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Matthias Tacke - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Cytotoxicity Studies of Silyl-Substituted Titanocene Dichloride Derivatives
Organometallics, 2012Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Helge Müller-bunz, Matthias TackeAbstract:Six new titanocene compounds have been isolated and characterized. These compounds were synthesized from their silyl-substituted fulvene or cyclopentadiene precursors using Super Hydride (LiBEt3H) or n-BuLi, followed by transmetalation with titanium tetrachloride, to yield the corresponding titanocene dichloride derivatives. These complexes are bis-[((phenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3a), bis-[((4-methoxyphenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3b), bis-[((4-N,N-dimethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3c), bis-[((4-N,N-diethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3d), bis-[((1-methyl-5-trimethylsilyl)indol-3-yl)methylCyclopentadienyl] titanium(IV) dichloride (4e), and bis-[((1-methyl-3-diethylaminomethyl-5-trimethylsilyl)indol-2-yl)methylCyclopentadienyl] titanium(IV) dichloride (4f). The two titanocenes 3a and 3b were crystallized and characterized by X-ray crystallography, while ...
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Synthesis and Cytotoxicity Studies of Silyl-Substituted Titanocene Dichloride Derivatives
2012Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Helge Müller-bunz, Matthias TackeAbstract:Six new titanocene compounds have been isolated and characterized. These compounds were synthesized from their silyl-substituted fulvene or cyclopentadiene precursors using Super Hydride (LiBEt3H) or n-BuLi, followed by transmetalation with titanium tetrachloride, to yield the corresponding titanocene dichloride derivatives. These complexes are bis-[((phenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3a), bis-[((4-methoxyphenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3b), bis-[((4-N,N-dimethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3c), bis-[((4-N,N-diethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3d), bis-[((1-methyl-5-trimethylsilyl)indol-3-yl)methylCyclopentadienyl] titanium(IV) dichloride (4e), and bis-[((1-methyl-3-diethylaminomethyl-5-trimethylsilyl)indol-2-yl)methylCyclopentadienyl] titanium(IV) dichloride (4f). The two titanocenes 3a and 3b were crystallized and characterized by X-ray crystallography, while all six titanocenes were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines in order to determine their IC50 values. Titanocenes were found to have IC50 values of 139 (±5), 106 (± 4), 127 (±4), 104 (±9), 90 (±6), and 15 (±2) μM
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synthesis and cytotoxicity studies of achiral azaindole substituted titanocenes
Heteroatom Chemistry, 2011Co-Authors: Luis Miguel Menéndez Méndez, Anthony Deally, Donal F Oshea, Matthias TackeAbstract:From the reaction of 1-methyl-1 H-pyr-rolo[2,3-b]pyridine (1a),1-(methoxymethyl)-1 H-pyrrolo[2,3-b]pyridine (1b), 1-isopropyl-1 H-pyrrolo[2,3-b]pyridine (1c), and 1-(4-methoxybenzyl)-1 H-pyrrolo[2,3-b]pyridine (1d) under Vilsmeier–Haak conditions, the corresponding aldehydes in position 3 (2a–2d) were synthesized. These aldehydes were transformed in the corresponding fulvenes (3a–3d) by the Knoevenagel condensation and treated with Li[BEt3H] to obtain the corresponding lithiated cyclopentadienide intermediates (3′a–3′d). These intermediates were, finally transmetallated to titanium with TiCl4 to yield the 7-azaindol-3-yl-substituted titanocenes bis {[(1-methyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl] Cyclopentadienyl} titanium(IV) dichloride (4a), bis{[(1-methoxymethyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl]Cyclopentadienyl} titanium(IV)dichloride (4b), bis{[(1-Isopropyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl]Cyclopentadienyl} titanium(IV) dichloride (4c), and bis{[(4-methoxybenzyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl]Cyclopentadienyl} titanium(IV) dichloride (4d). All the titanocenes had their cytotoxicity investigated through MTT-based preliminary in vitro testing on the Caki-1 cell lines to determinate their IC50 values. Titanocenes 4a–4c were found to have IC50 values of 120 ± 10, 83 ± 13, and 54 ± 12, µM respectively, whereas 4d showed no cytotoxic activity. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:148–157, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20668
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synthesis and preliminary cytotoxicity studies of achiral pyrrolyl substituted titanocenes
Polyhedron, 2010Co-Authors: Anthony Deally, James Claffey, Megan Hogan, Helge Mullerbunz, Brendan Gleeson, Siddappa A Patil, Donal F Oshea, Matthias TackeAbstract:From the reaction of various 6-indolylfulvenes (1a−f) with Super Hydride (LiBEt3H), followed by transmetalation with titanium tetrachloride (TiCl4), six indolyl-substituted titanocenes, bis[(1-methylindol-2-yl)Cyclopentadienyl]titanium(IV) dichloride (3a), bis[(1-methyl-5-methoxyindol-2-yl)Cyclopentadienyl]titanium(IV) dichloride (3b), a dihydrochloride derivative of bis[(1-methyl-3-dimethylaminomethylindol-2-yl)Cyclopentadienyl]titanium(IV) dichloride (3c), bis[(1-methylindol-3-yl)Cyclopentadienyl]titanium(IV) dichloride (3d), bis[(1-methyl-5-methoxyindol-3-yl)Cyclopentadienyl]titanium(IV) dichloride (3e), and bis[(1-methylmethoxyindol-3-yl)Cyclopentadienyl]titanium(IV) dichloride (3f), were obtained. The six titanocenes 3a−f were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines in order to determine their IC50 values. Titanocenes 3a−f were found to have IC50 values of 47 (±9), 15 (±2), 8.2 (±1.9), 21 (±5), 11 (±1), and 170 (±40) μM, respectively.
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Synthesis and Cytotoxicity Studies of Fluorinated Derivatives of Vanadocene Y
European Journal of Inorganic Chemistry, 2009Co-Authors: Brendan Gleeson, James Claffey, Megan Hogan, Anthony Deally, Helge Müller-bunz, Siddappa A Patil, Luis Miguel Menéndez Méndez, Denise Wallis, Matthias TackeAbstract:From the reaction of 6-(2-fluoro-4-methoxyphenyl)fulvene (1a), 6-(3-fluoro-4-methoxyphenyl)fulvene (1b) and 6-[4-(trifluoromethoxy)phenyl]fulvene (1c) with LiBEt3H, lithiated cyclopentadienide intermediates (2a–c) were synthesised. These intermediates were then transmetallated to vanadium with VCl4 to yield the benzyl-substituted vanadocenes bis[(2-fluoro-4-methoxybenzyl)Cyclopentadienyl]vanadium(IV) dichloride (3a), bis[(3-fluoro-4-methoxybenzyl)Cyclopentadienyl]vanadium(IV) dichloride (3b), and bis[(4-trifluoromethoxybenzyl)Cyclopentadienyl]vanadium(IV) dichloride (3c). The three vanadocenes 3a–c were characterised by single-crystal X-ray diffraction. All three vanadocenes had their cytotoxicity investigated through MTT-based preliminary in-vitro testing on the LLC-PK and Caki-1 cell lines in order to determine their IC50 values. Vanadocenes 3a–c were found to have IC50 values of 6.0 (+/–4), 35 (+/–7) and 13 (+/–3) μM on the LLC-PK cell line and IC50 values of 78 (+/–11), 18 (+/–16) and 2.2 (+/–0.5) μM on the Caki-1 cell line respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Shigetoshi Takahashi - One of the best experts on this subject based on the ideXlab platform.
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diastereoselective oxidative addition of allyl chloride to planar chiral Cyclopentadienyl ruthenium complexes
Organometallics, 2004Co-Authors: Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi TakahashiAbstract:The reaction of planar-chiral Cyclopentadienyl−ruthenium complexes with allyl chloride at room temperature resulted in the diastereoselective formation of π-allyl−ruthenium complexes, in which the chirality at the Ru center depended on the substituent at the 4-position of the Cyclopentadienyl group. Epimerization at the Ru center of π-allyl complexes at 90 °C suggested that the diastereoselectivity was under kinetic control.
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stereoselective ligand exchange reaction of planar chiral Cyclopentadienyl ruthenium complexes thermodynamic control of configuration at a stereogenic metal center
Dalton Transactions, 2004Co-Authors: Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi Takahashi, Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi TakahashiAbstract:The reaction of planar-chiral Cyclopentadienyl–ruthenium complexes with Bu4NI resulted in the formation of iodo complexes with high diastereoselectivity (up to >99%de). The stereochemistry of the ruthenium center in the starting material did not influence the diastereoselectivity of the products. Epimerization of a diastereomerically pure sample gave a mixture of two diastereomers in the same ratio as with the ligand-exchange reaction, suggesting that the selectivity is determined by the difference in thermodynamic stability between the diastereomeric pair of iodo complexes. The ratio of the products depends on the nature of the substituent on the Cyclopentadienyl ring and P ligands on the ruthenium atom. A combination of small substituents on the Cyclopentadienyl group and small P ligands with strong electron-donating ability favored the formation of 2-I. The bulkiness of the substituents on the Cyclopentadienyl group or of the P ligands, and low electron-donating ability of the P ligands increased the ratio of 2-II complexes to 2-I isomer.
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highly selective induction of metal centered chirality in the ligand exchange reaction of planar chiral Cyclopentadienyl ruthenium complex bearing an anchor phosphine ligand
Chemical Communications, 2001Co-Authors: Kiyotaka Onitsuka, Yuji Matsushima, Noriko Dodo, Shigetoshi TakahashiAbstract:Treatment of planar-chiral Cyclopentadienyl–phosphine ruthenium complexes with phosphine and phosphite induces metal-centered chirality with a high stereoselectivity (≳99 % de).
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optical resolution of planar chiral Cyclopentadienyl rhodium and iron complexes by liquid chromatography using aqueous β cyclodextrin
Chemistry Letters, 1996Co-Authors: Yuma Morimoto, Kaori Ando, Mitsunari Uno, Shigetoshi TakahashiAbstract:Racemates of planar-chiral Cyclopentadienyl-rhodium and -iron complexes, Cp′Rh(cod) and Cp′Fe(CO)2Y (Cp′: trisubstituted Cyclopentadienyls, Y = alkyl or halogen) are optically resolved on a preparative scale into enantiomers with efficincies of 100 and 50%ee, respectively, by liquid chromatography on a polyamide column using aqueous β-cyclodextrin as a mobile phase.
Anthony Deally - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Cytotoxicity Studies of Silyl-Substituted Titanocene Dichloride Derivatives
Organometallics, 2012Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Helge Müller-bunz, Matthias TackeAbstract:Six new titanocene compounds have been isolated and characterized. These compounds were synthesized from their silyl-substituted fulvene or cyclopentadiene precursors using Super Hydride (LiBEt3H) or n-BuLi, followed by transmetalation with titanium tetrachloride, to yield the corresponding titanocene dichloride derivatives. These complexes are bis-[((phenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3a), bis-[((4-methoxyphenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3b), bis-[((4-N,N-dimethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3c), bis-[((4-N,N-diethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3d), bis-[((1-methyl-5-trimethylsilyl)indol-3-yl)methylCyclopentadienyl] titanium(IV) dichloride (4e), and bis-[((1-methyl-3-diethylaminomethyl-5-trimethylsilyl)indol-2-yl)methylCyclopentadienyl] titanium(IV) dichloride (4f). The two titanocenes 3a and 3b were crystallized and characterized by X-ray crystallography, while ...
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Synthesis and Cytotoxicity Studies of Silyl-Substituted Titanocene Dichloride Derivatives
2012Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Helge Müller-bunz, Matthias TackeAbstract:Six new titanocene compounds have been isolated and characterized. These compounds were synthesized from their silyl-substituted fulvene or cyclopentadiene precursors using Super Hydride (LiBEt3H) or n-BuLi, followed by transmetalation with titanium tetrachloride, to yield the corresponding titanocene dichloride derivatives. These complexes are bis-[((phenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3a), bis-[((4-methoxyphenyl)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3b), bis-[((4-N,N-dimethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3c), bis-[((4-N,N-diethylmethanamine)dimethylsilane)Cyclopentadienyl] titanium(IV) dichloride (3d), bis-[((1-methyl-5-trimethylsilyl)indol-3-yl)methylCyclopentadienyl] titanium(IV) dichloride (4e), and bis-[((1-methyl-3-diethylaminomethyl-5-trimethylsilyl)indol-2-yl)methylCyclopentadienyl] titanium(IV) dichloride (4f). The two titanocenes 3a and 3b were crystallized and characterized by X-ray crystallography, while all six titanocenes were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines in order to determine their IC50 values. Titanocenes were found to have IC50 values of 139 (±5), 106 (± 4), 127 (±4), 104 (±9), 90 (±6), and 15 (±2) μM
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synthesis and cytotoxicity studies of achiral azaindole substituted titanocenes
Heteroatom Chemistry, 2011Co-Authors: Luis Miguel Menéndez Méndez, Anthony Deally, Donal F Oshea, Matthias TackeAbstract:From the reaction of 1-methyl-1 H-pyr-rolo[2,3-b]pyridine (1a),1-(methoxymethyl)-1 H-pyrrolo[2,3-b]pyridine (1b), 1-isopropyl-1 H-pyrrolo[2,3-b]pyridine (1c), and 1-(4-methoxybenzyl)-1 H-pyrrolo[2,3-b]pyridine (1d) under Vilsmeier–Haak conditions, the corresponding aldehydes in position 3 (2a–2d) were synthesized. These aldehydes were transformed in the corresponding fulvenes (3a–3d) by the Knoevenagel condensation and treated with Li[BEt3H] to obtain the corresponding lithiated cyclopentadienide intermediates (3′a–3′d). These intermediates were, finally transmetallated to titanium with TiCl4 to yield the 7-azaindol-3-yl-substituted titanocenes bis {[(1-methyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl] Cyclopentadienyl} titanium(IV) dichloride (4a), bis{[(1-methoxymethyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl]Cyclopentadienyl} titanium(IV)dichloride (4b), bis{[(1-Isopropyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl]Cyclopentadienyl} titanium(IV) dichloride (4c), and bis{[(4-methoxybenzyl-1-H-pyrrolo[2,3-b]pyridin-3-yl)methyl]Cyclopentadienyl} titanium(IV) dichloride (4d). All the titanocenes had their cytotoxicity investigated through MTT-based preliminary in vitro testing on the Caki-1 cell lines to determinate their IC50 values. Titanocenes 4a–4c were found to have IC50 values of 120 ± 10, 83 ± 13, and 54 ± 12, µM respectively, whereas 4d showed no cytotoxic activity. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:148–157, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20668
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synthesis and preliminary cytotoxicity studies of achiral pyrrolyl substituted titanocenes
Polyhedron, 2010Co-Authors: Anthony Deally, James Claffey, Megan Hogan, Helge Mullerbunz, Brendan Gleeson, Siddappa A Patil, Donal F Oshea, Matthias TackeAbstract:From the reaction of various 6-indolylfulvenes (1a−f) with Super Hydride (LiBEt3H), followed by transmetalation with titanium tetrachloride (TiCl4), six indolyl-substituted titanocenes, bis[(1-methylindol-2-yl)Cyclopentadienyl]titanium(IV) dichloride (3a), bis[(1-methyl-5-methoxyindol-2-yl)Cyclopentadienyl]titanium(IV) dichloride (3b), a dihydrochloride derivative of bis[(1-methyl-3-dimethylaminomethylindol-2-yl)Cyclopentadienyl]titanium(IV) dichloride (3c), bis[(1-methylindol-3-yl)Cyclopentadienyl]titanium(IV) dichloride (3d), bis[(1-methyl-5-methoxyindol-3-yl)Cyclopentadienyl]titanium(IV) dichloride (3e), and bis[(1-methylmethoxyindol-3-yl)Cyclopentadienyl]titanium(IV) dichloride (3f), were obtained. The six titanocenes 3a−f were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines in order to determine their IC50 values. Titanocenes 3a−f were found to have IC50 values of 47 (±9), 15 (±2), 8.2 (±1.9), 21 (±5), 11 (±1), and 170 (±40) μM, respectively.
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Synthesis and Cytotoxicity Studies of Fluorinated Derivatives of Vanadocene Y
European Journal of Inorganic Chemistry, 2009Co-Authors: Brendan Gleeson, James Claffey, Megan Hogan, Anthony Deally, Helge Müller-bunz, Siddappa A Patil, Luis Miguel Menéndez Méndez, Denise Wallis, Matthias TackeAbstract:From the reaction of 6-(2-fluoro-4-methoxyphenyl)fulvene (1a), 6-(3-fluoro-4-methoxyphenyl)fulvene (1b) and 6-[4-(trifluoromethoxy)phenyl]fulvene (1c) with LiBEt3H, lithiated cyclopentadienide intermediates (2a–c) were synthesised. These intermediates were then transmetallated to vanadium with VCl4 to yield the benzyl-substituted vanadocenes bis[(2-fluoro-4-methoxybenzyl)Cyclopentadienyl]vanadium(IV) dichloride (3a), bis[(3-fluoro-4-methoxybenzyl)Cyclopentadienyl]vanadium(IV) dichloride (3b), and bis[(4-trifluoromethoxybenzyl)Cyclopentadienyl]vanadium(IV) dichloride (3c). The three vanadocenes 3a–c were characterised by single-crystal X-ray diffraction. All three vanadocenes had their cytotoxicity investigated through MTT-based preliminary in-vitro testing on the LLC-PK and Caki-1 cell lines in order to determine their IC50 values. Vanadocenes 3a–c were found to have IC50 values of 6.0 (+/–4), 35 (+/–7) and 13 (+/–3) μM on the LLC-PK cell line and IC50 values of 78 (+/–11), 18 (+/–16) and 2.2 (+/–0.5) μM on the Caki-1 cell line respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Yuji Matsushima - One of the best experts on this subject based on the ideXlab platform.
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diastereoselective oxidative addition of allyl chloride to planar chiral Cyclopentadienyl ruthenium complexes
Organometallics, 2004Co-Authors: Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi TakahashiAbstract:The reaction of planar-chiral Cyclopentadienyl−ruthenium complexes with allyl chloride at room temperature resulted in the diastereoselective formation of π-allyl−ruthenium complexes, in which the chirality at the Ru center depended on the substituent at the 4-position of the Cyclopentadienyl group. Epimerization at the Ru center of π-allyl complexes at 90 °C suggested that the diastereoselectivity was under kinetic control.
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stereoselective ligand exchange reaction of planar chiral Cyclopentadienyl ruthenium complexes thermodynamic control of configuration at a stereogenic metal center
Dalton Transactions, 2004Co-Authors: Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi Takahashi, Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi TakahashiAbstract:The reaction of planar-chiral Cyclopentadienyl–ruthenium complexes with Bu4NI resulted in the formation of iodo complexes with high diastereoselectivity (up to >99%de). The stereochemistry of the ruthenium center in the starting material did not influence the diastereoselectivity of the products. Epimerization of a diastereomerically pure sample gave a mixture of two diastereomers in the same ratio as with the ligand-exchange reaction, suggesting that the selectivity is determined by the difference in thermodynamic stability between the diastereomeric pair of iodo complexes. The ratio of the products depends on the nature of the substituent on the Cyclopentadienyl ring and P ligands on the ruthenium atom. A combination of small substituents on the Cyclopentadienyl group and small P ligands with strong electron-donating ability favored the formation of 2-I. The bulkiness of the substituents on the Cyclopentadienyl group or of the P ligands, and low electron-donating ability of the P ligands increased the ratio of 2-II complexes to 2-I isomer.
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highly selective induction of metal centered chirality in the ligand exchange reaction of planar chiral Cyclopentadienyl ruthenium complex bearing an anchor phosphine ligand
Chemical Communications, 2001Co-Authors: Kiyotaka Onitsuka, Yuji Matsushima, Noriko Dodo, Shigetoshi TakahashiAbstract:Treatment of planar-chiral Cyclopentadienyl–phosphine ruthenium complexes with phosphine and phosphite induces metal-centered chirality with a high stereoselectivity (≳99 % de).
Kiyotaka Onitsuka - One of the best experts on this subject based on the ideXlab platform.
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diastereoselective oxidative addition of allyl chloride to planar chiral Cyclopentadienyl ruthenium complexes
Organometallics, 2004Co-Authors: Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi TakahashiAbstract:The reaction of planar-chiral Cyclopentadienyl−ruthenium complexes with allyl chloride at room temperature resulted in the diastereoselective formation of π-allyl−ruthenium complexes, in which the chirality at the Ru center depended on the substituent at the 4-position of the Cyclopentadienyl group. Epimerization at the Ru center of π-allyl complexes at 90 °C suggested that the diastereoselectivity was under kinetic control.
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stereoselective ligand exchange reaction of planar chiral Cyclopentadienyl ruthenium complexes thermodynamic control of configuration at a stereogenic metal center
Dalton Transactions, 2004Co-Authors: Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi Takahashi, Yuji Matsushima, Kiyotaka Onitsuka, Shigetoshi TakahashiAbstract:The reaction of planar-chiral Cyclopentadienyl–ruthenium complexes with Bu4NI resulted in the formation of iodo complexes with high diastereoselectivity (up to >99%de). The stereochemistry of the ruthenium center in the starting material did not influence the diastereoselectivity of the products. Epimerization of a diastereomerically pure sample gave a mixture of two diastereomers in the same ratio as with the ligand-exchange reaction, suggesting that the selectivity is determined by the difference in thermodynamic stability between the diastereomeric pair of iodo complexes. The ratio of the products depends on the nature of the substituent on the Cyclopentadienyl ring and P ligands on the ruthenium atom. A combination of small substituents on the Cyclopentadienyl group and small P ligands with strong electron-donating ability favored the formation of 2-I. The bulkiness of the substituents on the Cyclopentadienyl group or of the P ligands, and low electron-donating ability of the P ligands increased the ratio of 2-II complexes to 2-I isomer.
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highly selective induction of metal centered chirality in the ligand exchange reaction of planar chiral Cyclopentadienyl ruthenium complex bearing an anchor phosphine ligand
Chemical Communications, 2001Co-Authors: Kiyotaka Onitsuka, Yuji Matsushima, Noriko Dodo, Shigetoshi TakahashiAbstract:Treatment of planar-chiral Cyclopentadienyl–phosphine ruthenium complexes with phosphine and phosphite induces metal-centered chirality with a high stereoselectivity (≳99 % de).
