MCBÜ Açıkerişim Sistemi :: Browsing by Author "Demirhan F."

Browsing by Author "Demirhan F."

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Cyclopentadienylmolybdenum(VI) and molybdenum(V) oxo chemistry: New synthetic and structural features
(Wiley-VCH Verlag, 2002) Saurenz D.; Demirhan F.; Richard P.; Poli R.; Sitzmann H.
Convenient syntheses for Cp, Cp*, and related cyclopentadienyl derivatives (4Cp = C5HiPr4i CP‴ = C5H2tBU3-1,2,4) of formula [(Ring)2Mo2O5] are described. Compound [Cp2Mo2O5] was produced in good yields by the rapid oxidation of red [CpMoO2]4 with PhIO in CH2Cl2. [Cp*2Mo2O5] was obtained by CH3COOH acidification of aqueous solutions of [Cp*MoO3]-Na+, the latter being generated in a single step from [Cp*MoCl4] and more than 5 equiv. of aqueous NaOH in air. Minor quantities of [Cp*MoO2]2 were also isolated from this reaction, although the formation of this by-product may be reduced by using a two-step basic hydrolysis procedure. Extension of the latter strategy also allowed the preparation of [4Cp2Mo2O5], [Cp‴2Mo2O5], and [4CpMoO2Cl] in good yields, in addition to the by-product [Cp‴MoO2]2. X-ray structures are reported for compounds [4Cp2Mo2O5], [Cp‴2Mo2O5], [Cp*MoO2]2, [Cp‴MoO2]2, and [4CpMoO2Cl]. © Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
N-Heterocyclic carbene complexes of palladium(II) and rhodium(I) with pendant ferrocenylmethyl groups: Synthesis and electrochemistry
(Springer Netherlands, 2003) Demirhan F.; Yıldırım Ö.; Çetinkaya B.
1-Ferrocenylmethyl-3-benzylimidazolidinium iodide and 1-ferrocenylmethyl-3-(2,4,6-trimethylbenzyl)imidazolidinium iodide were prepared in good yields by boiling, under reflux, a solution of (ferrocenylmethyl)-trimethylammonium iodide and the appropriate N-alkyl-2-imidazoline in MeCN. From the 1-ferrocenylmethyl-3-ben- zylimidazolidinium iodide salt, N-heterocylic carbene complexes of Pd II and Rh I were synthesized by in situ deprotonation and subsequent trapping. The new compounds were characterized by C, H, N analyses, 1 H-n.m.r., 13 C-n.m.r. and by cyclic voltammetry. The n.m.r. properties of the complexes are compared with those of nonferrocenylated carbene derivatives. The c.v.'s of these compounds show a number of resolved redox processes, indicating that CH 2 Fc substituents are electronically isolated from the remaining molecular framework.
Reduction of [Cp2*Mo2O5] by thioglycolic acid in an aqueous medium: Synthesis and structure of [{Cp*Mo(μ-SCH2COO)}2(μ-S)]
(2006) Demirhan F.; Taban G.; Baya M.; Dinoi C.; Daran J.-C.; Poli R.
Compound [Cp2*Mo2O5] reacts with thioglycolic acid, HSCH2COOH, in an acidic (CF3COOH) mixed water-methanol solvent, to yield compound [{Cp*Mo(μ-SCH 2CO2)}2(μ-S)]. During this reaction, the thioglycolic acid acts as a reducing agent, as a ligand, and provides a sulfide ion for the Mo-S-Mo bridge. The molecular structure of the product can be described as containing two four-legged piano stools that share three legs. The Mo-Mo distance of 2.792(7) Å indicates metal-metal bonding, in agreement with the compound diamagnetism. © 2005 Elsevier B.V. All rights reserved.
Reduction of [Cp*2Mo2O5] in aqueous medium: Structure and properties of a triangular mixed oxo-hydroxo-bridged product, [Cp*3Mo3(μ-O)2(μ-OH) 4](X)2 (X = CF3CO2 or CF 3SO3)
(Wiley-VCH Verlag, 2006) Demirhan F.; Çaǧatay B.; Demir D.; Baya M.; Daran J.-C.; Poli R.
The reduction of [Cp*2Mo2O5] with Zn in a MeOH/H2O solution acidified with either CF3COOH or CF3SO3H leads to the formation of the [Cp* 3Mo3(μ-O)2(μ-OH)4] 2+ ion as its trifluoroacetate or trifluoromethanesulfonate salt. The structure of the compound was confirmed by X-ray analyses. The anions establish hydrogen-bonding interactions with all four bridging OH groups. Density functional calculations afford bonding parameters in close agreement with the observed structure and indicate that the cluster is best described as a valence-delocalized Mo313+ species. The five metal electrons are distributed among an α-type (z2) orbital, which accounts for most of the metal-metal attraction, and two essentially metal-metal nonbonding e-type (xy) orbitals with a slight Mo(μ-O) π*-type contribution. Because of the C2 symmetry, the latter orbitals are not degenerate. The calculations show that the unpaired electron is located in a molecular orbital with equal contribution from two Mo atoms, in agreement with the experimental observation of coupling of the unpaired electron to two Mo atoms in the isotropic EPR spectrum. © Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Improved syntheses of [Cp2* Mo2 O5] and [Cp2* W2 O5]: Structural characterization of Na[Cp*MoO3] · 5H2O and [Cp2* W2 O5]
(2007) Dinoi C.; Taban G.; Sözen P.; Demirhan F.; Daran J.-C.; Poli R.
Use of aqueous conditions and the ROOH (R = tBu or H) compounds as oxidizing agents affords a simple two-step, one-pot synthetic procedure leading to [Cp2* M2 O5] (M = Mo, W) from [M(CO)6] selectively and in high yields. The hexacarbonyl compounds are converted to Na[Cp*M(CO)3] in refluxing THF, then the mixture is diluted with water (W) or aqueous NaOH (Mo) and directly treated with 6 equiv. of ROOH. Acidification of an aqueous solution of the Na[Cp*MO3] product affords spectroscopically pure [Cp2* M2 O5] in high isolated yields (global yields from [M(CO)6], for R = tBu: Mo, 91%; W, 87%). The X-ray structures of Na[Cp*MoO3] · 5H2O and [Cp2* W2 O5] are also reported. © 2007 Elsevier B.V. All rights reserved.
Aqueous reduction of [Cp*2W2O5]: Characterization of the triangular clusters [Cp*3W 3O4(OH)2]2+ and [Cp* 3W3O6]+ - Comparison with molybdenum
(Wiley-VCH Verlag, 2007) Dinoi C.; Sözen P.; Taban G.; Demir D.; Demirhan F.; Prikhodchenko P.; Gun J.; Lev O.; Daran J.-C.; Poli R.
Zinc reduction of Cp*2W2O5 in an acidified water-methanol medium affords the green 3-electron trinuclear cluster [Cp*3W3O4(OH)2]2+, isolated and crystallographically characterized as the triflate salt, 1. Upon exposure to air, this complex is oxidized to a related 2-electron cluster, [Cp*3W3O6]+, which was crystallized and characterized in three different salts, 2-4. The 3-electron cluster exhibits a near-tetragonal frozen-glass EPR spectrum, and it shows evidence of coupling of the unpaired electron to only one of the three W atoms. The two-electron cluster is diamagnetic. An electrospray ionization MS n study revealed a stepwise expulsion of neutral [Cp*WO 2] units as the main fragmentation process. DFT calculations unveiled the intimate details of the electronic structures of these complexes and fully rationalized the structural and spectroscopic properties. © Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Synthesis and spectroscopic characterization of new [Cu( tBusalpphen)]2, [MoCl2(salpphen)]2 complexes and Sn2Cl8(tBusalpphen).2HNEt 3 adduct
(2007) Sözen P.; Akgül Y.; Demirhan F.
Tetradentate Schiff base ligands, which were derived from the condensation of phenylenediamine with salicylaldehyde [salpphenH2: N,N′-p-phenylene-bis(salicyclideneimine)] or 3,5-di-tert-butyl-2- hydroxybenzaldehyde [tBusalpphenH2: N, N′-p-phenylene-bis(3,5-di-tert-butylsalicylidene)] and their complexes of Cu(II), Mo(IV) and adduct of Sn(IV) were synthesized and characterized by 1H-NMR, 13C-NMR, and IR spectroscopic methods, mp, elemental analysis, and magnetic susceptibility. According to these data probable structures were assigned to these complexes and adduct. These are of the formula [Cu(tBusalpphen)]2 and [MoCl 2(salpphen)]2, an d Sn2Cl8( tBusalpphen).2HNEt3. [Cu(tBusalpphen)] 2 was prepared by the reactionof the metal salt with the tBusalpphenH2 Schiff base ligand in EtOH. [MoCl 2(salpphen)]2 was synthesized by reactions of [MoCl 4(CH3CN)2] with the salpphenH2 Schiff base ligand in THF. The Schiff base adduct Sn2Cl 8(tBusalpphen).2HNEt3 was synthesized by the reaction of SnCl4 with the tBuSalpphenH2 Schiff base ligand in the presence of NEt3 in toluene. © TÜBİTAK.
Reduction of [Cp2*Mo2O5] by mercaptopropionic acid in an aqueous medium. Isolation and characterization of a dinuclear oxo- and 3-sulfido-proprionato(2-)-bridged molybdenum(IV) compound
(2007) Dinoi C.; Prikhodchenko P.; Demirhan F.; Gun J.; Lev O.; Daran J.-C.; Poli R.
Reaction of Cp2*Mo2O5 with HSCH2CH2COOH in acidic (by CF3COOH) 50:50 MeOH-H2O solvent at room temperature yields compound Cp2*Mo2(μ-O)(μ-SCH2CH2CO2)2, a dinuclear diamagnetic MoIV compound with a two-leg-sharing bis(four-legged piano stool) structure and a Mo-Mo distance of 2.6833(6) Å. A reaction monitoring by ESI MS shows the formation of an intermediate 18 mass units heavier, interpreted as a dihydroxo analogue. Electrochemistry shows a reversible, pH independent oxidation process and an irreversible, pH-dependent reduction process. Contrary to a recently published analogous reaction with the closely related HSCH2COOH substrate, this process does not lead to C-S bond cleavage. © 2007 Elsevier B.V. All rights reserved.
Rational, facile synthesis and characterization of the neutral mixed-metal organometallic oxides Cp*2MoxW6-xO 17 (Cp* = C5Me5, x = 0, 2, 4, 6)
(Wiley-VCH Verlag, 2009) Taban-Çahskan G.; Agustin D.; Demirhan F.; Vendier L.; Poli R.
The reaction of the bis(pentamethylcyclopentadienyl)pentaoxidodimetal complexes Cp*2M2O5 with four equivalents of Na2M′O4 (M, M′ = Mo, W) in acidic aqueous medium constitutes a soft and selective entry into neutral Lindqvist-type organometallic mixed-metal oxides Cp*2MoxW 6-xO17 [x = 6 (1), 4 (2), 2 (3), 0 (4)]. The identity of the complexes is demonstrated by elemental analyses, thermogravimetric analyses and infrared spectroscopy. Thermal degradation of 1-4 up to above 500 °C leads to Mox/6W1-;x/6O3. The molecular identity and geometry of compound 2 is further confirmed by a fit of the powder X-ray diffraction pattern with a model obtained from, previously reported, single-crystal X-ray structures of 1 and 4, with which 2 is isomorphous. DFT calculations on models obtained by replacing Cp* with Cp (I-IV) validate the structural assignments and assist in the assignment of the M,M′-O vibrations. © Wiley-VCH Verlag GmbH & Co. KGaA.
Reaction of [Cp*2W2O5] with mercaptocarboxylic acids: Addition rather than reduction. Isolation and characterization of Cp*WO2(SCH2CH2COOH)
(2011) Sözen P.; Daran J.-C.; Manoury E.; Demirhan F.; Poli R.
The reaction of Cp*2W2O5 with HS(CH2)nCOOH (n = 1, 2) in MeOH or in CH 2Cl2 solutions at room temperature proceeds in slightly different ways depending on the value of n. For n = 2, it selectively yields compound Cp*WO2(SCH2CH2CO 2H), which has been isolated and characterized by elemental analysis, NMR and single crystal X-ray diffraction. The reaction is equilibrated, being shifted to the product by absorption of water by anhydrous Na2SO 4 in CH2Cl2, and to the reactants by addition of water. Contrary to the Mo analogue, no products resulting from metal reduction are obtained. The corresponding reaction for n = 1 occurs similarly at low substrate/W ratios (<0.5), but proceeds further to several uncharacterized products for greater substrate amounts. The primary product could not be isolated, but its 1H NMR spectrum suggests a different, asymmetric structure. © 2010 Elsevier B.V. All rights reserved.
1-Ferrocenylmethyl-3-(2,4,6-tri-methyl-benzyl)-1H-imidazolidin-3-ium iodide and trans-bis-(3-benzyl-1-ferrocenylmethyl-1H-imidazolidin-2-yl-idene) diiodidopalladium(II)
(2012) Daran J.-C.; Demirhan F.; Yldrm O.; Çetinkaya B.
Owing to increasing inter-est in the use of N-heterocyclic carbenes (NHCs) based on imidazolidinium ions as ligands in the design of highly efficient transition-metal-based homogeneous catalysts, the characterizations of the 1-ferrocenylmethyl-3-(2,4,6-trimethyl-benzyl)imidazolidin-3-ium iodide salt, [Fe(C 5H 5)(C 19H 24N 2)]I, (I), and the palladium complex trans-bis-(3-benzyl-1-ferrocenylmethyl-1H- imidazolidin-2-yl-idene)diiodidopalladium(II), [Fe 2Pd(C 5H 5) 2(C 16H 17N 2) 2I 2], (II), are re-ported. Compound (I) has two iodide anions and two imidazolidinium cations within the asymmetric unit (Z′ = 2). The two cations have distinctly different con-formations, with the ferrocene groups orientated exo and endo with respect to the N-heterocyclic carbene. Weak C-H donor hydrogen bonds to both the iodide anions and the π system of the mesitylene group combine to form two-dimensional layers perpendicular to the crystallographic c direction. Only one of the formally charged imidazolidinium rings forms a near-linear hydrogen bond with an iodide anion. Complex (II) shows square-planar coordination around the Pd II metal, which is located on an inversion centre (Z′ = 0.5). The ferrocene and benzyl substituents are in a trans-anti arrangement. The Pd-C bond distance between the N-heterocyclic carbene ligands and the metal atom is 2.036 (7) Å. A survey of related structures shows that the lengthening of the N-C bonds and the closure of the N-C-N angle seen here on metal complexation is typical of similar NHCs and their complexes. © 2012 International Union of Crystallography.
Rational synthesis and characterization of the mixed-metal organometallic polyoxometalates [Cp*Mo xW 6-xO 18] - (x = 0, 1, 5, 6)
(2012) Taban-Çşkan G.; Mesquita Fernandes D.; Daran J.-C.; Agustin D.; Demirhan F.; Poli R.
The reaction between the oxometallic complexes Cp* 2M 2O 5 and Na 2M′O 4 (M, M′ = Mo, W) in a 1:10 molar ratio in an acidic aqueous medium constitutes a mild and selective entry into the anionic Lindqvist-type hexametallic organometallic mixed oxides [Cp*Mo xW 6-xO 18] - [x = 6 (1), 5 (2), 1 (3), 0 (4)]. All of these compounds have been isolated as salts of nBu 4N + (a), nBu 4P + (b), and Ph 4P + (c) cations and two of them (1 and 3) also with the n-butylpyridinium (nBuPyr +, d) cation. The compounds have been characterized by elemental analyses, thermogravimetric analyses, electrospray mass spectrometry, and IR spectroscopy. The molecular identity and geometry of compounds 1c, 2a, and 2c have been confirmed by single-crystal X-ray diffraction. Density functional theory calculations on models obtained by replacing Cp* with Cp (I-IV) have provided information on the assignment of the terminal M=O and bridging M-O-M vibrations. © 2012 American Chemical Society.
Molybdenum versus tungsten for the epoxidation of cyclooctene catalyzed by [Cp*2M2O5]
(Wiley-VCH Verlag, 2013) Sözen-Aktaş P.; Manoury E.; Demirhan F.; Poli R.
The catalytic activity of [Cp*2M2O5] (M = Mo, W; Cp* = pentamethylcyclopentadienyl) for the homogeneous epoxidation of a solution of cyclooctene in MeCN/toluene follows the order Mo >> W when using tert-butyl hydroperoxide (TBHP)/decane as oxidant, in contrast to the inverse order (W >> Mo) when using aqueous H 2O2 as oxidant. The catalytic activity for the Mo system strongly depends on the solvent used to deliver the oxidant (TBHP/decane >> TBHP/H2O). The low activity of the W system is also decreased when using TBHP/water in place of TBHP/decane. For both metals, H 2O2/H2O is a better oxidant than TBHP/H 2O. However, whereas the Mo-based catalyst is much more active for the TBHP/decane epoxidation in spite of the lower TBHP oxidizing power (TBHP/decane > H2O2/H2O > TBHP/H 2O), the W-based system is much more active for the H 2O2/H2O epoxidation in spite of the negative effect of water (H2O2/H2O > TBHP/decane > TBHP/H2O). The kinetic profile of the TBHP/decane epoxidation process is affected by product inhibition. Initial rate measurements show that the rate law is first order with respect to substrate and has saturation behavior with respect to the oxidant. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Speciation of [Cp*2M2O5] in polar and donor solvents
(2013) Sözen-Aktaş P.; Del Rosal I.; Manoury E.; Demirhan F.; Lledõs A.; Poli R.
The speciation of compounds [Cp*2M2O 5] (M=Mo, W; Cp*=pentamethylcyclopentadienyl) in different protic and aprotic polar solvents (methanol, dimethyl sulfoxide, acetone, acetonitrile), in the presence of variable amounts of water or acid/base, has been investigated by 1H NMR spectrometry and electrical conductivity. Specific hypotheses suggested by the experimental results have been further probed by DFT calculations. The solvent (S)-assisted ionic dissociation to generate [Cp*MO2(S)]+ and [Cp*MO 3]- takes place extensively for both metals only in water/methanol mixtures. Equilibrium amounts of the neutral hydroxido species [Cp*MO2(OH)] are generated in the presence of water, with the relative amount increasing in the order MeCN≈acetone
Investigation of the reaction of [Cp*2M2O 5] (M = Mo, W) with hydrogen peroxide and tert-butylhydroperoxide in MeCN; Implications for olefin epoxidation catalyzed by organomolybdenum and organotungsten compounds Dedicated to Maria-José Calhorda on the occasion of her 65th birthday.
(Elsevier B.V., 2014) Bhaumik C.; Manoury E.; Daran J.-C.; Sözen-Aktaş P.; Demirhan F.; Poli R.
Compounds [Cp*2M2O5] (M = Mo, W) react with stoichiometric amounts of H2O2 (as a 30% w/w solution in water) and tBuOOH (TBHP, as a 70% w/w solution in decane) in MeCN solution to yield a variety of products as shown by the 1H NMR monitoring of the Cp* resonance. The reaction rate increases in the order W < Mo and TBHP < H2O2. While the total Cp* intensity remains constant when using stoichiometric amounts of oxidant, use of excess oxidant results in the ultimate total Cp* loss. From the decomposed solutions, crystals of [Cp*2Mo 6O17] (1), (C5Me5O)[Cp*M 6O18] (M = Mo, 2a; W, 2b), and (C5Me 5O)2[Mo6O19] (3) were recovered and analyzed by X-ray diffraction. Catalytic cyclooctene epoxidation experiments with (nBu4N)2[M6O19] (M = Mo, W) in a 3:1 MeCN/toluene mixture at 55 °C using either aqueous H 2O2 or TBHP/decane as oxidant revealed that these are not the active forms of the catalyst which is generated under the same conditions from [Cp*2M2O5], as reported in previous contributions from our group (Chem. Eur. J., 2010, 16, 9572-9584; Eur. J. Inorg. Chem., 2013, 2728-2735). Further catalytic studies using aged [Cp*2Mo2O5]/TBHP and [Cp* 2W2O5]/H2O2 solutions show a small loss of activity (<50% in one week) attesting the robustness of the non-organometallic catalytically active species that is generated from the decomposition of [Cp*2M2O5]. These results cast doubts on the role of cyclopentadienyl as a supporting ligand for stable olefin epoxidation catalysts. © 2013 Elsevier B.V. All rights reserved.
Synthesis, structure, electrochemical and antimicrobial properties of N,N′-bis(ferrocenylmethyl)imidazolinium salts
(Elsevier S.A., 2014) Özbek H.A.; Aktaş P.S.; Daran J.-C.; Oskay M.; Demirhan F.; Çetinkaya B.
The N,N′-bis(ferrocenylmethyl)imidazolinium chloride (3) and bromide (4) were prepared by reaction of N,N'-bis(ferrocenylmethyl)ethylenediamine (2) with NH4X (X = Cl, Br). The N,N′-bis(ferrocenylmethyl)imidazolinium tetrafluoroborate (6) was obtained in two steps from compound (2). The first step involves the synthesis of N,N′-bis(ferrocenylmethyl)imidazolidine (5) by condensation of (2) with aqueous formaldehyde. Compound (5) was successfully converted to the N,N′-bis(ferrocenylmethyl)imidazolinium tetrafluoroborate (6) by treatment with tritylium tetrafluoroborate. The new compounds were characterized by 1H and 13C NMR, IR and elemental analysis techniques which support the proposed structures. The X-ray crystal structure of the N,N′-bis(ferrocenylmethyl)imidazolidine (5) shows two ferrocenyl moieties bridged by an imidazolidine ring. The electrochemical properties were determined by cyclic voltammetry for all compounds. The compounds were screened for their in vitro antimicrobial activities against the Gram-positive, Gram-negative bacteria and antifungal activity against a Candida albicans. (3), (4), (6) show significant antimicrobial activity and theirs MIC values ranged from 169 to 520 μg/mL. © 2014 Elsevier B.V. All rights reserved.
Synthesis, structure, and electrochemical properties of N,Nʹ-bis(ferrocenylmethylene)ethylenediamine Schiff base and its metal complexes
(Taylor and Francis Inc., 2017) Akcan Kardaş T.; Avcı Özbek H.; Akgül Y.; Demirhan F.
The reaction of N,N'-bis(ferrocenylmethylene)ethylenediamine (FcNN) Schiff base with metal salts gave SnCl4FcNN (1), SnCl2FcNN(H2O)2 (2), Sn2(CH3)4Cl4FcNN (3), Ti2Cl8FcNN (4), CdFcNN(NO3)2 (5), and CuFcNN(NO3)2 (6). New complexes (1)–(6) were characterized by IR and elemental analysis techniques. IR spectra showed that the Schiff base was coordinated to the metal ions in a bidentate manner with N,N' donor sites. The 1H NMR spectra of complexes (1), (2), and (4) show all the expected signals with a typical signal pattern of disubstituted ferrocenyl groups. The electrochemical properties of complexes were determined by cyclic voltammetry. Cyclic voltammetry results show that these complexes exhibit one irreversible oxidation peak. © 2017 Taylor & Francis Group, LLC.
Synthesis, structure, and antimicrobial properties of mixed-metal organometallic polyoxometalates [Cp*2M5VO17]− (M = Mo, W)
(Taylor and Francis Ltd., 2021) Avcı Özbek H.; Erden Kopar E.; Demirhan F.
A series of Lindqvist-type polyoxometalate (POM) compounds [Cat][Cp*2M5VO17] (M = Mo (1), W (2)) were obtained from Cp*2M2O5 and NaVO3 in a 1:10 molar ratio in an acidic aqueous-methanol medium ([Cat]: Bu4P+ (1a, 2a), Bu4N+ (1b, 2b), Ph4P+ (1c, 2c), and BuNC5H5+ (1d, 2d)). They have been structurally characterized by 1H and 31P NMR, FT-IR, TGA, ESI, and elemental analysis techniques which support the proposed structures. In antibacterial studies, Ph4P[Cp*2Mo5VO17] (1c) is the compound that shows the highest antimicrobial activity against both gram-positive and gram-negativebacteria. © 2021 Informa UK Limited, trading as Taylor & Francis Group.
Epoxidation of Cis-cyclooctene with Hydrogen Peroxide Catalyzed by Lindqvist Type Polyoxometalates
(John Wiley and Sons Inc, 2023) Avcı Özbek H.; Demirhan F.
In our study, a method for the epoxidation of cis-cyclooctene was researched using a series of Lindqvist type POMs Cp*2MoxW6−xO17 (x=0, 2, 4, 6) and [Cp*MoxW6−xO18]− (x=0, 1, 5, 6) as a catalyst in the presence of 30 % H2O2 as a green oxidant. This catalytic system containing polyoxometalates and H2O2 has applied the most succesful system in obtaining epoxide product with excellent yields for cis-cyclooctene in acetonitrile at 55 °C. Maximum epoxidation efficiency of 99 % was observed under optimized conditions for Ph4P[Cp*MoW5O18] (2c). © 2023 Wiley-VCH GmbH.
Heck coupling reactions of aryl halides catalyzed by saturated ferrocenylmethylimidazolinium salts/palladium
(Springer Science and Business Media Deutschland GmbH, 2023) Musaoğlu D.; Avcı Özbek H.; Demirhan F.
In situ prepared Pd(OAc)2/N,N′-bis(ferrocenyl methyl) imidazolinium salt catalyst systems were successfully applied to Heck reactions of various aryl halides (bromides, iodides) with olefins (styrene, ethyl acrylate). Catalytic studies showed that N,N′-bis(ferrocenylmethyl)imidazolinium chloride containing a saturated imidazole ring as an auxiliary catalyst in the presence of Pd(OAc)2 was highly efficient in Heck coupling reaction of aryl halides in DMF. © 2022, Iranian Chemical Society.

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