs de 2.06 ± 0.16 kcal mol-1. Ce processus a été suivi par un calcul DFT, et la différence prédite est de 3,5 kcal mol-1. En l'absence de bêta-hydrogène, deux complexes monohydrides se forment par déprotonation COD, [IrH(1-k-4,5,6-êta3-C8H10)(dppe)]. Des calculs DFT ont été utilisés pour rationaliser ce comportement et le mécanisme de réaction. Les différences thermodynamiques qui en résultent (-0,5 kcal mol-1) sont en excellent accord avec la valeur expérimentale (-0,51 ± 0,04 kcal mol-1). Ces complexes modèles ont été transformés par chauffage en présence de KOtBu (ou NaOMe) et d'isopropanol à 80 °C, en M[IrH4(dppe)] (M = K, Na). Des produits IrIII similaires (M[Ir(H)4(L2)] (L2 = dppf, (S)-BINAP) ont été sélectivement générés à partir de [IrCl(COD)(L2)]. Enfin, l'activité d'hydrogénation par transfert dépendant des métaux alcalins de ces complexes a été examinée et rationalisée pour la benzophénone. Le catalyseur actif, généré in situ à partir de [IrCl(COD)]2 et (P,SR) sous H2 en présence d'une base forte (M+iPrO- dans l'isopropanol, M = Li, Na, K), est le sel solvaté M[Ir(H)4(P,SR)] (P,SR = CpFe[1,2-C5H3(PPh2)(CH2SR)], avec R = iPr, Bz, Ph et Cy). Leur activité s'est avérée augmenter, pour tous les dérivés R, dans l'ordre Li < Na < K. Par ailleurs, la nature du cation n'a pas eu d'effet sur l'ee. Les calculs DFT ont révélé l'importance critique de la sphère de coordination du cation alcalin-métallique dans la reproduction des résultats expérimentaux. La barrière déterminant le taux correspond au transfert d'hydrure de la sphère externe et les interactions énantio-discriminantes sont rationalisées pour le cation." Document : Thèse de Doctorat Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 28/11/2023 Ecole_doctorale : Sciences de la matière (SdM) (Toulouse) Domaine : Chimie Organométallique et de Coordination En ligne : https://theses.hal.science/tel-04573895v1 Polar substrates asymmetric hydrogenation and associated processes : role of the base = Hydrogénation asymétrique des substrats polaires et processus associés : rôle de la base [texte imprimé] / Paven Kisten,, Auteur ; Rinaldo Poli, Auteur ; Simon Duckett, Auteur . - [s.d.]. Langues : Anglais (eng) Tags : ORGANOMETALLICS  LIGANDS  THEORETICAL CALCULATIONS  DFT  NMR ORGANOMÉTALLIQUES  CALCULS THÉORIQUES  RMN Résumé : "New mechanistic views have emerged to account for the activity of systems with non-deprotonatable ligands towards hydrogenation and transfer hydrogenation of polar substrates, which nevertheless need a strong base for activity. In this work, the role of the base in the associated chemistry of [IrCl(COD)(dppe)] is studied. In the presence of an alkoxide with a bêta-hydrogen, two monohydride complexes of the form [IrH(C8H12)(dppe)] result, which interconvert with a Gibbs energy difference of 2.06 ± 0.16 kcal mol-1. This process was followed by DFT calculation, and the difference predicted to be 3.5 kcal mol-1. When no bêta-hydrogen is present, two monohydride complexes form by COD deprotonation, [IrH(1-k-4,5,6-êta3-C8H10)(dppe)]. DFT calculations were used to rationalize this behaviour, and mechanism of reaction. The resulting thermodynamic (-0.5 kcal mol-1) differences were in excellent agreement with the experimental value (-0.51 ± 0.04 kcal mol-1). These model complexes were transformed by heating in the presence of KOtBu (or NaOMe) and isopropanol at 80 °C, to M[IrH4(dppe)] (M = K, Na). Similar IrIII products (M[Ir(H)4(L2)] (L2 = dppf, (S)-BINAP) were selectively generated from [IrCl(COD)(L2)]. Finally, the alkali metal-dependent transfer hydrogenation activity of these complexes was examined and rationalized for benzophenone. The active catalyst, generated in situ from [IrCl(COD)]2 and (P,SR) under H2 in the presence of a strong base (M+iPrO- in isopropanol, M = Li, Na, K), is the solvated M[Ir(H)4(P,SR)] salt (P,SR = CpFe[1,2-C5H3(PPh2)(CH2SR)], with R = iPr, Bz, Ph and Cy). Their activity proved to increase, for all R derivatives, in the order Li < Na < K. On the other hand, the nature of the cation did not effect the ee. The DFT calculations revealed the critical importance of the alkali-metal cation coordination sphere in reproducing the experimental results. The rate-determining barrier corresponds to outer-sphere hydride transfer and enantio-discriminating interactions are rationalized for the cation." "De nouveaux points de vue mécanistes sont apparus pour expliquer l'activité des systèmes avec des ligands non déprotonnables pour l'hydrogénation et l'hydrogénation par transfert de substrats polaires, qui ont néanmoins besoin d'une base forte pour être actifs. Dans ce travail, le rôle de la base dans la chimie associée de [IrCl(COD)(dppe)] est étudié. En présence d'un alcoxyde avec un bêta-hydrogène, deux complexes monohydrides de la forme [IrH(C8H12)(dppe)] résultent, qui s'interconvertissent avec une différence d'énergie de Gibbs de 2.06 ± 0.16 kcal mol-1. Ce processus a été suivi par un calcul DFT, et la différence prédite est de 3,5 kcal mol-1. En l'absence de bêta-hydrogène, deux complexes monohydrides se forment par déprotonation COD, [IrH(1-k-4,5,6-êta3-C8H10)(dppe)]. Des calculs DFT ont été utilisés pour rationaliser ce comportement et le mécanisme de réaction. Les différences thermodynamiques qui en résultent (-0,5 kcal mol-1) sont en excellent accord avec la valeur expérimentale (-0,51 ± 0,04 kcal mol-1). Ces complexes modèles ont été transformés par chauffage en présence de KOtBu (ou NaOMe) et d'isopropanol à 80 °C, en M[IrH4(dppe)] (M = K, Na). Des produits IrIII similaires (M[Ir(H)4(L2)] (L2 = dppf, (S)-BINAP) ont été sélectivement générés à partir de [IrCl(COD)(L2)]. Enfin, l'activité d'hydrogénation par transfert dépendant des métaux alcalins de ces complexes a été examinée et rationalisée pour la benzophénone. Le catalyseur actif, généré in situ à partir de [IrCl(COD)]2 et (P,SR) sous H2 en présence d'une base forte (M+iPrO- dans l'isopropanol, M = Li, Na, K), est le sel solvaté M[Ir(H)4(P,SR)] (P,SR = CpFe[1,2-C5H3(PPh2)(CH2SR)], avec R = iPr, Bz, Ph et Cy). Leur activité s'est avérée augmenter, pour tous les dérivés R, dans l'ordre Li < Na < K. Par ailleurs, la nature du cation n'a pas eu d'effet sur l'ee. Les calculs DFT ont révélé l'importance critique de la sphère de coordination du cation alcalin-métallique dans la reproduction des résultats expérimentaux. La barrière déterminant le taux correspond au transfert d'hydrure de la sphère externe et les interactions énantio-discriminantes sont rationalisées pour le cation." Document : Thèse de Doctorat Etablissement_delivrance : Université Toulouse 3 Date_soutenance : 28/11/2023 Ecole_doctorale : Sciences de la matière (SdM) (Toulouse) Domaine : Chimie Organométallique et de Coordination En ligne : https://theses.hal.science/tel-04573895v1

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