- Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
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The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
- Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 14365 - 14373
(2019/09/06)
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- Site-Selective, Remote sp3 C?H Carboxylation Enabled by the Merger of Photoredox and Nickel Catalysis
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A photoinduced carboxylation of alkyl halides with CO2 at remote sp3 C?H sites enabled by the merger of photoredox and Ni catalysis is described. This protocol features a predictable reactivity and site selectivity that can be modulated by the ligand backbone. Preliminary studies reinforce a rationale based on a dynamic displacement of the catalyst throughout the alkyl side chain.
- Sahoo, Basudev,Bellotti, Peter,Juliá-Hernández, Francisco,Meng, Qing-Yuan,Crespi, Stefano,K?nig, Burkhard,Martin, Ruben
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supporting information
p. 9001 - 9005
(2019/06/24)
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- Mild C-H functionalization of alkanes catalyzed by bioinspired copper(ii) cores
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Three new copper(ii) coordination compounds formulated as [Cu(H1.5bdea)2](hba)·2H2O (1), [Cu2(μ-Hbdea)2(aca)2]·4H2O (2), and [Cu2(μ-Hbdea)2(μ-bdca)]n (3) were generated by aqueous medium self-assembly synthesis from Cu(NO3)2, N-butyldiethanolamine (H2bdea) as a main N,O-chelating building block and different carboxylic acids [4-hydroxybenzoic (Hhba), 9-anthracenecarboxylic (Haca), or 4,4′-biphenyldicarboxylic (H2bdca) acid] as supporting carboxylate ligands. The structures of products range from discrete mono- (1) or dicopper(ii) (2) cores to a 1D coordination polymer (3), and widen a family of copper(ii) coordination compounds derived from H2bdea. The obtained compounds were applied as bioinspired homogeneous catalysts for the mild C-H functionalization of saturated hydrocarbons (cyclic and linear C5-C8 alkanes). Two model catalytic reactions were explored, namely the oxidation of hydrocarbons with H2O2 to a mixture of alcohols and ketones, and the carboxylation of alkanes with CO/S2O82- to carboxylic acids. Both processes proceed under mild conditions with a high efficiency and the effects of different parameters (e.g., reaction time and presence of acid promoter, amount of catalyst and solvent composition, substrate scope and selectivity features) were studied and discussed in detail. In particular, an interesting promoting effect of water was unveiled in the oxidation of cyclohexane that is especially remarkable in the reaction catalyzed by 3, thus allowing a potential use of diluted, in situ generated solutions of hydrogen peroxide. Moreover, the obtained values of product yields (up to 41% based on alkane substrate) are very high when dealing with the C-H functionalization of saturated hydrocarbons and the mild conditions of these catalytic reactions (50-60 °C, H2O/CH3CN medium). This study thus contributes to an important field of alkane functionalization and provides a notable example of new Cu-based catalytic systems that can be easily generated by self-assembly from simple and low-cost chemicals.
- Kirillova, Marina V.,Fernandes, Tiago A.,André, Vania,Kirillov, Alexander M.
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supporting information
p. 7706 - 7714
(2019/08/30)
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- Regioselectivity inversion tuned by iron(iii) salts in palladium-catalyzed carbonylations
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Impactful regioselectivity control is crucial for cost-effective chemical synthesis. By using cheap and abundant iron(iii) salts, the hydroxycarbonylations of both aromatic and aliphatic alkenes were significantly enhanced in both reactivity and selectivity (iso/n or n/iso up to >99:1). Moreover, Pd-catalyzed carbonylation selectivity can be switched from branched to linear by using different Fe(iii) salts. In addition, similar results were obtained for the carbonylation of secondary alcohols.
- Huang, Zijun,Cheng, Yazhe,Chen, Xipeng,Wang, Hui-Fang,Du, Chen-Xia,Li, Yuehui
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supporting information
p. 3967 - 3970
(2018/04/23)
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- CATALYTIC CARBOXYLATION OF ACTIVATED ALKANES AND/OR OLEFINS
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The present invention relates to a method of reacting starting materials with an activating group, namely alkanes carrying a leaving group and/or olefins, with carbon dioxide under transition metal catalysis to give carboxyl group-containing products. It is a special feature of the method of the present invention that the carboxylation predominantly takes place at a preferred position of the molecule irrespective of the position of the activating group. The carboxylation position is either an aliphatic terminus of the molecule or it is a carbon atom adjacent to a carbon carrying an electron withdrawing group. The course of the reaction can be controlled by appropriately choosing the reaction conditions to yield the desired regioisomer.
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Page/Page column 64; 72; 73
(2018/02/28)
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- Three-component 1D and 2D metal phosphonates: structural variability, topological analysis and catalytic hydrocarboxylation of alkanes
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Herein, we report the use of diphosphonate building blocks and chelating auxiliary N,N-ligands to generate novel polymeric architectures. Specifically, we report new 1D and 2D coordination polymers incorporating three components: transition metal ions (Co2+, Cu2+, Mn2+ or Zn2+), diphosphonate ligands (methane-diphosphonate, MDPA, or 1,2-ethanediphosphonate, EDPA) and N,N-heterocyclic chelators (1,10-phenanthroline, phen, or 2,2′-bipyridine, bpy). Six compounds were isolated under mild synthesis (ambient temperature) conditions: [Cu2(phen)2(EDPA)2(H2O)4]∞ (1), [Co(phen)(EDPA)(H2O)2]∞ (1a), {[Cu(phen)(MDPA)]·H2O]}∞ (2), [Mn(bpy)(EDPA)(H2O)2]∞ (3), [Zn(bpy)(EDPA)]∞ (4), and, lastly, a discrete Ni2+ molecular derivative [Ni(phen)(H2O)4](EDPA) (5). Synthetic details, crystal structures, and intermolecular interactions (π-π stacking and hydrogen bonding) in 1-5 are discussed. Topological analyses and classification of the underlying metal-organic networks in 1-4 were performed, revealing the uninodal 1D chains with the 2C1 topology in 1-3 and the binodal 2D layers with the 3,4L13 topology in 4. In 1-3 and 5, multiple hydrogen bonds lead to the extension of the structures to give 3D H-bonded nets with the seh-4,6-C2/c topology in 1 and 3, 2D H-bonded layers with the 3,5L52 topology in 2, and a 3D H-bonded net with the 6,6T1 topology in 5. The catalytic activity of compounds 1 and 1a was evaluated in a single-step hydrocarboxylation of cyclic and linear C5-C8 alkanes to furnish the carboxylic acids with one more carbon atom. These reactions proceed in the presence of CO, K2S2O8, and H2O at 60 °C in MeCN/H2O medium. Compound 1 showed higher activity than 1a and was studied in detail. Substrate scope was investigated, revealing that cyclohexane and n-pentane are the most reactive among the cyclic and linear C5-C8 alkanes, and resulting in the total yields of carboxylic acids (based on substrate) of up to 43 and 36%, respectively. In the case of cycloalkane substrates, only one cycloalkanecarboxylic acid is produced, whereas a series of isomeric monocarboxylic acids is generated when using linear alkanes; an increased regioselectivity at the C(2) position of the hydrocarbon chain was also observed.
- Demadis, Konstantinos D.,Anagnostou, Zafeiria,Panera, Aggeliki,Mezei, Gellert,Kirillova, Marina V.,Kirillov, Alexander M.
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p. 17788 - 17799
(2017/03/30)
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- Removing the Active-Site Flap in LipaseA from Candida antarctica Produces a Functional Enzyme without Interfacial Activation
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A mobile region is proposed to be a flap that covers the active site of Candida antarctica lipaseA. Removal of the mobile region retains the functional properties of the enzyme. Interestingly interfacial activation, required for the wild-type enzyme, was not observed for the truncated variant, although stability, activity, and stereoselectivity were very similar for the wild-type and variant enzymes. The variant followed classical Michaelis-Menten kinetics, unlike the wild type. Both gave the same relative specificity in the transacylation of a primary and a secondary alcohol in organic solvent. Furthermore, both showed the same enantioselectivity in transacylation of alcohols and the hydrolysis of alcohol esters, as well as in the hydrolysis of esters chiral at the acid part.
- Wikmark, Ylva,Engelmarkcassimjee, Karim,Lihammar, Richard,B?ckvall, Jan-E.
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p. 141 - 145
(2016/01/26)
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- Structurally well-characterized new multinuclear Cu(II) and Zn(II) clusters: X-ray crystallography, theoretical studies, and applications in catalysis
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Two new trinuclear Cu(ii) and dinuclear Zn(ii) clusters are crystallized out by reacting the metal salts with the triethanolamine (H3tea) ligand in the presence of benzoic acid (Hba). The complexes are characterized by elemental, thermal, magnetic, spectral (FTIR, UV-Visible, EPR, and photoluminescence) and single crystal X-ray studies. Single crystal X-ray crystallography reveals the composition of the complexes to be [Cu3(H2tea)2(ba)2(NO3)2] (1) and [Zn2(H2tea)(ba)3]H2O (2). FTIR ascertains the binding modes of H2tea-, ba- and NO3-. Triethanolamine binds in both the complexes in the monoanionic (H2tea-) mode. ba- is present as an anchoring auxiliary to generate di- and trinuclear clusters. The Cu(ii) ion is present as a distorted octahedral center in the Cu3 cluster (1), while the two Zn(ii) ions in 2 have been reported for the first time to possess distorted octahedral as well as tetrahedral geometry in the same molecule. The intriguing features of the non-covalent supramolecular interactions have been investigated and supported theoretically by using Hirshfeld surface analysis and ab initio methods. The solid state photoluminescence (PL) spectra of 1 and 2 disclose the luminescence property of the complexes. Due to the closed or nearly closed shell configuration (d9 or d10), the present complexes are screened for catalytic properties in the hydrocarboxylation of alkanes and cycloalkanes. The catalytic activity data are indicative of the potential catalytic properties of 1 and 2.
- Ansari, Istikhar A.,Sama, Farasha,Raizada, Mukul,Shahid,Ahmad, Musheer,Siddiqi, Zafar A.
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supporting information
p. 9840 - 9852
(2016/11/11)
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- How to force a classical chelating ligand to a metal non-chelating bridge: The observation of a rare coordination mode of diethanolamine in the 1D complex {[Cu2(Piv)4(H3tBuDea)](Piv)}n
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The novel chain coordination polymer {[Cu2(Piv) 4(H3tBuDea)](Piv)}n (1) has been prepared through the self-assembly reaction of copper(ii) nitrate with pivalic acid (HPiv) and N-tert-butyldiethanolamine (H2tBuDea) in acetonitrile solution. Crystallographic analysis revealed the extremely rare non-chelating bridging coordination mode of diethanolamine ligand in 1, observed for the first time in transition metal complexes, as well as in complexes of diethanolamine having a non-coordinating aliphatic group at the N atom. Possible reasons for such a coordination and analysis of the main coordination modes of diethanolamine-based ligands are discussed. Variableerature (1.8-300 K) magnetic susceptibility measurements showed that 1 represents a rare example of dicopper(ii) tetracarboxylate that is a diamagnetic solid at room temperature. This behaviour is compared with literature examples and discussed on the basis of DFT calculations. Furthermore, 1 acts as an efficient catalyst for the mild hydrocarboxylation of linear and cyclic C5-C8 alkanes into the corresponding carboxylic acids.
- Nesterova, Oksana V.,Kirillova, Marina V.,Guedes Da Silva, M. Fatima C.,Boca, Roman,Pombeiro, Armando J. L.
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p. 775 - 783
(2014/01/17)
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- Tautomeric effect of hydrazone Schiff bases in tetranuclear Cu(ii) complexes: Magnetism and catalytic activity towards mild hydrocarboxylation of alkanes
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Three new tetranuclear copper(ii) complexes [Cu(HL1)] 4·4EtOH (1·4EtOH), [Cu(HL2)]4 (2) and [Cu(H2L3)]4(NO3) 4·2H2O (3·2H2O) have been synthesized using three different hydrazone Schiff base ligands derived from the condensation of the aromatic acid hydrazides 2-hydroxybenzo-, 2-aminobenzo- or benzo-hydrazide, with 2,3-dihydroxybenzaldehyde. Complexes 1 and 3 have been characterized by single crystal X-ray diffraction analysis. The coordinating behaviour of the ligand depends on the nature of the ortho substituent present in the hydrazide moiety. The ligands bearing a strong electron donating group (by resonance) in the ortho position undergo complexation via enolization and deprotonation, whereas the absence of such an effect leads to complexation via the keto form, and two different types of tetranuclear Cu(ii) clusters, viz. open-cubane and cubane, are obtained. Variable temperature magnetic susceptibility measurements of complexes 1 and 3 have been carried out to examine the nature of magnetic interaction between the Cu(ii) centres. All the three complexes (1-3) act as good catalyst precursors towards mild hydrocarboxylation of linear and cyclic alkanes into carboxylic acids in water-acetonitrile medium.
- Sutradhar, Manas,Kirillova, Marina V.,Guedes Da Silva, M. Fatima C.,Liu, Cai-Ming,Pombeiro, Armando J. L.
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p. 16578 - 16587
(2013/12/04)
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- Topologically unique 2D heterometallic CuII/Mg coordination polymer: Synthesis, structural features, and catalytic use in alkane hydrocarboxylation
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The new two-dimensional (2D) heterometallic CuII/Mg coordination polymer [Cu2Mg2(μ-Htea)2(μ6- pma)(H2O)6]n?6nH2O (1) with an unprecedented [Cu2Mg(μ-O)2(μ-COO)2] - core has been easily generated by aqueous medium self-assembly from copper(II) nitrate, triethanolamine (H3tea), magnesium hydroxide, and pyromellitic acid (H4pma). The crystal structure of 1 is composed of infinite interdigitated 2D metal-organic layers that extend via H-bonds into an intricate 3D supramolecular framework. The topological analysis of 1 discloses a binodal 2,4-connected underlying 2D net with the unique topology described by the point symbol of (64?8?10)(6), further simplification of which leads to an uninodal 4-connected net with the sql topology. Apart from representing a very rare example of the heterometallic Cu/Mg coordination network, compound 1 also acts as an efficient catalyst precursor for the mild single-pot hydrocarboxylation of linear and cyclic C n (n = 5-9) alkanes into the corresponding Cn+1 carboxylic acids.
- Kirillov, Alexander M.,Karabach, Yauhen Y.,Kirillova, Marina V.,Haukka, Matti,Pombeiro, Armando J. L.
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scheme or table
p. 1069 - 1074
(2012/06/18)
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- New diamondoid-like [Cu3B(μ-O)6] core self-assembled from Bis-Tris biobuffer for mild hydrocarboxylation of alkanes to carboxylic acids
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The new tricopper(ii) complex [Cu3(μ3-BO)(H 3L)3][BF4]·2H2O (1) with an unprecedented diamondoid-like [Cu3B(μ-O)6] core has been easily generated by self-assembly in an aqueous medium from Cu(NO 3)2, NaBF4, NaOH and Bis-Tris (H5L) biobuffer, (HOCH2)3CN(CH2CH2OH) 2. Compound 1 efficiently promotes the mild single-pot hydrocarboxylation, by CO and H2O, of various linear and cyclic Cn (n = 2-8) alkanes into the corresponding Cn+1 carboxylic acids.
- Kirillov, Alexander M.,Karabach, Yauhen Y.,Kirillova, Marina V.,Haukka, Matti,Pombeiro, Armando J. L.
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supporting information; experimental part
p. 6378 - 6381
(2011/08/06)
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- Mild oxidative functionalization of alkanes and alcohols catalyzed by new mono- and dicopper(II) aminopolyalcoholates
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The new mono- and dicopper(II) complexes [Cu(H3L 1)(NCS)] (1) and [Cu2(μ-HL2) 2(NCS)2] (2) were easily self-assembled from Cu(CH 3COO)2·H2O, NaNCS, NaOH and N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine (H 4L1) or N-ethyldiethanolamine (H2L 2), respectively. They were fully characterized by IR spectroscopy, ESI-MS(±), elemental and single-crystal X-ray diffraction analyses, and applied as homogeneous catalysts for (i) the oxidation of alkanes by t-BuOOH in air to alkyl peroxides, alcohols and ketones, and in turn the oxidation of alcohols to ketones, and (ii) the single-pot aqueous medium hydrocarboxylation, by CO, H2O and K2S2O8, of various linear and cyclic Cn (n = 5-8) alkanes into the corresponding C n+1 carboxylic acids. Compound 1 was significantly more active in the oxygenation of alkanes and oxidation of alcohols, allowing to achieve 18% yield (TON = 800) of oxygenates in the oxidation of cyclohexane, and 78% yield (TON = 780) of cyclohexanone in the oxidation of cyclohexanol. In alkane hydrocarboxylations, 1 and 2 exhibited comparable activities with the total yields (based on alkane) of carboxylic acids attaining 39%. The selectivity parameters for oxidative transformations were measured and discussed, supporting free-radical mechanisms.
- Kirillov, Alexander M.,Kirillova, Marina V.,Shul'Pina, Lidia S.,Figiel, Pawe? J.,Gruenwald, Katrin R.,Guedes Da Silva, M. Fátima C.,Haukka, Matti,Pombeiro, Armando J.L.,Shul'Pin, Georgiy B.
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experimental part
p. 26 - 34
(2012/01/14)
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- Mild, single-pot hydrocarboxylation of linear C5-C9 alkanes into branched monocarboxylic C6-C10 acids in copper-catalyzed aqueous systems
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A single-pot method has been developed for the hydrocarboxylation of the liquid C5-C9 alkanes (n-pentane, n-hexane, n-heptane, n-octane, n-nonane and 3-methylhexane) into the branched monocarboxylic C 6-C10 acids bearing one more carbon atom. This method is characterized by a direct, selective and low-temperature (60 °C) hydrocarboxylation reaction of the alkane with carbon monoxide, water (which acts as a reagent besides being a solvent component) and potassium peroxodisulfate, in H2O/MeCN medium. The hydrocarboxylations are markedly enhanced in the presence of a tetracopper(II) triethanolaminate complex as a homogeneous catalyst precursor. Total yields (based on alkane) of carboxylic acids up to 46% (with 97-99% overall selectivity) have been achieved, which are remarkable in the field of alkane functionalization under mild conditions, especially for a C-C bond formation reaction in aqueous acid-solvent-free medium. The regio- and bond selectivity parameters have been determined and a free radical mechanism has been proposed.
- Kirillova, Marina V.,Kirillov, Alexander M.,Pombeiro, Armando J.L.
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experimental part
p. 106 - 113
(2012/04/04)
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- Rearrangement of epoxynitriles: A convenient homologation of acyclic and cyclic ketones to carboxylic acids
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A convenient two-step homologation of both aliphatic and aromatic ketones to the corresponding carboxylic acid has been developed. First ketones were converted to epoxynitriles with the Darzens reaction. Second, a Lewis acid mediated rearrangement of these epoxynitriles with lithium bromide was achieved to give homologated secondary alkanoic acids (as well as aryl-alkanoic) in good yields. The mechanism and the scope of the rearrangement reaction were investigated. This strategy constitutes a two- step homologation of ketones to secondary carboxylic acids.
- Badham, Neil F.,Mendelson, Wilford L.,Allen, Andrew,Diederich, Ann M.,Eggleston, Drake S.,Filan, John J.,Freyer, Alan J.,Killmer Jr., Lewis B.,Kowalski, Conrad J.,Liu, Li,Novack, Vance J.,Vogt, Frederick G.,Webb, Kevin S.,Yang, Jennifer
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p. 5440 - 5443
(2007/10/03)
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- Conjugate addition of organolithium reagents to α,β-unsaturated carbocyclic acids
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Conjugate addition of primary, secondary, tertiary alkyi and phenyl lithium reagents to 2-alkenoic acids affords good yields of branched saturated carboxylic acids. Methyl groups at the α- and β-carbon of the 2-alkenoic acid decrease reactivity as acceptors, and foster deprotonation, respectively. The lithium enediolate resulting from the conjugate addition can react with electrophiles. PM3 calculations are in agreement with the substituent effects.
- Aurell, Maria Jose,Domingo, Luis Ramon,Mestres, Ramon,Munos, Elena,Zaragoza, Ramon Jose
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p. 815 - 830
(2007/10/03)
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- Regioselective effect of CoCl2 in olefin hydrocarboxylation catalyzed by PdCl2(Ph3P)2 complex
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The kinetics of the catalytic reactions of 1-heptene and styrene with CO (0.5-3 MPa) and water in dioxane over the PdCl2(Ph3P)2-complex catalyst doped with CoCl2 (383 K) is studied. The introduction of the CoCl2 promoter is found to enhance the selectivity with respect to linear carboxylic acids, whereas the kinetic regularities of these reactions remain essentially unchanged. Numerical simulations of the kinetics of the process under study suggest that the observed effects are due to the formation of a new catalytic form Pd(0), presumably of the heterobinuclear type.
- Kron,Terekhova,Noskov,Petrov
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p. 1665 - 1669
(2007/10/03)
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- Influence of cobalt carbonyl on the rate and regioselectivity of the hydrocarboxylation of 1-heptene with catalysis by the complex PdCl2(Ph3P)2
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The hydrocarboxylation rate of 1-heptene is reduced and the selectivity with respect to n-octanoic acid is increased when Co2(CO)8 is added to the catalyst of the reaction - the complex PdCl2(Ph3P)2. According to the results of kinetic measurements and data of IR spectroscopy in situ, the effect of cobalt carbonyl is due to the fact that it blocks the process along the least selective path with the participation of a biscarbonyl hydride intermediate of palladium. Copyright
- Terekhova,Kron,Noskov,Petrov
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p. 331 - 337
(2007/10/03)
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- Mechanism of hydrocarboxylation of alkenes catalyzed by triphenylphosphine complexes of palladium
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The kinetics of hydrocarboxylation of 1-heptene, catalyzed by the PdCl2(Ph3P)2 complex, in dioxane at 110°C at 1-10 mol/1 water and 0.6-3 MPa CO is studied. The dependences of initial accumulation rates of regioisomeric products on the CO pressure and concentrations of water and triphenylphosphine agree with the mechanism proposed for the reaction involving three types of hydrogenated complexes, HPdClL2-m(CO)m (m = 0-2), under the condition of irreversibility of the formation of alkyl intermediates on the routes of formation of both linear and branched products, including an additional route that involves the formation of a linear product with the participation of the complex with m = 2.
- Kron,Noskov,Terekhova,Petrov
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- PROMOTING EFFECT OF HCl IN THE Pd-CATALYZED HYDROCARBOXYLATION OF OLEFINS
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The addition of Pd(Ph3P)4 to the PdCl2(Ph3P)2 catalyst reduces the rate of the catalytic hydrocarboxylation of styrene, propylene, and 1-heptene in spite of the increase in the concentration of Pd in the reaction mixture. With styrene the reaction also becomes more regioselective with respect to the linear product. The addition of Pd(Ph3P)4 is presumed to reduce the concentration of free HCl, which takes part in the catalytic process along with the Pd intermediates.
- Petrova, N. E.,Noskov, Yu. G.,Terekhova, M. I.,Petrov, E. S.
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p. 478 - 480
(2007/10/02)
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- COMPLEXES OF PdCl2 WITH PHOSPHORYL- AND THIOPHOSPHORYL-SUBSTITUTED PHOSPHINES AS CATALYSTS FOR THE HYDROCARBOXYLATION OF OLEFINS
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The influence of the ligands Ph2P(CH2)mP(X)Ph2(L), where m = 1, 2 and X = O, S, on the rate and regional selectivity of the hydrocarboxylation of α-olefins has been investigated, catalyzed by PdCl2, in a series of organic solvents.A high regional selectivity of the process (>80percent) for products with normal structure has been achieved by using L with m = 2, X = O.The influence of the ligand used and of triphenylphosphine on the properties of the catalytic system in the given reaction has been compared. Keywords: hydrocarboxylation, palladium chloride complexes, bidentate diphosphines, catalysis.
- Terekhova, M. I.,Kron, T. E.,Bondarenko, N. A.,Petrov, E. S.,Tsvetkov, E. N.
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p. 1555 - 1558
(2007/10/02)
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- CATALYTIC SYSTEM PdCl2/Ph2PC6H4SO3Na IN HYDROCARBOXYLATION OF 1-HEPTENE
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The catalytic system PdCl2/Ph2PC6H4SO3Na-m in the hydrocarboxylation of olefins is more effective than an analogous system with Ph3P, and it allows the reaction to be carried out in media with considerably higher contents of water.
- Starosel'skaya, L. F.,Kron, T. E.,Terekhova, M. I.,Petrov, E. S.
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p. 668 - 671
(2007/10/02)
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- DIRECT, REGIOSELECTIVE HYDROCARBOXYLATION OF ALKYNES TO SATURATED ACIDS BY COBALT AND NICKEL CATALYSTS UNDER PHASE TRANSFER CONDITIONS
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Phase transfer catalyzed carbonylation of alkynes in the presence of cobalt chloride, potassium cyanide, and nickel cyanide affords saturated carboxylic acids, with good selectivity observed for the branched-chain isomer.
- Lee, Jong-Tae,Alper, Howard
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p. 1769 - 1770
(2007/10/02)
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- A Facile Method for Synthesis of Three Carbon-Homologated Carboxylic Acid by Regioselective Ring-opening of β-Propiolactones with Organocopper Reagents
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Organocopper reagents, such as diorganocuprates, organocopper-tributylphosphine, and Grignard reagents in the presence of a copper (I) salt, reacted with β-propiolactones by regioselective β-carbon-oxygen fission to give 3-substituted propionic acids.Among these three kinds of organocopper reagents, diorganocuprate, especially halomagnesium cuprate gave the highest yields of the acids, which was remarkably observed in the ring-opening of sterically hindered β-propiolactones such as β-methyl- and α,β-dimethyl-β-propiolactones and also in the reactions using the organocopper reagents with vinyl and allyl substituents.The ring-opening of β-propiolactone was confirmed to proceed by SN2 pathway with predominant inversion of configuration of the β-carbon by using the reaction of cis-α,β-dimethyl-β-propiolactone with di-tert-butylcuprate to afford syn-2,3,4,4-tetramethylpentanoic acid.
- Kawashima, Masatoshi,Sato, Toshio,Fujisawa, Tamotsu
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p. 403 - 412
(2007/10/02)
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- Peptide immunostimulants
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Peptide compounds of formula 1, pharmaceutically acceptable base salts thereof, pharmaceutical compositions and their use as antiinfective agents where R1 is alkyl, cycloalkyl or cycloalkylmethyl; R2 is hydrogen or alkyl and R3 is hydroxy or an amino acid residue of the formula where X is hydrogen, alkyl or hydroxymethyl and nis an integer of 0 to 4 and R4 and R5 are alkyl, hydrogen, benzyl or cyclohexylmethyl.
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- A THREE CARBON HOMOLOGATION BY THE RING-OPENING OF β-PROPIOLACTONES WITH DIORGANOCUPRATES
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Various organocuprates react with β-propiolactones to give β-substituted propionic acids in high yields.
- Fujisawa, Tamotsu,Sato, Toshio,Kawara, Tatsuo,Kawashima, Masatoshi
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p. 2181 - 2184
(2007/10/02)
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- COPPER-CATALYZED REACTION OF GRIGNARD REAGENTS WITH β-PROPIOLACTONES: A CONVENIENT METHOD FOR THE SYNTHESIS OF Β-SUBSTITUTED PROPIONIC ACIDS
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Grignard reagents react with β-propiolactones in the presence of a copper(I) catalyst to give β-substituted propionic acids in high yields.
- Sato, Toshio,Kawara, Tatsuo,Kawashima, Masatoshi,Fujisawa, Tamotsu
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p. 571 - 574
(2007/10/02)
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