- Elucidating the Supramolecular Copolymerization of N- and C-Centered Benzene-1,3,5-Tricarboxamides: The Role of Parallel and Antiparallel Packing of Amide Groups in the Copolymer Microstructure
-
An in-depth study of the supramolecular copolymerization behavior of N- and C-centered benzene-1,3,5-tricarboxamides (N- and C-BTAs) has been conducted in methylcyclohexane and in the solid state. The connectivity of the amide groups in the BTAs differs, and mixing N- and C-BTAs results in supramolecular copolymers with a blocky microstructure in solution. The blocky microstructure results from the formation of weaker and less organized, antiparallel hydrogen bonds between N- and C-BTAs. In methylcyclohexane, the helical threefold hydrogen-bonding network present in C- and N-BTAs is retained in the mixtures. In the solid state, in contrast, the hydrogen bonds of pure BTAs as well as their mixtures organize in a sheet-like pattern, and in the mixtures long-range order is lost. Drop-casting to kinetically trap the solution microstructures shows that C-BTAs retain the helical hydrogen bonds, but N-BTAs immediately adopt the sheet-like pattern, a direct consequence of the lower stabilization energy of the helical hydrogen bonds. In the copolymers, the stability of the helical aggregates depends on the copolymer composition, and helical aggregates are only preserved when a high amount of C-BTAs is present. The method outlined here is generally applicable to elucidate the copolymerization behavior of supramolecular monomers both in solution as well as in the solid state.
- de Windt, Lafayette N. J.,Fernández, Zulema,Fernández-Míguez, Manuel,Freire, Félix,Palmans, Anja R. A.
-
supporting information
(2021/12/06)
-
- An efficient and ultrastable single-Rh-site catalyst on a porous organic polymer for heterogeneous hydrocarboxylation of olefins
-
A heterogeneous hydrocarboxylation process of olefins to obtain carboxylic acids with one more carbon was first realized using a single-Rh-site catalyst formed on porous organic polymer (Rh1/POPs). The in situ formation of hydrophilic porous ionic polymer from hydrophobic POPs with the help of CH3I led to high activity and superb stability.
- Yuan, Qiao,Song, Xiangen,Feng, Siquan,Jiang, Miao,Yan, Li,Li, Jingwei,Ding, Yunjie
-
supporting information
p. 472 - 475
(2021/01/25)
-
- A direct synthesis of carboxylic acidsviaplatinum-catalysed hydroxycarbonylation of olefins
-
The platinum-catalysed hydroxycarbonylation of olefins is reported for the first time. Using a combination of PtCl2/2,2′-bis(tert-butyl(pyridin-2-yl)phosphanyl)-1,1′-binaphthalene (Neolephos) in the presence of sulfuric acid [0.6 M] in acetic acid selective carbonylation of terminal aliphatic olefins proceeds to good yields and selectivities to the corresponding carboxylic acids. Comparing the reactivity of different butenes (iso- andn-butenes), the terminal olefin can be selectively carbonylated.
- Schneider, Carolin,Franke, Robert,Jackstell, Ralf,Beller, Matthias
-
p. 2703 - 2707
(2021/05/05)
-
- DISCOVERY, TOTAL SYNTHESIS, AND BIOACTIVITY OF DOSCADENAMIDES
-
The invention is directed towards compounds (e.g., Formulae (I)-(IX)), their mechanism of action, processes to prepare the compounds, methods of activating quorum sensing signaling activity, and methods of treating diseases and disorders using the compounds described herein (e.g., Formulae (I)-(IX)).
- -
-
Page/Page column 111; 113-114
(2021/02/05)
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- Bifunctional Doscadenamides Activate Quorum Sensing in Gram-Negative Bacteria and Synergize with TRAIL to Induce Apoptosis in Cancer Cells
-
New cyanobacteria-derived bifunctional analogues of doscadenamide A, a LasR-dependent quorum sensing (QS) activator in Pseudomonas aeruginosa, characterized by dual acylation of the pyrrolinone core structure and the pendant side chain primary amine to form an imide/amide hybrid are reported. The identities of doscadenamides B-J were confirmed through total synthesis and a strategic focused library with different acylation and unsaturation patterns was created. Key molecular interactions for binding with LasR and a functional response through mutation studies coupled with molecular docking were identified. The structure-activity relationships (SARs) were probed in various Gram-negative bacteria, including P. aeruginosa and Vibrio harveyi, indicating that the pyrrolinone-N acyl chain is critical for full agonist activity, while the other acyl chain is dispensable or can result in antagonist activity, depending on the bacterial system. Since homoserine lactone (HSL) quorum sensing activators have been shown to act in synergy with TRAIL to induce apoptosis in cancer cells, selected doscadenamides were tested in orthogonal eukaryotic screening systems. The most potent QS agonists, doscadenamides S10-S12, along with doscadenamides F and S4 with partial or complete saturation of the acyl side chains, exhibited the most pronounced synergistic effects with TRAIL in triple negative MDA-MB-231 breast cancer cells. The overall correlation of the SAR with respect to prokaryotic and eukaryotic targets may hint at coevolutionary processes and intriguing host-bacteria relationships. The doscadenamide scaffold represents a non-HSL template for combination therapy with TRAIL pathway stimulators.
- Liang, Xiao,Chen, Qi-Yin,Seabra, Gustavo M.,Matthew, Susan,Kwan, Jason C.,Li, Chenglong,Paul, Valerie J.,Luesch, Hendrik
-
supporting information
p. 779 - 789
(2021/02/06)
-
- Ruthenium-catalysed hydroxycarbonylation of olefins
-
State-of-the-art catalyst systems for hydroxy- and alkoxycarbonylations of olefins make use of palladium complexes. In this work, we report a complementary ruthenium-catalysed hydroxycarbonylation of olefins applying an inexpensive Ru-precursor (Ru3(CO)12) and PCy3as a ligand. Crucial for the success of this transformation is the use of hexafluoroisopropanol (HFIP) as the solvent in the presence of an acid co-catalyst (PTSA). Overall, moderate to good yields are obtained using aliphatic olefins including the industrially relevant substrate di-isobutene. This atom-efficient catalytic transformation provides straightforward access to various carboxylic acids from unfunctionalized olefins.
- Dühren, Ricarda,Kucmierczyk, Peter,Jackstell, Ralf,Franke, Robert,Beller, Matthias
-
p. 2026 - 2030
(2021/04/09)
-
- Process for the preparation of fatty acids
-
The invention discloses a method for preparing fatty acid. The method comprises the following steps: providing a first reactant which is a furan compound containing an carbonyl group; providing a second reactant which is a compound containing a carboxyl group, an ester group or an anhydride group and can participate in a condensation reaction with the carbonyl group of the first reactant; allowingthe first reactant and the second reactant to participate in a first condensation reaction, and allowing a C=O bond of the carbonyl group of the first reactant to be connected with alpha carbon of the carbonyl group of the second reactant and to be converted into a C=C bond so as to form a condensation product; and carrying out a second-step reaction under hydrogen pressure in the presence of a co-catalytic system of a hydrogenation catalyst and Lewis acid, opening a furan ring of the condensation product, carrying out hydrodeoxygenation at the same time, removing all oxygen except for oxygenin the carboxyl group, and allowing a carbon chain to be saturated so as to obtain the fatty acid.
- -
-
Paragraph 0179-0206; 0236-0238
(2020/09/04)
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- Pd-Catalyzed Highly Chemo- And Regioselective Hydrocarboxylation of Terminal Alkyl Olefins with Formic Acid
-
An efficient Pd-catalyzed hydrocarboxylation of alkenes with HCOOH is described. A wide variety of linear carboxylic acids bearing various functional groups can be obtained with excellent chemo- and regioselectivities under mild reaction conditions. The reaction process is operationally simple and requires no handling of toxic CO.
- Ren, Wenlong,Chu, Jianxiao,Sun, Fei,Shi, Yian
-
supporting information
p. 5967 - 5970
(2019/08/26)
-
- Mild C-H functionalization of alkanes catalyzed by bioinspired copper(ii) cores
-
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)
-
- PROCESS FOR THE DIRECT CONVERSION OF ALKENES TO CARBOXYLIC ACIDS
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Process for the direct conversion of alkenes to carboxylic acids.
- -
-
Paragraph 0029-0032
(2019/07/10)
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- 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
-
supporting information
p. 14365 - 14373
(2019/09/06)
-
- Carbonylative Transformation of Allylarenes with CO Surrogates: Tunable Synthesis of 4-Arylbutanoic Acids, 2-Arylbutanoic Acids, and 4-Arylbutanals
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In this Communication, procedures for the selective synthesis of 4-arylbutanoic acids, 2-arylbutanoic acids, and 4-arylbutanals from the same allylbenzenes have been developed. With formic acid or TFBen as the CO surrogate, reactions proceed selectively and effectively under carbon monoxide gas-free conditions.
- Wu, Fu-Peng,Li, Da,Peng, Jin-Bao,Wu, Xiao-Feng
-
supporting information
p. 5699 - 5703
(2019/08/01)
-
- 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
-
supporting information
p. 3967 - 3970
(2018/04/23)
-
- 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 68; 69; 70; 71; 72
(2018/02/28)
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- Catalytic Regio- and Enantioselective Alkylation of Conjugated Dienyl Amides
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A method for catalytic asymmetric alkylation of conjugated dienyl amides has been developed and it allows efficient and high-yielding transformations of a wide range of polyconjugated amides into the corresponding chiral products. Smooth addition of organomagnesium reagents to relatively unreactive dienyl amides with excellent 1,6- and 1,4-selectivities, as well as enantioselectivites above 90 %, is achieved owing to the complementary action of the Lewis acid and a chiral copper-based catalyst.
- Guo, Yafei,Kootstra, Johanan,Harutyunyan, Syuzanna R.
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p. 13547 - 13550
(2018/09/25)
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- A Ligand-Directed Catalytic Regioselective Hydrocarboxylation of Aryl Olefins with Pd and Formic Acid
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An effective Pd-catalyzed hydrocarboxylation of aryl olefins with Ac2O and formic acid is described. A variety of 2- and 3-arylpropanoic acids can be regioselectively formed by the judicious choice of ligand without the use of toxic CO gas.
- Liu, Wei,Ren, Wenlong,Li, Jingfu,Shi, Yuan,Chang, Wenju,Shi, Yian
-
supporting information
p. 1748 - 1751
(2017/04/11)
-
- 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)
-
- Site-Selective Catalytic Carboxylation of Unsaturated Hydrocarbons with CO2 and Water
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A catalytic protocol that reliably predicts and controls the site-selective incorporation of CO2 to a wide range of unsaturated hydrocarbons utilizing water as formal hydride source is described. This platform unlocks an opportunity to catalytically repurpose three abundant, orthogonal feedstocks under mild conditions.
- Gaydou, Morgane,Moragas, Toni,Juliá-Hernández, Francisco,Martin, Ruben
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p. 12161 - 12164
(2017/09/12)
-
- 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)
-
- Structure-property relationships in a series of diglycerol tetraether model lipids and their lyotropic assemblies: The effect of branching topology and chirality
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Three novel diglycerol tetraether lipids with one membrane-spanning chain have been synthesized. These lipids contain only two or four racemic methyl branches at selected positions of the hydrophobic chains in contrast to natural lipids from archaebacterial membranes with an isoprenoid substitution pattern. The insertion of the methyl moieties was realized starting from either (RS)-citronellyl bromide or the inexpensive methyl malonic acid ethyl ester. For chain elongation the Cu-catalysed Grignard coupling reaction was used. The preparation of diglycerol tetraethers was either performed by condensing suitable blocked monoglycerol diethers by Grubbs metathesis or by reaction of the transmembrane C32-chain with blocked glycerols followed by further alkylation steps. Finally, we could show that the resulting lipids can form closed lipid vesicles comparable to the optically pure counterparts. Therefore, these much simpler lipids compared to the natural lipids from archaebacterial membranes are also suitable for preparation of stable tailored liposomes. This journal is the Partner Organisations 2014.
- Markowski, Thomas,Drescher, Simon,Meister, Annette,Blume, Alfred,Dobner, Bodo
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p. 3649 - 3662
(2014/06/09)
-
- SPIROBENZYLAMINE-PHOSPHINE, PREPARATION METHOD THEREFOR AND USE THEREOF
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The present invention relates to a spirobenzylamine-phosphine, preparation method therefor and use thereof. The compound has a structure represented by formula (I), wherein n=0 to 3; R1, R2, R3, R4, R5, R6, R7, R8 and R9 having a value as defined in claim 1. Starting from the substituted 7-trifluoromesyloxy-7'-diarylphosphino-1, 1'-spiro-dihydroindene, the compound is synthesized in a two-step or three-step reactions. The new spirobenzylamine-phosphine is complexed with an iridium precursor and is subjected to ion exchange, to give an Iridium/spirobenzylamine-phosphine complex comprising various anions. The spiro benzyl amine-phosphine/Iridium complex according to the present invention may be used for catalyzing asymmetry hydrogenation of a variety of alpha-substituted acrylic acids, has high activity and enantio-selectivity, and has a good prospect of industrialization.
- -
-
Paragraph 0067
(2014/07/22)
-
- Spirobenzylamine-Phosphine, Preparation Method Therefor And Use Thereof
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The present invention relates to a spirobenzylamine-phosphine, preparation method therefor and use thereof. The compound has a structure represented by formula (I), wherein n=0 to 3; R1, R2, R3, R4, R5, R6, R7, R8 and R9 having a value as defined in claim 1. Starting from the substituted 7-trifluoromesyloxy-7′-diarylphosphino-1,1′-spiro-dihydroindene, the compound is synthesized in a two-step or three-step reactions. The new spirobenzylamine-phosphine is complexed with an iridium precursor and is subjected to ion exchange, to give an Iridium/spirobenzylamine-phosphine complex comprising various anions. The spiro benzyl amine-phosphine/Iridium complex according to the present invention may be used for catalyzing asymmetry hydrogenation of a variety of alpha-substituted acrylic acids, has high activity and enantio-selectivity, and has a good prospect of industrialization.
- -
-
Paragraph 0080; 0081
(2014/07/22)
-
- Oxidative rearrangement of malondialdehyde: Substrate scope and mechanistic insights
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A novel oxidative rearrangement of malondialdehyde was described. Under the effect of H2O2, malondialdehyde smoothly transferred to carboxylic acid with C-C bond cleavage in good to excellent yields. Mechanistic studies showed that this reaction proceeded via the formation of a 1,2-dioxolane intermediate, followed by concert C-C, O-O, C-H bond cleavage and a hydride shift.
- Yu, Xin,Liu, Zheng,Xia, Zilei,Shen, Zhigao,Pan, Xixian,Zhang, Hui,Xie, Weiqing
-
p. 53397 - 53401
(2015/01/16)
-
- Use of ethyl (benzothiazol-2-ylsulfonyl)acetate for malonic ester-type syntheses of carboxylic acids and esters
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A new methodology for the synthesis of substituted carboxylic acids is described. Alkylation of either ethyl (benzothiazol-2-ylsulfonyl)acetate or ethyl 2-(benzothiazol-2-ylsulfonyl)propionate was achieved with alkyl halides and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in dichloromethane solution. These products were then desulfinated and hydrolysed in one-pot under mild conditions to give substituted acetic acids in good-to-excellent yields.
- Hussein, Waleed M.,McGeary, Ross P.
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p. 1222 - 1227
(2014/10/16)
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- Carbon dioxide as a C1 building block for the formation of carboxylic acids by formal catalytic hydrocarboxylation
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A happy marriage of two processes: An effective catalytic system was identified for the direct synthesis of carboxylic acids from non-activated olefins or alcohols, CO2, and H2. Detailed analysis together with labeling studies indicated that the overall hydrocarboxylation of simple olefins results from a combination of the reverse water-gas shift (rWGS) reaction and a hydroxycarbonylation step, each promoted by a rhodium catalyst (see scheme). Copyright
- Ostapowicz, Thomas G.,Schmitz, Marc,Krystof, Monika,Klankermayer, Juergen,Leitner, Walter
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p. 12119 - 12123
(2013/12/04)
-
- 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)
-
- 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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- Enantioselective hydrogenation of α-substituted acrylic acids catalyzed by iridium complexes with chiral spiro aminophosphine ligands
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Highly active: Iridium complexes with chiral spiro aminophosphine ligands were synthesized and applied as catalysts for the asymmetric hydrogenation of α-substituted acrylic acids (see scheme). The complexes were highly active catalysts, showing turnover frequencies of up to 6000 h-1, and catalyst loadings could be reduced to 0.01 mol %. Copyright
- Zhu, Shou-Fei,Yu, Yan-Bo,Li, Shen,Wang, Li-Xin,Zhou, Qi-Lin
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supporting information; experimental part
p. 8872 - 8875
(2012/10/08)
-
- 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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- Volatile methyl esters of medium chain length from the bacterium Chitinophaga Fx7914
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The analysis of the volatiles released by the novel bacterial isolate Chitinophaga Fx7914 revealed the presence of ca. 200 compounds including different methyl esters. These esters comprise monomethyl- and dimethyl-branched, saturated, and unsaturated fatty acid methyl esters that have not been described as bacterial volatiles before. More than 30 esters of medium C-chain length were identified, which belong to five main classes, methyl (S)-2-methylalkanoates (class A), methyl (S)-2,(ω-1)-dimethylalkanoates (class B), methyl 2,(ω-2)-dimethylalkanoates (class C), methyl (E)-2-methylalk-2-enoates (class D), and methyl (E)-2,(ω-1)-dimethylalk-2- enoates (class E). The structures of the compounds were verified by GC/MS analysis and synthesis of the target compounds as methyl (S)-2-methyloctanoate (28), methyl (S)-2,7-dimethyloctanoate ((S)-43), methyl 2,6-dimethyloctanoate (49), methyl (E)-2-methylnon-2-enoate (20a), and methyl (E)-2,7-dimethyloct-2- enoate (41a). Furthermore, the natural saturated 2-methyl-branched methyl esters showed (S)-configuration as confirmed by GC/MS experiments using chiral phases. Additionally, the biosynthetic pathway leading to the methyl esters was investigated by feeding experiments with labeled precursors. The Me group at C(2) is introduced by propanoate incorporation, while the methyl ester is formed from the respective carboxylic acid by a methyltransferase using S-adenosylmethionine (SAM).
- Nawrath, Thorben,Gerth, Klaus,Mueller, Rolf,Schulz, Stefan
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p. 2228 - 2253
(2011/05/17)
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- Lyzed isomerization and hydroformylation of olefins
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The palladium-catalyzed hydroformylation of 1-octene has been studied in the presence of different phosphines and acid cocatalysts. The best results are achieved in the presence of in situ-generated palladium complexes with bidentate phosphines. It is demonstrated that the acid concentration is a crucial factor for obtaining high linear selectivity. A novel optimized catalyst based on an arylheteroarylphosphine has been applied for hydroformylation of different aliphatic and aromatic olefins. Good activity and excellent selectivity towards the linear aldehydes is achieved.
- Jennerjahn, Reiko,Piras, Irene,Jackstell, Ralf,Franke, L Robert,Wiese, Klaus-Diether,Beller, Thias
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experimental part
p. 6383 - 6388
(2010/01/16)
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- Hydrocarboxylation of terminal alkenes in supercritical carbon dioxide
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The catalytic hydrocarboxylation of linear alkenes to carboxylic acids using supercritical carbon dioxide as a solvent was studied. High selectivities in acids have been obtained. The best results were achieved when adding a perfluorinated surfactant to the reaction mixture (93% conversions and ca. 80% selectivity). Comparative multinuclear high-pressure NMR spectroscopic studies in [D8]THF and in supercritical CO2 show the formation of Pd0 species. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Estorach, Clara Tortosa,Orejon, Arantxa,Ruiz, Nuria,Masdeu-Bulto, Anna M.,Laurenczy, Gabor
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experimental part
p. 3524 - 3531
(2009/02/07)
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- Hydrocarboxylation of terminal alkenes in supercritical carbon dioxide using perfluorinated surfactants
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High selectivity in acids is obtained in the first example of hydrocarboxylation of 1-octene in supercritical carbon dioxide using a Pd/P(4-C6H4-CF3)3 catalyst system and a perfluorinated surfactant. The Royal Society of Chemistry 2006.
- Tortosa-Estorach, Clara,Ruiz, Nuria,Masdeu-Bulto, Anna M.
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p. 2789 - 2791
(2008/09/19)
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- Radical-mediated Carbonylation of Alkyl Iodides in Aqueous Media
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Radical-mediated single carbonylation of alkyl iodides furnishing carboxylic acids proceeded in water using phosphinic acid as a radical initiator in the presence of a surfactant (CTAB). On the other hand, formation of double carbonylation product (α-keto carboxylic acid) along with single carbonylation product was observed for the first time, when the reaction was carried out in aqueous ethanol without any surfactants.
- Sugiura, Masaharu,Hagio, Hiroyuki,Kobayashi, Shu
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p. 898 - 899
(2007/10/03)
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- Tumor chemopreventive activity of 3-O-acylated (-)-epigallocatechins
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In order to seek promising cancer chemopreventive agents, we assessed the antitumor promoting activities of 3-O-octanoyl- or 3-O-(2-methyloctanoyl)-(-)- epigallocatechins, inhibiting markedly the activation of Epstein-Barr virus early antigen, in a two-stage mouse skin carcinogenesis assay. As a result, these derivatives inhibited a papilloma formation 1.3-1.6-fold more strongly than (-)-epigallocatechin gallate well established as anti-tumor promoter.
- Kumagai, Ayako,Nagaoka, Yasuo,Obayashi, Tomoko,Terashima, Yasuhiro,Tokuda, Harukuni,Hara, Yukihiko,Mukainaka, Teruo,Nishino, Hoyoku,Kuwajima, Hiroshi,Uesato, Shinichi
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p. 5143 - 5148
(2007/10/03)
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- Resolution of 2-methylalkanoic acids. Enantioselective esterification with long chain alcohols catalysed by Candida rugosa lipase
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Candida rugosa lipase catalysed resolutions of 2-methylalkanoic acids run on a large scale often display decreased enantiomeric rations (E-values) and reaction rates compared with small-scale experiments. By continuous control of the water activity (addition of inorganic salt/hydrated salt mixtures) this can be avoided. The importance of the proper choice of alcohol as well as its concentration is demonstrated. (R)-2-Methyloctanoic acid (8.6g) and (S)-2-methyl-1-octanol (4.5 g), both in 99.6% ee were prepared from 20 g racemic 2-methyloctanoic acid. Acta Chemica Scandinavica 1996.
- Edlund,Berglund,Jensen,Hedenstroem,Hoegberg
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p. 666 - 671
(2007/10/03)
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- Sex pheromone of the pine sawfly Diprion pini (Hymenoptera: Diprionidae): Chemical identification, synthesis and biological activity
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The main component of the sex pheromone secretion of female Diprion pini L. (Hymenoptera: Diprionidae) from insects collected both in Finland and in France has been identified as a threo-3,7-dimethyl-2-tridecanol 8 ng per female) stereoisomer by GC-MS and synthesis. The secretion also contains lower and higher homologues in small amounts (1-4% of the main component). Combined gas chromatograghic-electroantennographic detection showed activity in both natural and esterified extracts (acetates and propionates); the esters of the main component gave the largest responses. The acetates and propionates of the eight stereoisomers of 3,7-dimethyl-2-tridecanol were synthesized from enantiomerically highly enriched (> 99% ee) building blocks. The stereochemistry of the main component was established to be (2S,3R,7R)-3,7-dimethyl-2-tridecanol by GC analysis of the natural material. It was purified by liquid chromatography prior to the GC analysis of both its pentafluorobenzoates and its isopropylcarbamates on a non-chiral polar column (ECD) and a chiral column (NPD), respectively. Field tests demonstrated that both the acetate and propionate of the main component (100 μg of each applied on cotton roll dispensers) were active in attracting males, with or without the presence of several of the minor compounds. Experiments with smaller amounts of the acetate and the propionate (1 μg in France and 50 μg in Finland) demonstrated that the propionate was more active than the acetate, and that it also caught more males than a blend of the two compounds.
- Bergstroem,Wassgren,Anderbrant,Faegerhag,Edlund,Hedenstroem,Hoegberg,Geri,Auger,Varama,Hansson,Loefqvist
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p. 370 - 380
(2007/10/02)
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- Total synthesis and structure assignment of the antitumor antibiotic aranorosin
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The structurally unique antifungal and antitumor antibiotic aranorosin was prepared in a convergent, stereoselective sequence. Oxidative cyclization of N-protected L-tyrosine, followed by face-selective 1,2-addition of [(benzyloxy)methyl]lithium, Henbest oxidation in the presence of Kishi's radical inhibitor, and simultaneous N,O-deprotection led to an amino diol which was N-acylated with the fatty acid side-chain segment. After a low-temperature reduction of the lactone moiety to the lactol, the carbonyl function was regenerated under neutral conditions by diol cleavage with sodium periodate. Preparation of the acid side chain involved a diastereoselective imide α-alkylation directed by Evans' oxazolidinone auxiliary, followed by a series of Wittig-Horner chain extensions. Since the relative configuration at the C(6') position of the natural product had not been determined, we prepared both the (6'S) and the (6'R) isomers of aranorosin. Comparison of synthetic material with the reported spectral data for natural (-)-aranorosin, especially 1H and 13C NMR and [α](D), did not allow a definitive assignment. After purification of a sample of the isolated material from Pseudoarachniotus roseus the corrected [α](D) strongly indicated the (6'R)-stereochemistry for the natural compound. This assignment was confirmed by circular dichroism spectra for (6'S)- and (6'R)-aranorosin and the natural material.
- Wipf,Kim,Fritch
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p. 7195 - 7203
(2007/10/02)
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- 2-Methylalkanoic acids resolved by esterification catalysed by lipase from Candida rugosa: Alcohol chain length and enantioselectivity
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Enantiomerically pure (R)-2-methyldecanoic acid and (S)-2-methyl-1-decanol were prepared in a multi gram scale by esterification reactions catalysed by lipase from Candida rugosa. The enantiomeric ratios (E-values) were determined as a function of the chain length of the alcohol used as the complementary substrate in cyclohexane. In the resolution of 2-methyldecanoic acid the highest value (E = 37 ± 5) was obtained, when either 2-hexanol, 1-heptanol or 1-octanol were used. In contrast, when resolving 2-methyloctanoic acid, the E-values increased continually with increasing chain length of the alcohol used. 1-Hexadecanol gave the highest value: E > 100. The E-values were determined from the enantiomeric excess (ee) of the product at a conversion below 0.4. After two consecutive esterification reactions enantiomerically pure (R)-2-methyldecanoic acid, >99.8% ee, and after subsequent reduction of the ester produced, (S)-2-methyl-1-decanol, 96.7% ee, were obtained.
- Berglund,Holmquist,Hedenstrom,Hult,Hogberg
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p. 1869 - 1878
(2007/10/02)
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- Lipase-catalyzed resolution of racemic 2-alkyl substituted 1-alkanols
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(R)-2-alkyl-1-alkanoids (R)-1 with high optical purities were obtained by lipase-catalyzed esterification of the racemic substrates (R,S)-1 with vinyl acetate in dichloromethane. The alcohols (R)-1 were oxidized without racemization to the corresponding carboxylic acids (R)-4. The enriched (S)-acetates (S)-3 either were saponified to the alcohols (S)-1 which are substrates for a second lipase-catalyzed transesterification to give (S)-1 in high optical purity or were racemized and applied once again in the kinetic resolution to prepare (R)-1.
- Barth,Effenberger
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p. 823 - 833
(2007/10/02)
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- Asymmetric synthesis of α-methyl carboxylic acid derivatives stereochemistry in acidic ring opening of epoxides
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Optically active α-methyl carboxylic acid derivatives were prepared via reaction of microbially produced epoxides with trimethylaluminum. Stereochemistry of the ring opening reaction was discussed through an MO calculation.
- Fukumasa,Furuhashi,Umezawa,Takahashi,Hirai
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p. 1059 - 1062
(2007/10/02)
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- Process for the production of carboxylic acid esters and/or carboxylic acids
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Carboxylic acid esters are produced by reacting an unsaturated hydrocarbon, for example an olefin or an alkyne, with carbon monoxide and an alcohol in the presence of a protonic acid and as catalyst (a) at least one of the metals palladium, rhodium, ruthenium, iridium and cobalt, and (b) copper. In a modification of the invention carboxylic acids are produced by omitting the alcohol reactant and replacing it with water in an amount up to 8 mole equivalents based on the unsaturated hydrocarbon and a solvent other than an alochol, for example tetrahydrofuran.
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- A Conceptually Different Approach to the Asymmetric Synthesis of α-Substituted Carbonyl Compounds
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A new approach has been demonstrated for the asymmetric synthesis of α-substituted carbonyl compounds.Thus, the key assymetric carbon-carbon bond formation is accomplished by the highly diastereoselective addition of organoaluminum reagents to the chiral α,β-unsaturated acetal derived from the α,β-unsaturated aldehyde and (R,R)-tartaric acid diamide to furnish the 1,4-adduct preferentially along with the 1,2-adduct as a minor product.Subsequent oxidation of the combined adducts with ozone or the system potassium permanganate/sodium periodate gives rise to the optically active α-substituted aldehyde, ketone, or carboxylic acid, respectively, with high enantioselectivities.The present method has been applied to the facile synthesis of an anti-inflammatory agent and the principal alarm pheromone of the leaf-cutting ant Atta texana in optically active forms.
- Maruoka, Keiji,Nakai, Shuichi,Sakurai, Minoru,Yamamoto, Hisashi
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p. 130 - 132
(2007/10/02)
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- 3-Metalated Enamines, X. Formation and Reactivity of 1-(Diethoxphosphoryl)-1-(dimethylamino)allyl Anions
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1-Phosphorylenamines 8 and 10 react regio- and stereoselectively after deprotonation as anions 8A and 10A with silylating and alkylating reagents to give homologous (E)-1-phosphorylenamines 13, 15, 19-32.These can be hydrolyzed to give the corresponding carboxylic acids alkylated at C-3.Deprotonation of 10 occurs always on the methyl group cis to the phosphoryl group.The primarily formed anion isomerizes rapidly about the C-1 - C-2 bond.The highly regio- and stereoselective deprotonation allows the controlled introduction of up to three different alkyl groups.The results of NMR spectroscopic investigations of 8A and 10A are discussed.
- Ahlbrecht, Hubertus,Farnung, Winfried
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