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    Advanced-designed Ru(II) complexes containing phosphinite ligands derived from chiral amino alcohols: Electrochemical behavior, DFT calculations, and biological activity
    (Elsevier Science Sa, 2025) Meric, Nermin; Isik, Ugur; Dauletbakov, Anuar; Zolotareva, Darya; Zazybin, Alexey; Sever, Mehmet Serif; Okumus, Veysi
    We report two phosphinite ligands derived from chiral amino alcohols, and their complexes with ruthenium(II). These compounds were characterized by spectroscopic methods. Then, antimicrobial, antioxidant, and DNA binding activities of the chiral Ru(II)-phosphinite complexes were tested. Complex (1R)-2-{benzyl[(1S)-1(naphthalen-1-yl)ethyl]amino}-1-phenylethyl diphenylphos- phinito[dichloro(eta 6-p-cymene)ruthenium(II)], 7 showed both the highest radical scavenging activity (90.93 +/- 0.98 %) and the highest metal chelating activity (65.45 +/- 1.46 %) at 200.0 mg l-1 concentration. In addition, all of complexes had different rates of binding activity to calf thymus DNA (CT-DNA). Moreover, extensive theoretical and experimental investigations were conducted to gain a more profound understanding of the chemical descriptors and the diverse electronic transitions taking place within the ruthenium complexes, as well as their electrochemical characteristics.
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    Applications of transition metal complexes containing 3,3?-bis(diphenylphosphinoamine)-2,2?-bipyridine ligand to transfer hydrogenation of ketones
    (Elsevier Science Sa, 2012) Aydemir, Murat; Meric, Nermin; Baysal, Akin
    Hydrogen transfer reduction processes are attracting increasing interest from synthetic chemists in view of their operational simplicity. 3,3'-bis(diphenylphosphinoamine)-2,2'-bipyridine, (Ph2PNH)(2)C10H6N2, was prepared through a single step reaction of 3,3'-diamino-2,2'-bipyridine with diphenyl-chlorophosphine. Reaction of (Ph2PNH)(2)C10H6N2 with [Ru(eta(6)-benzene)(mu-Cl)Cl](2), [Rh(mu-Cl)(cod)](2) or [Ir(eta(5)-C5Me5)(mu-Cl)Cl](2) gave a range of new bridged dinuclear complexes (C10H6N2{NHPPh2Ru(eta(6)-benzene)Cl-2}(2)], 1, [C10H6N2{PPh2NHRh(cod)Cl}(2)], 2 and [C10H6N2{NHPPh2Ir(eta(5)-C5Me5)Cl-2}(2)], 3, respectively. All new complexes have been fully characterized by analytical and spectroscopic methods. (HP)-H-1-P-31{H-1} NMR, (HC)-H-1-C-13 HETCOR or (HH)-H-1-H-1 COSY correlation experiments were used to confirm the spectral assignments. 1, 2 and 3 are suitable catalyst precursors for the transfer hydrogenation of acetophenone derivatives. Notably [Ru((Ph2PNH)(2)C10H6N2)(eta(6)-benzene)Cl-2], 1 acts as an excellent catalyst, giving the corresponding alcohols in 98-99% yields in 10 min at 82 degrees C (TOF <= 600 h(-1)) for the transfer hydrogenation reaction in comparison to analogous rhodium or iridium complexes. This transfer hydrogenation is characterized by low reversibility under these conditions. (C) 2012 Elsevier B.V. All rights reserved.
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    Asymmetric transfer hydrogenation of acetophenone derivatives with novel chiral phosphinite based ?6-p-cymene/ruthenium(II) catalysts
    (Elsevier Science Sa, 2011) Aydemir, Murat; Meric, Nermin; Baysal, Akin; Turgut, Yilmaz; Kayan, Cezmi; Seker, Sevil; Togrul, Mahmut
    Enantioselective reduction of prochiral ketones to optically active secondary alcohols is an important subject in synthetic organic chemistry because the resulting chiral alcohols are extremely useful, biologically active compounds. The new chiral ligands (2R)-2-[benzyl{(2-((diphenylphosphanyl)oxy)ethyl)}amino]butyldiphenylphosphinite, 1 and (2R)-2-[benzyl{(2-((dicyclohexylphosphanyl)oxy)ethyl)}amino]butyldicyclohexylphosphinite, 2 and the corresponding ruthenium(II) complexes 3 and 4 have been prepared. The structures of these complexes have been elucidated by a combination of multinuclear NMR spectroscopy, IR spectroscopy and elemental analysis. P-31-{H-1} NMR, DEPT, H-1-C-13 HETCOR or H-1-H-1 COSY correlation experiments were used to confirm the spectral assignments. These ruthenium(II) ephosphinite complexes have been used as catalysts for the asymmetric transfer hydrogenation of acetophenone derivatives. Under optimized conditions, aromatic ketones were reduced in good conversions and in moderate to good enantioselectivities (up to 85% ee). (C) 2011 Elsevier B. V. All rights reserved.
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    Asymmetric transfer hydrogenation of aromatic ketones with the ruthenium(II) catalyst derived from C2 symmetric N,N?-bis[(1S)-1-benzyl-2-O-(diphenylphosphinite)ethyl]ethanediamide
    (Elsevier Science Sa, 2010) Aydemir, Murat; Meric, Nermin; Durap, Feyyaz; Baysal, Akin; Togrul, Mahmut
    Asymmetric transfer hydrogenation of ketones with chiral molecular catalysts is realized to be one of the most magnificent tools to access chiral alcohols in organic synthesis. A new chiral phosphinite compound N,N'-bis[(1S)-1-benzyl-2-O-(diphenylphosphinite)ethyl]ethanediamide (1), has been synthesized by the reaction of chlorodiphenylphosphine with N,N'-bis[(1S)-1-benzyl-2-hydroxyethyl]ethanediamide under argon atmosphere. The oxidation of 1 with aqueous hydrogen peroxide, elemental sulfur or grey selenium in toluene gave the corresponding oxide 1a, sulfide 1b and selenide 1c, respectively. Pd, Pt and Ru complexes were obtained by the reaction of 1 with [MCl2(cod)] (M: Pd 1d, Pt 1e) and [Ru(p-cymene)Cl-2](2) 1f, respectively. All these new complexes were characterized by using NMR, FT-IR spectroscopies and microanalysis. Additionally, as a demonstration of their catalytic reactivity, the ruthenium complex 1f was tested as catalyst in the asymmetric transfer hydrogenation reactions of acetophenone derivatives with iPrOH was also investigated. (C) 2010 Elsevier B.V. All rights reserved.
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    Boron containing chiral Schiff bases: Synthesis and catalytic activity in asymmetric transfer hydrogenation (ATH) of ketones
    (Elsevier, 2020) Pasa, Salih; Arslan, Nevin; Meric, Nermin; Kayan, Cezmi; Bingul, Murat; Durap, Feyyaz; Aydemir, Murat
    Asymmetric Transfer Hydrogenation (ATH) has been an attractive way for the reduction of ketones to chiral alcohols. A great number of novel and valuable synthetic pathways have been achived by the combination usage of organometallic and coordination chemistry for the production of important class of compounds and particularly optically active molecules. For this aim, four boron containing Schiff bases were synthesized by the reaction of 4-formylphenylboronic acid with chiral amines. The boron containing structures have been found as stable compounds due to the presence of covalent B-O bonds and thus could be handled in laboratory environment. They were characterized by H-1 NMR and FT-IR spectroscopy and elemental analysis and they were used as catalyst in the transfer hydrogenation of ketones to the related alcohol derivatives with high conversions (up to 99%) and low enantioselectivities (up to 22% ee). (C) 2019 Elsevier B.V. All rights reserved.
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    Catalysts for the asymmetric transfer hydrogenation of various ketones from [3-[(2S)-2-[(diphenylphosphanyl)oxy]-3-phenoxypropyl]-1-methyl-1H-imidazol-3-ium chloride] and [Ru(?6-arene)(?-Cl)Cl]2, Ir(?5-C5Me5)(?-Cl)Cl]2 or [Rh(?-Cl)(cod)]2
    (Elsevier Science Sa, 2019) Meric, Nermin; Arslan, Nevin; Kayan, Cezmi; Rafikov, Khadichakhan; Zazybin, Alexey; Kerimkulova, Aygul; Aydemir, Murat
    The combination of [3-[(2S)-2-[(diphenylphosphanyl)oxy]-3-phenoxypropyl]-1-methyl-1H-imidazol-3-ium chloride] with [Ru(eta(6)-arene)(mu-Cl)Cl](2), Ir(eta(5)-C5Me5)(mu-Cl)Cl](2) or [Rh(mu-Cl)(cod)](2), in the presence of KOH/isoPrOH, has been found to generate catalysts that are capable of enantioselectively reducing alkyl, aryl ketones to the corresponding (R)-alcohols. Under optimized conditions, when the catalysts were applied to the asymmetric transfer hydrogenation, we obtained the secondary alcohol products in high conversions and enantioselectivities using only 0.5 mol% catalyst loading. In addition, [3-[(2S)-2-{[(chloro(eta(4)-1,5-cyclooctadiene)rhodium)diphenyl phosphanyl] oxy}-3-phenoxypropyl]-1-methyl-1H-imidazol-3-ium chloride], (6) complex is much more active than the other analogous complexes in the transfer hydrogenation. Catalyst 6 acts as excellent catalysts, giving the corresponding (R)-1-phenyl ethanol in 99% conversion in 30 min (TOF <= 396 h(-1)) and in high enantioselectivity (92% ee).
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    Chiral phosphinites as efficient ligands for enantioselective Ru(II), Rh(I) and Ir(III)-catalyzed transfer hydrogenation reactions
    (Springer, 2017) Baysal, Akin; Karakas, Duygu Elma; Meric, Nermin; Ak, Bunyamin; Aydemir, Murat; Durap, Feyyaz
    Metal-catalyzed enantioselective transfer reduction of ketones to enantiomerically enriched chiral alcohols has recently attracted attention. Therefore, a series of methyl alkyl or alkyl/aryl ketones have been reduced by using Ru(II), Rh(I) and Ir(III) catalysts based on C (2)-symmetric chiral ferrocenyl phosphinite ligands. The corresponding optically active secondary alcohols were obtained in excellent conversions and moderate-to-good enantioselectivities. The best results were obtained with an iridium catalyst, giving up to 98% conversion and 80% ee.
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    Enantioselective transfer hydrogenation of various ketones with novel efficient iridium(III) ferrocenyl-phosphinite catalysts
    (Elsevier Science Sa, 2016) Meric, Nermin; Aydemir, Murat
    The asymmetric reduction of prochiral ketones is a pivotal reaction for the preparation of chiral alcohols which form an extremely important class of intermediates for fine chemicals and pharmaceuticals. Especially, iridium-based asymmetric reduction of ketones to enantiomerically enriched alcohols has recently attracted important attention by a number of research groups and interest in this area is growing. Therefore, a series of novel neutral mononuclear iridium(III) ferrocenyl-phosphinite complexes have been prepared and applied in the iridium(III)-catalyzed asymmetric transfer hydrogenation (ATH) of ketones to give corresponding secondary alcohols with outstanding enantioselectivities and reactivities using 2-propanol as the hydrogen source (up to 99% ee and 99% conversion). It was seen that the substituents on the backbone of the ligands resulted in a significant effect on both the activity and % enantioselectivity. Furthermore, the structural elucidation of the complexes was carried out by elemental analysis, IR and multi-nuclear NMR spectroscopic data. (C) 2016 Elsevier B.V. All rights reserved.
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    The first application of C2-symmetric ferrocenyl phosphinite ligands for rhodium-catalyzed asymmetric transfer hydrogenation of various ketones
    (Elsevier Science Sa, 2015) Ak, Bunyamin; Aydemir, Murat; Durap, Feyyaz; Meric, Nermin; Baysal, Akin
    Homogeneous catalysis has been responsible for many major recent developments in synthetic organic chemistry. The combined use of organometallic and coordination chemistry has produced a number of new and powerful synthetic methods for important classes of compounds in general and for optically active substances in particular. For this aim, a new class of chiral modular C-2-symmetric ferrocenyl phosphinite ligands has been prepared in good yields by using the inexpensive 1,1'-ferrocenedicarboxyaldehyde and various ferrocene based-amino alcohols as starting materials, and applied in the rhodium(I)-catalyzed asymmetric transfer hydrogenation (ATH) of aromatic ketones to give corresponding secondary alcohols with excellent enantioselectivities and reactivities using isoPrOH as the hydrogen source (up to 99% conversion and 99% ee). The substituents on the backbone of the ligands are found to exhibit a remarkable effect on both the activity and % ee. The structures of these ligands and their complexes have been elucidated by a combination of multinuclear NMR spectroscopy, IR spectroscopy and elemental analysis. (C) 2015 Elsevier B.V. All rights reserved.
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    Fluorine/phenyl chelated boron complexes: Synthesis, fluorescence properties and catalyst for transfer hydrogenation of aromatic ketones
    (Elsevier Science Sa, 2014) Kilic, Ahmet; Aydemir, Murat; Durgun, Mustafa; Meric, Nermin; Ocak, Yusuf Selim; Keles, Armagan; Temel, Hamdi
    The synthesis of salen/salan ligands (L-1 and L-2) and their fluorine/phenyl chelated boron complexes [L(1,2)BF2] or [L(1,2)BPh2] is described in this paper. The fluorine/phenyl chelated boron complexes were synthesized from the reaction of BF3 center dot OEt2 or BPh3 with the corresponding ligands in different solvent. The boron complexes display high stability and can be handled in air due to the presence of coordinative B <- N and covalent B-O bonds in their structures. The salen/salan ligands (designated as salan, a saturated version of the corresponding salen ligands) and their fluorine/phenyl chelated boron complexes have been characterized by H-1, C-13 NMR and F-19 NMR spectra, elemental analysis, FT-IR spectra, UV-vis spectra, LC-MS spectra, melting point and fluorescence spectroscopy. The fluorescence efficiencies of BF2-chelate boron complexes are greatly improved compared to those of the BPh2-chelate boron analogs based on the same salen/salan ligands, probably due to the enhanced conjugation degree of the diphenyl boron chelation, which can effectively prevent molecular aggregation. The boron complexes [L(1,2)BF2] or [L(1,2)BPh2] were also applied to the transfer hydrogenation of aromatic ketones to the corresponding alcohol derivatives in the presence of iso-PrOH as the hydrogen source. Catalytic studies showed that all complexes are good catalytic precursors for transfer hydrogenation of aryl alkyl ketones in 0.1 M iso-PrOH solution. This transfer hydrogenation is characterized by low reversibility under these conditions. (C) 2014 Elsevier B.V. All rights reserved.
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    Half-sandwich ruthenium(II) and iridium(III) complexes of imidazole based phosphinite ligands: antioxidant and antibacterial activities as well as electrochemical properties
    (Wiley-V C H Verlag Gmbh, 2024) Isik, Ugur; Rafikova, Khadichakhan; Meric, Nermin; Guzel, Remziye; Kerimkulova, Aygul; Akimbek, Arailym; Okumus, Veysi
    Ruthenium(II) and iridium(III) complexes of phosphinites including imidazole moiety were synthesized and characterized by microanalysis, IR, MS, and NMR spectroscopies. Antibacterial activity against Gram-positive and Gram-negative bacterial strains was assessed in all complexes. The highest radical scavenging (72.2 %) was obtained for [3-(3-chloro-2-({[dichloro(eta 6-benzene)ruthenium]diphenylphosphanyl}oxy)propyl)-1-butyl-1H-imidazol-3-ium chloride], 4 at 200 mu g/mL concentration, while [3-(3-chloro-2-({[dichloro(eta 5-pentamethylcyclopentadienyl)-iridium]diphenylphosphanyl}oxy)pro-pyl)-1-butyl-1H-imidazol-3-ium chloride], 6 demonstrated the highest antibacterial activity as 13 mm inhibition zone against E. hirea. Furthermore, optical and electrochemical featured of metal complexes containing imidazole phosphinite were investigated utilizing UV-vis absorption and cyclic voltammetry techniques. Consequently, all complexes can be proposed as metal-based charge convertible phosphinite complexes which may be employed as new generation and synergistic Dye-Sensitized Solar Cell (DSSC) materials. Ruthenium(II) and iridium(III) complexes of phosphinites including imidazole moiety are synthesized and characterized by microanalysis, IR, MS, and NMR spectroscopies. Their antibacterial activity against Gram-positive and Gram-negative bacterial strains is assessed. Furthermore, optical and electrochemical features of the metal complexes are investigated utilizing UV-vis absorption and cyclic voltammetry techniques. image
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    Highly efficient iridium catalysts based on C2-symmetric ferrocenyl phosphinite ligands for asymmetric transfer hydrogenations of aromatic ketones
    (Pergamon-Elsevier Science Ltd, 2015) Ak, Bunyamin; Aydemir, Murat; Durap, Feyyaz; Meric, Nermin; Elma, Duygu; Baysal, Alan
    A series of chiral modular C-2-symmetric ferrocenyl phosphinite ligands have been synthesized in good yields by using 1,1'-ferrocenedicarboxyaldehyde and various amino alcohols as starting materials, and applied in the iridium(III)-catalyzed asymmetric transfer hydrogenations of aromatic ketones to give the corresponding secondary alcohols with good enantioselectivities and reactivities using 2-propanol as the hydrogen source (up to 98% ee and 99% conversion). The substituents on the backbone of the ligands were found to have a significant effect on both the activity and enantiomeric excess. The structures of these complexes have been clarified by a combination of multinuclear NMR spectroscopy, IR spectroscopy, and elemental analysis. (C) 2015 Elsevier Ltd. All rights reserved.
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    Imine containing C2-Symmetric chiral half sandwich ?6-p-cymene-Ru(II)- phosphinite complexes: Investigation of their catalytic activity in the asymmetric transfer hydrogenation of ketones
    (Elsevier, 2020) Saleh, Najmuldain Abdullah; Pasa, Salih; Kayan, Cezmi; Meric, Nermin; Sunkur, Murat; Aral, Tarik; Aydemir, Murat
    New chiral C-2-symmetric bis(phosphinite) ligands containing imine group were synthesized from 1-({[(1R,2R)-2-{[(2-hydroxynaphthalen-1-yl)methylidene] amino}cyclohexyl]- imino}methyl)- naphthalen-2-ol and two equivalents of Ph2PCl, (i-Pr)(2)PCl or (Cy)(2)PCl, in high yields. Binuclear C-2-symmetric half sandwich eta(6)-p-cymene-Ru(II) complexes of the chiral phosphinite ligands were synthesized by treating of [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2) with the phosphinites in 1:1 M ratio in CH2Cl2. Their catalytic activities in asymmetric transfer hydrogenation (ATH) were investigated for the reaction of acetophenone derivatives with isopropyl alcohol. The corresponding optically active secondary alcohols were obtained in excellent levels of conversion (96-99%) and moderate enantioselectivity (up to 60% ee). Among three complexes investigated, complex 4 was the most efficient one. (C) 2019 Elsevier B.V. All rights reserved.
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    Ionic liquid based Ru(II)-phosphinite compounds and their catalytic use in transfer hydrogenation: X-ray structure of an ionic compound 1-chloro-3-(3-methylimidazolidin-1-yl)propan-2-ol
    (Pergamon-Elsevier Science Ltd, 2014) Aydemir, Murat; Rafikova, Khadichakhan; Kystaubayeva, Nurzhamal; Pasa, Salih; Meric, Nermin; Ocak, Yusuf Selim; Zazybin, Alexey
    The compound 1-chloro-3-(3-methylimidazolidin-1-yl)propan-2-ol chloride (1) was prepared from the reaction of 1-methylimidazole with epichlorohydrine. The corresponding phosphinite ligands were synthesized by the reaction 1-chloro-3-(3-methylimidazolidin-1-yl)propan-2-ol chloride, [C7H15N2OCl]Cl with one equivalent of chlorodiphenylphosphine or chlorodicyclohexylphosphine, in anhydrous CH2Cl2 and under an inert argon atmosphere. [Ru(eta(6)-arene)(mu-Cl)Cl](2) dimers readily react with the phosphinite ligands [(Ph2PO)-C7H14N2Cl]Cl (2) or [(Cy2PO)-C7H14N2Cl]Cl (3) at room temperature to afford the cationic derivatives [Ru((Ph2PO)-C7H14N2Cl)(eta(6)-arene)Cl-2]Cl and [Ru((Cy2PO)-C7H14N2Cl)(eta(6)-arene)Cl-2]Cl {arene: benzene (4), (5); p-cymene (6), (7)}. The structures of these ligands and their corresponding complexes have been elucidated by a combination of multinuclear NMR and IR spectroscopy, TGA/DTA and elemental analysis. The molecular structure of the ionic compound 1 was also determined by an X-ray single crystal diffraction study. Furthermore, the catalytic activity of complexes 4-7 for the transfer hydrogenation of various ketones was investigated and these complexes were found to be efficient catalysts in the transfer hydrogenation of various ketones, with excellent conversions up to 99%. Specifically, [Ru((Cy2PO)-C7H14N2Cl)(eta(6)-benzene)Cl-2]Cl (5) and [Ru((Cy2PO)-C7H14N2Cl)(eta(6)-p-cymene)Cl-2]Cl (7) act as excellent catalysts, giving the corresponding alcohols in 98-99% conversions in 5 min (TOF <= 1188 h(-1)). (C) 2014 Elsevier Ltd. All rights reserved.
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    A modular design of ruthenium(II) catalysts with chiral C2-symmetric phosphinite ligands for effective asymmetric transfer hydrogenation of aromatic ketones
    (Pergamon-Elsevier Science Ltd, 2010) Aydemir, Murat; Meric, Nermin; Baysal, Akin; Gumgum, Bahattin; Togrul, Mahmut; Turgut, Yilmaz
    Hydrogen-transfer reduction processes are attracting increasing interest from synthetic chemists in view of their operational simplicity. The new chiral C-2-symmetric ligands N,N'-bis-[(1S)-1-sec-butyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 1 and N,N'-bis-[(1S)-1-phenyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 2 and the corresponding ruthenium complexes 3 and 4 have been prepared and their structures have been elucidated by a combination of multi-nuclear NMR spectroscopy, IR spectroscopy, and elemental analysis. H-1-P-31 NMR, DEPT, H-1-C-13 HETCOR, or H-1-H-1 COSY correlation experiments were used to confirm the spectral assignments. The catalytic activity of complexes 3 and 4 in transfer hydrogenation of acetophenone derivatives by iso-PrOH has also been studied. Under optimized conditions, these chiral ruthenium complexes serve as catalyst precursors for the asymmetric transfer hydrogenation of acetophenone derivatives in iso-PrOH and act as excellent catalysts, giving the corresponding chiral alcohols in 99% yield and up to 75% ee. This transfer hydrogenation is characterized by low reversibility under these conditions. (C) 2010 Elsevier Ltd. All rights reserved.
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    New active ruthenium(II) complexes based N3,N3?-bis(diphenylphosphino)-2,2?-bipyridine-3,3?-diamine and P,P?-diphenylphosphinous acid-P,P?-[2,2?-bipyridine]-3,3?-diyl ester ligands for transfer hydrogenation of aromatic ketones by propan-2-ol
    (Elsevier Science Sa, 2009) Aydemir, Murat; Baysal, Akin; Meric, Nermin; Gumgum, Bahattin
    The dimeric starting material [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2) reacts with N3,N3'-bis(diphenylphosphino)-2,2'-bipyridine-3,3'-diamine, 1 and P,P'-diphenylphosphinous acid-P,P'-[2,2'-bipyridine]-3,3'-diyl ester, 2 ligands to afford bridged dinuclear complexes [C10H6N2{NHPPh2-Ru(eta(6)-p-cymene)Cl-2}(2)], 3 and [C10H6N2{OPPh2-Ru(eta(6)-p-cymene)Cl-22], 4 in quantitative yields. These bis(aminophosphine) and bis(phosphinite) based Ru(II) complexes serve as active catalyst precursors for the transfer hydrogenation of acetophenone derivatives in 2-propanol and especially 4 acts as a good catalyst, giving the corresponding alcohols in 99% yield in 20 min (TOF <= 280 h(-1)). (C) 2009 Elsevier B.V. All rights reserved.
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    New chiral ruthenium(II)-phosphinite complexes containing a ferrocenyl group in enantioselective transfer hydrogenations of aromatic ketones
    (Pergamon-Elsevier Science Ltd, 2013) Ak, Bunyamin; Elma, Duygu; Meric, Nermin; Kayan, Cezmi; Isik, Ugur; Aydemir, Murat; Durap, Feyyaz
    A new and versatile class of unsymmetrical ferrocenyl-phosphinite ligands possessing a stereogenic center has been prepared from commercially available, inexpensive aminoacids such as, D-, L-phenylglycine and D-, L-phenylalanine, through a concise synthetic procedure. These ligands are not very sensitive to air and moisture, and display good enantioselectivities in the ruthenium-catalyzed asymmetric transfer hydrogenation of acetophenone derivatives, in which up to 91% ee was obtained. A comparison of the catalytic properties of amino alcohols and other analogues based on a ferrocenyl backbone is also discussed briefly. The structures of these ligands and their corresponding complexes have been elucidated by a combination of multinuclear NMR spectroscopy, IR spectroscopy, and elemental analysis. (C) 2013 Elsevier Ltd. All rights reserved.
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    A new class of well-defined ruthenium catalysts for enantioselective transfer hydrogenation of various ketones
    (Elsevier Science Sa, 2018) Kayan, Cezmi; Meric, Nermin; Rafikova, Khadichakhan; Zazybin, Alexey; Gurbuz, Nevin; Karakaplan, Mehmet; Aydemir, Murat
    A pair of novel optically pure phosphinite ligands were synthesized by ring opening reaction of chiral amines with (R)-styrene oxide or (S)-glycidyl phenyl ether oxide using a straightforward method in high yields and their ruthenium complexes were described in detail. The ruthenium complexes proved to be highly efficient catalysts for the enantioselective hydrogenation of ketones, affording products up to 99% ee. The results showed that the corresponding chiral alcohols could be obtained with high activity and excellent enantioselectivities at the desired temperature. (2S)-1-{benzyl[(1S)-1-(naphthalen-1-yl)ethyl]amino}-3-phenoxypropan-2-yl diphenylphosphinito[dichloro(eta(6)-benzene)ruthenium (II)] acts an excellent catalyst in the reduction of ketones, giving the corresponding alcohol up to 99% ee. (C) 2018 Elsevier B.V. All rights reserved.
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    New functional chiral P-based ligands and application in ruthenium-catalyzed enantioselective transfer hydrogenation of ketones
    (Pergamon-Elsevier Science Ltd, 2017) Meric, Nermin; Kayan, Cezmi; Gurbuz, Nevin; Karakaplan, Mehmet; Binbay, Nil Ertekin; Aydemir, Murat
    Metal-catalyzed asymmetric transfer hydrogenation is a powerful and practical method for the reduction of ketones to produce the corresponding secondary alcohols, which are valuable building blocks in the pharmaceutical, perfume, and agrochemical industries. Hence, a series of novel chiral beta-amino alcohols were synthesized by chiral amines with regioselective ring opening of (S)-propylene oxide or reaction with (S)-(+)-2-hydroxypropyl p-toluenesulfonate by a straightforward method. The chiral ruthenium catalytic systems generated from [Ru(arene)(mu-Cl)Cl](2) complexes and chiral phosphinite ligands based on amino alcohol derivatives were employed in asymmetric transfer hydrogenation of ketones to give the corresponding optically active alcohols; (2S)-1-([(2.9-2-[(diphenylphosphanypoxylpropyl][(1R)-1-phenylethyl]amino}propan-2-yldiphenylphosphinitobis[dichol-oro(eta(6)-benzene)ruthenium(II)] acts an excellent catalyst in the reduction of cl-naphthyl methyl ketone, giving the corresponding alcohol with up to 99% ee. The substituents on the backbone of the ligands were found to have a remarkable effect on both the conversion and enantioselectivity of the catalysts. Furthermore, this transfer hydrogenation is characterized by low reversibility under these conditions. (C) 2017 Elsevier Ltd. All rights reserved.
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    Novel neutral phosphinite bridged dinuclear ruthenium(II) arene complexes and their catalytic use in transfer hydrogenation of aromatic ketones: X-ray structure of a new Schiff base, N3,N3?-di-2-hydroxybenzylidene-[2,2?]bipyridinyl-3,3?-diamine
    (Elsevier, 2010) Aydemir, Murat; Durap, Feyyaz; Baysal, Akin; Meric, Nermin; Buldag, Ayseguel; Guemguem, Bahattin; Oezkar, Saim
    A novel Schiff base N3,N3'-di-2-hydroxybenzylidene-[2,2']bipyridinyl-3,3'-diamine, 1 was synthesized from condensation of salicylaldehyde with 3,3'-diamino-2,2'-bipyridine. Reaction of 1 with two equivalents of PPh2Cl in the presence of Et3N proceeds in toluene to give N3,N3'-di-2-(diphenylphosphino)benzylidene-[2,2']bipyridinyl-3,3'-diamine, 2 in quantitative yield. Ruthenium(II) dimers [Ru(eta(6)-arene)(mu-Cl)]Cl](2) readily react with phosphinite ligand [(Ph2PO)(2)-C24H16N4], 2 in toluene at room temperature, to afford the neutral derivatives [C24H16N4{OPPh2-Ru(eta(6)-arene)Cl-2}2] {arene: benzene 3, p-cymene, 4}. All the complexes were fully characterized by analytical and spectroscopic methods. P-31-{H-1} NMR, H-1-C-13 HETCOR or H-1-H-1 COSY correlation experiments were used to confirm the spectral assignments. Molecular structure of the Schiff base, 1 was also determined by X-ray single crystal diffraction study. The catalytic activity of complexes 3 and 4 in the transfer hydrogenation of acetophenone derivatives was tested. Stable ruthenium(II)-phosphinite complexes were found to be efficient catalysts in the transfer hydrogenation of aromatic ketones in excellent conversions up to 99% (up to 530 per hour) in the presence of iso-PrOH/KOH. (C) 2010 Elsevier B.V. All rights reserved.