Yazar "Meric, Nermin" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • Küçük Resim Yok
    Öğe
    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.
  • Küçük Resim Yok
    Öğe
    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.
  • Küçük Resim Yok
    Öğe
    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.
  • Küçük Resim Yok
    Öğe
    Ruthenium, rhodium and iridium complexes of the furfuryl-2-(N-diphenylphosphino)methylamine ligand: Molecular structure and catalytic activity
    (Pergamon-Elsevier Science Ltd, 2012) Kayan, Cezmi; Meric, Nermin; Aydemir, Murat; Baysal, Akin; Elma, Duygu; Ak, Bunyamin; Sahin, Ertan
    The reaction of furfurylamine with two equivalents of PPh2Cl in the presence of Et3N affords furfuryl-2-(N,N-bis(diphenylphosphino)amine), (Ph2P)(2)NCH2-C4H3O (1). The corresponding ruthenium(II) complex trans-[Ru((PPh2)(2)NCH2-C4H3O)(2)Cl-2] (3) was synthesized by reacting 1 with [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2). The reaction of furfurylamine with one equivalent of PPh2Cl gives Ph2PNHCH2-C4H3O (2). The reaction of 2 with [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2), [Ru(eta(6)-benzene)(mu-Cl)Cl](2), [Rh(mu-Cl)(cod)](2) and [Ir(eta(5)-C5Me5)(mu-Cl)Cl](2) yields the complexes [Ru(Ph2PNHCH2-C4H3S)(eta(6)-p-cymene)Cl-2] (4), [Ru(Ph2PNHCH2-C4H3O)(eta(6-)benzene)Cl-2] (5), [Rh(Pb2PNHCH2-C4H3O)(cod)Cl] (6) and [Ir(Ph2PNHCH2-C4H3O)(eta(5)-C5Me5)Cl-2] (7), respectively. All the complexes were isolated from the reaction solution and fully characterized by analytical and spectroscopic methods. The structure of [Ru(Ph2PNHCH2-C4H3O)(eta(6)-p-cymene)Cl-2] (4) was also determined by single crystal X-ray diffraction. Complexes 3-7 are suitable precursors forming highly active catalysts in the transfer hydrogenation of a variety of simple ketones. Notably, the catalysts obtained by using the ruthenium complexes [Ru(Ph2PNHCH2-C4H3O)(eta(6)-p-cymene)Cl-2] (4) and [Ru(Ph2PNHCH2-C4H3O)(eta(6)-benzene)Cl-2] (5) are much more active in the transfer hydrogenation, converting the carbonyls to the corresponding alcohols in 97-99% yields (TOF <= 300 h(-1)), compared to analogous rhodium and iridium complexes and the trans-Ru(II)-p-cymene bis(phosphino)amine complex. (c) 2012 Elsevier Ltd. All rights reserved.