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Öğe Kiral Fosfinit Ligandları Içeren Yeni Rutenyum(II) Komplekslerinin Sentezi ve Ketonların Asimetrik Transfer Hidrojenasyon Reaksiyonundaki Katalitik Aktivitelerinin Arastırılması(2015) Kayan, Cezmi; Gürbüz, Nevin; Karakaplan, Mehmet; Aydemir, MuratEtkin kiral fosfor ligandların özellikle kiral iskelet yapısına sahip olanların geliştirilmesine yönelik çalışmalar asimetrik katalizin en öncelikli konuları arasında yeralmaktadır. Gu?nu?mu?ze kadar, fosfin ve metal-fosfin komplekslerinin sentezine yönelik çok çaba harcanmış olmasına rağmen, benzer yapıdaki bis(fosfinitler) yeterince araştırılmamıştır. Fosfin ligandları metal katalizli asimetrik dönu?şu?mlerde oldukça yaygın uygulama alanları bulmuştur. Ancak, fosfinitler fosfinlerle kıyaslandığında farklı kimyasal, elektronik ve yapısal özelliklere sahip olmaları bu ligandları daha da ilgi çekici kılmaktadır. Örneğin, fosfinitlerdeki metal fosfor bağı fosfinlerdeki bağ ile kıyaslandığında, elektron çekici P-OR grubundan dolayı daha gu?çlu?du?r. Ayrıca, fosfinitlerdeki P(OR)R2 boş ?* orbitalinin varlığı, fosfiniti daha iyi bir alıcı konumuna getirerek kararlı duruma getirebilmektedir. Ancak, fosfinitlerin analogları olan fosfinlere göre en bu?yu?k avantajı hazırlanmalarındaki kolaylıktır. İlgili ketonların indirgenmesi sonucu elde edilen kiral sekonder alkoller, ticari açıdan önemli birçok farmasötikler, zirai maddeler, parfu?mler, tatlandırıcılar ve özel materyaller için anahtar konumundaki madde görevi u?stlenir. Asimetrik sentez genellikle çok bu?yu?k miktarlarda nispeten du?şu?k maliyetli kiral u?ru?nler sağlama avantajı nedeniyle en çok dikkat çeken yöntem olarak kabul edilir. Ketonların ilgili kiral alkollere asimetrik dönu?şu?mu? için kullanılan en bilinen yöntemler hidrosililasyon, hidroborasyon, biyoindirgeme ve katalitik (transfer) hidrojenasyon olarak sayılabilir. Bu yöntemde karbonil bileşiklerini ilgili alkollere dönu?ştu?rmek için hidrojen kaynağı olarak sekonder alkoller (2- propanol v.b.) kullanılır. Böylece, moleku?ler hidrojen kullanılması nedeniyle ortaya çıkabilecek patlama riski ortadan kaldırılır. Üstelik bu reaksiyonda kullanılan 2-propanol’ u?n oldukça kararlı, çalışılması kolay, anti-toksik ve ucuz olması da metodun diğer avantajlarındandır. Bu projede; ilk olarak birbirinden farklı kiral bileşiklerden yola çıkılarak regioseçici epoksit halka açılması yöntemiyle kiral amino alkoller hazırlanmıştır. Sonraki basamakta ise kiral aminoalkoller PPh2Cl etkileştirilerek kiral fosfinit tu?revleri sentezlenmiştir. Hazırlanan yeni kiral fosfinit bileşikleri Ru[(?6-p-simen)Cl2]2 ve Ru[(?6-benzen)Cl2]2 ile etkileştirilerek yeni Ru(II) geçiş metal kompleksleri sentezlenmiş ve bu komplekslerin yapıları NMR, IR, LC- ESI-IT-TOF MS ve element analizi ile aydınlatılmıştır. Son olarak elde edilen komplekslerin, ketonların asimetrik transfer hidrojenasyon reaksiyonlarında kiral katalizör olarak kullanımları araştırılmıştır.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, MuratA 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.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, MuratMetal-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.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, ErtanThe 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.Öğe Synthesis and characterization of ether-derivatized aminophosphines and their application in C-C coupling reactions(Elsevier Science Sa, 2010) Biricik, Nermin; Kayan, Cezmi; Gumgum, Bahattin; Fei, Zhaofu; Scopelliti, Rosario; Dyson, Paul J.; Gurbuz, NevinFour new bis(phosphino) amine ligands (Ph2P)(2)N-C6H3-R, where R = 3,5-OMe (1), 2,5-OMe (2), 2,4-OMe (3) or 3,4-OMe (4), were prepared via aminolysis of the corresponding dimethoxyanilines with 2 equiv. of diphenylphosphine chloride in the presence of triethyl amine. Oxidation of these ligands with aqueous H2O2, elemental S-8 or Se powder afforded the corresponding chalcogen oxides 1a-4a, sulfides 1b-4b and selenides 1c-4c in good yields. Reaction of 1-4 with [MCl2(cod)] (M = Pt, Pd; cod = cycloocta-1,5-diene) in equimolar ratios afforded cis-[MCl2{(Ph2P)(2)N-C6H3-R}] (M = Pt; R = 3,5-OMe 1d, R = 2,5-OMe 2d, R = 2,4-OMe 3d, and R = 3,4-OMe 4d. M = Pd; R = 3,5-OMe 1e, R = 2,5-OMe 2e, R = 2,4-OMe 3e, and R = 3,4-OMe 4e). Similarly, reaction of [Cu(CH3CN)(4)]PF6 with the 1-4 in 1:2 ratio gave [Cu{(Ph2P)(2)N-C6H3-R}(2)]PF6 (R = 3,5-OMe 1f, 2,5-OMe 2f, 2,4-OMe 3f and 3,4-OMe 4f). All new compounds were fully characterized by spectroscopy and elemental analysis and the molecular structures of seven representative compounds were determined by single-crystal X-ray crystallography. In addition, the palladium complexes were investigated as pre-catalysts in C-C coupling reactions. (C) 2009 Elsevier B.V. All rights reserved.Öğe Synthesis of new aminophosphine complexes and their catalytic activities in C-C coupling reactions(Elsevier Science Sa, 2008) Biricik, Nermin; Durap, Feyyaz; Kayan, Cezmi; Gumguma, Bahattin; Gurbuz, Nevin; Ozdemir, Ismail; Ang, Wee HanTwo new aminophosphines, benzyl-N(Ph2P)(2) and 2-picolyl-N(Ph2P)(2), have been synthesized. Oxidation of the aminophosphines with either hydrogen peroxide, elemental sulfur and selenium gave the corresponding oxides, sulfides and selenides benzyl-N(Ph2P=E)(2) and 2-picolyl-N(Ph2P=E)(2), where E = O, S, or Se. Complexes [benzyl-N(Ph2P)(2)]MCl2 and [2-picolyl-N(Ph2P)(2)]MCl2, where M = Pd, Pt, were obtained by the reaction of the aminophosphines with MCl2(cod). The new compounds were characterised by NMR, IR spectroscopy and microanalysis. Furthermore, representative solid-state structures of the palladium and platinum complexes were determined using single crystal X-ray diffraction analysis. The palladium complexes were further investigated as potential catalysts in C-C coupling reactions. (c) 2008 Elsevier B. V. All rights reserved.Öğe Transfer hydrogenation of ketones catalyzed by new rhodium and iridium complexes of aminophosphine containing cyclohexyl moiety and photosensing behaviors of rhodium and iridium based devices(Elsevier Science Sa, 2014) Rafikova, Khadichakhan; Kystaubayeva, Nurzhamal; Aydemir, Murat; Kayan, Cezmi; Ocak, Yusuf Selim; Temel, Hamdi; Zazybin, AlexeyThe reaction of [Rh(mu-Cl)(cod)](2) and Ir(eta(5)-C5Me5)(mu-Cl)Cl](2) with aminophosphine ligands Cy2PNHCH2-C4H3X (X: O; S) gave a range of new monodendate [Rh(Cy(2)PNHCH(2)eC(4)H(3)O)(cod) Cl], (1), [Rh(Cy(2)PNHCH(2)eC(4)H3S)(cod) Cl], (2), [Ir(Cy2PNHCH2-C4H3O)(h(5)-C5Me5)Cl-2], (3) and [Ir(Cy2PNHCH2 -C4H3S)(eta(5)-C5Me5)Cl-2], (4) complexes, which were characterized by analytical and spectroscopic methods. The new rhodium(I) and iridium(III) catalysts were applied to transfer hydrogenation of acetophenone derivatives using 2-propanol as a hydrogen source. The results showed that the corresponding alcohols could be obtained with high activity (up to 99%) under mild conditions. Notably, [Rh(Cy2PNHCH2-C4H3O)(cod)Cl] complex (1) is much more active than the other analogous complexes in the transfer hydrogenation. Moreover, organiceinorganic rectifying contacts were fabricated forming rhodium(I) and iridium(III) complex thin films on n-Si semiconductors and evaporating Au metal on the structures. Electrical properties of the contacts including ideality factor, barrier height and series resistance were determined using their currentevoltage (IeV) data. The photoelectrical characteristics of the devices were examined under the light with 40-100 mW/cm(2) illumination conditions. It was seen that light had strong effects on IeV characteristics of the devices and the ones fabricated using 3 and 4 complexes had unusually forward and reverse bias photoconducting behavior. (C) 2014 Elsevier B.V. All rights reserved.
