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Kenneth M. Nicholas - One of the best experts on this subject based on the ideXlab platform.
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Preparation of [2,5-Diisopropylcyclohexane-1,4- bis(indenyl)]titanium Dichloride and [2,5-Diisopropylcyclohexane-1,4-bis(tetrahydroindenyl)]- titanium Dichloride and Their Comparison as Catalysts for the Enantioselective Pinacol Coupling of Benzaldeh
Organometallics, 2000Co-Authors: Ronald L. Halterman, Chengjiang Zhu, Zhouliang Chen, Melinda S. Dunlap, And Masood A. Khan, Kenneth M. NicholasAbstract:The nonracemic bis(indene) (+)-(1R,2R,4R,5R)-1,4-bis(3‘-indenyl)-2,5-diisopropylcyclohexane (10) was synthesized in 60% yield from the addition of indenyllithium to the corresponding bis(methanesulfonate) ester of 2,4-diisopropyl-1,4-cyclohexanediol. Deprotonation of bis(indene) 10 with n-BuLi followed by metalation with TiCl3 and oxidative workup (HCl, air, chloroform) gave the single stereoisomeric 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(indenyl)titanium Dichloride 3 in 80% yield. Attempts to form the corresponding bis(indenyl)zirconium Dichloride were unsuccessful. Catalytic hydrogenation of bis(indenyl)titanium Dichloride 3 gave the 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(tetrahydroindenyl)titanium Dichloride 4 in 76% yield. The solid-state structure of 4 was determined by X-ray crystallographic methods. Nonracemic mixtures of chiral bis(indenyl)titanium Dichloride 3 and bis(tetrahydroindenyl)titanium Dichloride 4 were examined as catalysts for the pinacol coupling of benzaldehyde in t...
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 Biological Evaluation of Achiral Indole-Substituted Titanocene Dichloride Derivatives
International journal of medicinal chemistry, 2012Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Matthias TackeAbstract:Six new titanocene compounds have been isolated and characterised. These compounds were synthesised from their fulvene precursors using Super Hydride (LiBEt3H) followed by transmetallation with titanium tetrachloride to yield the corresponding titanocene Dichloride derivatives. These complexes are bis-[((1-methyl-3-diethylaminomethyl)indol-2-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5a), bis-[((5-methoxy-1-methyl,3-diethylaminomethyl)indol-2-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5b), bis-[((1-methyl,3-diethylaminomethyl)indol-4-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5c), bis-[((5-bromo-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5d), bis-[((5-chloro-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5e), and bis-[((5-fluoro-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5f). All six titanocenes 5a–5f were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines using DMSO and Soluphor P as solubilising agents in order to determine their IC50 values. Titanocenes 5a–5f were found to have IC50 values of 10 (±2), 21 (±3), 29 (±4), 140 (±6), and 450 (±10) μM when tested using DMSO.
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Synthesis and cytotoxicity studies of methoxy benzyl substituted titanocenes
Journal of Organometallic Chemistry, 2008Co-Authors: James Claffey, Clara Pampillón, Megan Hogan, Helge Müller-bunz, Matthias TackeAbstract:Abstract From the reaction of 6(2-methoxy-phenyl)fulvene ( 1a ), 6(3-methoxy-phenyl)fulvene ( 1b ), 6(3,4-dimethoxy-phenyl)fulvene ( 1c ) and 6(3,4,5-trimethoxy-phenyl)fulvene ( 1d ) with LiBEt 3 H, lithiated cyclopentadienide intermediates 2a – d were synthesised. These intermediates were then transmetallated to titanium with TiCl 4 to give benzyl substituted titanocenes bis-[(2-methoxy-benzyl)cyclopentadienyl]titanium(IV) Dichloride ( 3a ), bis-[(3-methoxy-benzyl)cyclopentadienyl]titanium(IV) Dichloride ( 3b ), bis-[(3,4-dimethoxy-benzyl)cyclopentadienyl]titanium(IV) Dichloride ( 3c ) and bis-[(3,4,5-trimethoxy-benzyl)cyclopentadienyl]titanium(IV) Dichloride ( 3d ). The three titanocenes 3a – c were characterised by single crystal X-ray diffraction, while the structure of the fourth titanocene 3d was elucidated through a DFT calculation. All four titanocenes had their cytotoxicity investigated through preliminary in vitro testing on the LLC-PK (pig kidney epithelial) cell line in order to determine their IC 50 values. Titanocenes 3a – d were found to have IC 50 values of 97, 159, 88 and 253 μM, respectively. All four titanocene derivatives show significant cytotoxicity improvement when compared to unsubstituted titanocene Dichloride.
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The synthesis and cytotoxic evaluation of a series of benzodioxole substituted titanocenes
Applied Organometallic Chemistry, 2007Co-Authors: Nigel J. Sweeney, Katja Strohfeldt, Clara Pampillón, James Claffey, Helge Müller-bunz, Matthias TackeAbstract:Using 6-benzo[1,3]dioxolefulvene (1a), a series of benzodioxole substituted titanocenes was synthesized. The benzyl-substituted titanocene bis[(benzo[1,3]dioxole)-5-methylcyclopentadienyl] titanium (IV) Dichloride (2a) was synthesized from the reaction of Super Hydride with 1a. An X-ray determined crystal structure was obtained for 2a. The ansa-titanocene (1,2-di(cyclopentadienyl)1,2-di-(benzo[1,3]dioxole)-ethanediyl) titanium(IV) Dichloride (2b) was synthesized by reductive dimerisation of la with titanium Dichloride. The diarylmethyl substituted titanocene bis(di(benzo[1,3]dioxole)-S-methylcyclopentadienyl) titanium(IV) Dichloride (20 was synthesized by reacting la with the para-lithiated benzodioxole followed by transmetallation with titanium tetrachloride. When titanocenes 2a-c were tested against pig kidney (LLC-PK) cells inhibitory concentrations (IC50) of 2.8 X 10(-4), 1.6 x 10(-4) and 7.6 x 10(-5) m, respectively, were observed. These values represent improved cytotoxicity against LLC-PK, when compared with unsubstituted titanocene Dichloride, but are not as impressive as values obtained for titanocenes previously synthesized using the above methods. Copyright (c) 2006 John Wiley & Sons, Ltd.
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novel titanocene anti cancer drugs derived from fulvenes and titanium Dichloride
Journal of Organometallic Chemistry, 2004Co-Authors: Matthias Tacke, Franzjosef K Rehmann, Lorcan T Allen, Laurence P Cuffe, Helge Mullerbunz, William M Gallagher, Oscar Mendoza, Nigel J. SweeneyAbstract:AbstractStarting from 6-(p N;N-dimethylanilinyl)fulvene (1a) or 6-(pentamethylphenyl)fulvene (1b) [1,2-di(cyclopentadienyl)-1,2-di(p N;N-dimethylaminophenyl)ethanediyl] titanium Dichloride (2a) and [1,2-di(cyclopentadienyl)-1,2-bis(pentamethylphe-nyl)ethanediyl] titanium Dichloride (2b) and their corresponding dithiocyanato complexes (3a, 3b) were synthesized. Titanocene 2bdid not show a cytotoxic effect, but when 2a was tested against pig kidney carcinoma cells (LLC-PK) or human ovarian carcinomacells (A2780/cp70) inhibitory concentrations (IC 50 ) of 2.7 10 4 and 1.9 10 4 M, respectively, were observed. 2004 Elsevier B.V. All rights reserved. Keywords: Anti-cancer drug; cis-Platinum; Titanocene; Fulvene; LLC-PK; A2780/cp70 1. IntroductionDespite the resounding success of cis-platinum andclosely related platinum anti-tumor agents, the move-ment of other transition-metal anti-cancer drugs to-wards the clinic has been exceptionally slow [1–3].Metallocene Dichlorides (Cp 2 MCl 2 )withM¼Ti, V, Nband Mo show remarkable anti-tumor activity [4,5].However, only titanocene Dichloride has reached Phase Iclinical trials so far, with a maximum tolerable dose of315 mg/m
Ronald L. Halterman - One of the best experts on this subject based on the ideXlab platform.
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Preparation of [2,5-Diisopropylcyclohexane-1,4- bis(indenyl)]titanium Dichloride and [2,5-Diisopropylcyclohexane-1,4-bis(tetrahydroindenyl)]- titanium Dichloride and Their Comparison as Catalysts for the Enantioselective Pinacol Coupling of Benzaldeh
Organometallics, 2000Co-Authors: Ronald L. Halterman, Chengjiang Zhu, Zhouliang Chen, Melinda S. Dunlap, And Masood A. Khan, Kenneth M. NicholasAbstract:The nonracemic bis(indene) (+)-(1R,2R,4R,5R)-1,4-bis(3‘-indenyl)-2,5-diisopropylcyclohexane (10) was synthesized in 60% yield from the addition of indenyllithium to the corresponding bis(methanesulfonate) ester of 2,4-diisopropyl-1,4-cyclohexanediol. Deprotonation of bis(indene) 10 with n-BuLi followed by metalation with TiCl3 and oxidative workup (HCl, air, chloroform) gave the single stereoisomeric 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(indenyl)titanium Dichloride 3 in 80% yield. Attempts to form the corresponding bis(indenyl)zirconium Dichloride were unsuccessful. Catalytic hydrogenation of bis(indenyl)titanium Dichloride 3 gave the 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(tetrahydroindenyl)titanium Dichloride 4 in 76% yield. The solid-state structure of 4 was determined by X-ray crystallographic methods. Nonracemic mixtures of chiral bis(indenyl)titanium Dichloride 3 and bis(tetrahydroindenyl)titanium Dichloride 4 were examined as catalysts for the pinacol coupling of benzaldehyde in t...
Zhouliang Chen - One of the best experts on this subject based on the ideXlab platform.
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Preparation of [2,5-Diisopropylcyclohexane-1,4- bis(indenyl)]titanium Dichloride and [2,5-Diisopropylcyclohexane-1,4-bis(tetrahydroindenyl)]- titanium Dichloride and Their Comparison as Catalysts for the Enantioselective Pinacol Coupling of Benzaldeh
Organometallics, 2000Co-Authors: Ronald L. Halterman, Chengjiang Zhu, Zhouliang Chen, Melinda S. Dunlap, And Masood A. Khan, Kenneth M. NicholasAbstract:The nonracemic bis(indene) (+)-(1R,2R,4R,5R)-1,4-bis(3‘-indenyl)-2,5-diisopropylcyclohexane (10) was synthesized in 60% yield from the addition of indenyllithium to the corresponding bis(methanesulfonate) ester of 2,4-diisopropyl-1,4-cyclohexanediol. Deprotonation of bis(indene) 10 with n-BuLi followed by metalation with TiCl3 and oxidative workup (HCl, air, chloroform) gave the single stereoisomeric 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(indenyl)titanium Dichloride 3 in 80% yield. Attempts to form the corresponding bis(indenyl)zirconium Dichloride were unsuccessful. Catalytic hydrogenation of bis(indenyl)titanium Dichloride 3 gave the 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(tetrahydroindenyl)titanium Dichloride 4 in 76% yield. The solid-state structure of 4 was determined by X-ray crystallographic methods. Nonracemic mixtures of chiral bis(indenyl)titanium Dichloride 3 and bis(tetrahydroindenyl)titanium Dichloride 4 were examined as catalysts for the pinacol coupling of benzaldehyde in t...
Chengjiang Zhu - One of the best experts on this subject based on the ideXlab platform.
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Preparation of [2,5-Diisopropylcyclohexane-1,4- bis(indenyl)]titanium Dichloride and [2,5-Diisopropylcyclohexane-1,4-bis(tetrahydroindenyl)]- titanium Dichloride and Their Comparison as Catalysts for the Enantioselective Pinacol Coupling of Benzaldeh
Organometallics, 2000Co-Authors: Ronald L. Halterman, Chengjiang Zhu, Zhouliang Chen, Melinda S. Dunlap, And Masood A. Khan, Kenneth M. NicholasAbstract:The nonracemic bis(indene) (+)-(1R,2R,4R,5R)-1,4-bis(3‘-indenyl)-2,5-diisopropylcyclohexane (10) was synthesized in 60% yield from the addition of indenyllithium to the corresponding bis(methanesulfonate) ester of 2,4-diisopropyl-1,4-cyclohexanediol. Deprotonation of bis(indene) 10 with n-BuLi followed by metalation with TiCl3 and oxidative workup (HCl, air, chloroform) gave the single stereoisomeric 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(indenyl)titanium Dichloride 3 in 80% yield. Attempts to form the corresponding bis(indenyl)zirconium Dichloride were unsuccessful. Catalytic hydrogenation of bis(indenyl)titanium Dichloride 3 gave the 2,5-diisopropylcyclohexane-1,4-diyl-bridged bis(tetrahydroindenyl)titanium Dichloride 4 in 76% yield. The solid-state structure of 4 was determined by X-ray crystallographic methods. Nonracemic mixtures of chiral bis(indenyl)titanium Dichloride 3 and bis(tetrahydroindenyl)titanium Dichloride 4 were examined as catalysts for the pinacol coupling of benzaldehyde in t...
