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Synthesis and characterization of butylamine-functionalized Cr(III)–MOF–SO3H: Synergistic effect of the hydrophobic moiety on Cr(III)–MOF–SO3H in esterification reactions
Mesoporous solid acid catalysts with partially hydrophobic moieties, [Cr3O(BDC–SO3H)3?x(BDC–SO3NH3Bu)x]n, were prepared from [Cr3O(BDC–SO3H)3]n (MIL-101(Cr)–SO3H) and BuNH2 for the first time and then characterized by the Brunauer–Emmet–Teller (BET) technique, powder X-ray diffraction, field emission electron microscopy, Fourier transform infrared spectroscopy, and thermal and elemental analyses. The nitrogen adsorption–desorption study showed that the specific surface area and total pore volume of MIL-101(Cr)–SO3H decreased after the reaction with butylamine and formation of [Cr3O(BDC–SO3H)3?x(BDC–SO3NH3Bu)x]n. The prepared materials were used as catalysts to investigate the impact of hydrophobic moieties in esterification yields of phthalic anhydride with several alcohols as a probe reaction. The presence of butylamine as a hydrophobic group on MIL-101(Cr)–SO3H increases the esterification yield significantly for hydrophilic alcohols under solvent-free conditions. Moreover, results showed that [Cr3O(BDC–SO3H)3?x(BDC–SO3NH3Bu)x]n can be recovered and reused for several consecutive reactions without significant loss in catalyst activity.
Alavijeh, Masoumeh Karimi,Amini, Mostafa M.
(2019)
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Room temperature depolymerization of lignin using a protic and metal based ionic liquid system: an efficient method of catalytic conversion and value addition
Lignin is one of the most abundant biopolymer which can be utilized to synthesize various chemicalsviaits depolymerization. However, depolymerization of lignin generally occurs under very harsh conditions. Herein, we report the efficient depolymerization of ligninviadissolution in a mixed ionic liquid system: ethyl ammonium nitrate (EAN) + prolinium tetrachloromanganate(ii) [Pro]2[MnCl4] at 35 °C and under atmospheric pressure conditions. The high dissolution of lignin in ethyl ammonium nitrate provided a large number of H-bonding sites leading to the cracking of lignin and subsequent oxidative conversion by [Pro]2[MnCl4]viathe formation of metal-oxo bonding between Mn and lignin molecules. The extracted yield of vanillin was found to be 18-20% on lignin weight basisviaGC-MS analysis. The depolymerization of lignin was confirmed by SEM, FT-IR and PXRD analysis. Since lignin contains UV-absorbing functional groups, the regenerated biomass after the recovery of the depolymerized products was further utilized to synthesize a UV-shielding material. The constructed films from such a material exhibited a high SPF value of 22 and were found to be very effective by limiting the UV degradation of rhodamine B thus making the lignin valorization process economically viable and environmentally sustainable.
Mehta, Mohit J.,Kulshrestha, Akshay,Sharma, Shweta,Kumar, Arvind
p. 1240 - 1247
(2021/02/26)

Compound with AMPK agonistic activity and preparation and application of prodrug thereof
The invention relates to a compound with AMPK agonistic activity and a prodrug thereof, and as well as a preparation method and medical application of a prodrug thereof. The compound has the structure shown in the formula (I), and the prodrug of the compound has the structure shown in the formula (II), wherein each group and the substituent are as defined in the specification. The invention discloses a preparation method of the compound and application of the compound in prevention and treatment AMPK related diseases, and the AMPK related diseases include, but are not limited to, energy metabolism abnormality related diseases. Neurodegenerative diseases and inflammation-related diseases and the like.
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Paragraph 0145; 0151-0152; 0423-0426

(2021/10/27)

Lignin-fueled photoelectrochemical platform for light-driven redox biotransformation
The valorization of lignin has significant potential in producing commodity chemicals and fuels from renewable resources. However, the catalytic degradation of lignin is kinetically challenging and often requires noble metal catalysts to be used under harsh and toxic conditions. Here, we report the bias-free, solar reformation of lignin coupled with redox biotransformation in a tandem structure of a BiVO4 photoanode and perovskite photovoltaic. The tandem structure compensates for the potential gap between lignin oxidation and biocatalytic reduction through artificial Z-schematic absorption. We found that the BiVO4-catalyzed photoelectrochemical oxidation of lignin facilitated the fragmentation of higher molecular weight lignin into smaller carboxylated aliphatic and aromatic acids. Lignin oxidation induced photocurrent generation at the photoanode, which enabled efficient electroenzymatic reactions at the cathode. This study successfully demonstrates the oxidative valorization of lignin as well as biocatalytic reductions (e.g., CO2-to-formate and α-ketoglutarate-to-l-glutamate) in an unbiased biocatalytic PEC platform, which provides a new strategic approach for photo-biocatalysis using naturally abundant renewable resources.
Boonmongkolras, Passarut,Choi, Eun-Gyu,Han, Seunghyun,Kim, Jinhyun,Kim, Kayoung,Kim, Yong Hwan,Lee, Sahng Ha,Lee, Yang Woo,Park, Chan Beum,Shin, Byungha,Trang, Nguyen Vu Thien,Wang, Ding
supporting information
p. 5151 - 5160
(2020/08/25)

A Janus-type Heterogeneous Surfactant for Adipic Acid Synthesis
A highly water-dispersible heterogeneous Br?nsted acid surfactant was prepared by synthesis of a bi-functional anisotropic Janus-type material. The catalyst comprises ionic functionalities on one side and propyl-SO3H groups on the other. The novel material was investigated as a green substitute of a homogeneous acidic phase transfer catalyst (PTC). The activity of the catalyst was investigated for the aqueous-phase oxidation of cyclohexene to adipic acid with 30 % hydrogen peroxide even in a decagram-scale. It can also be used for the synthesis of some other carboxylic acid derivatives as well as diethyl phthalate.
Antonyuk, Sergiy,Breuninger, Paul,Ernst, Stefan,Thiel, Werner R.,Vafaeezadeh, Majid,Wilhelm, Christian
(2020/04/08)

Methods for preparing 1,2-cyclohexanedicarboxylate or phthalic acid ester
The invention relates to methods for preparing a plasticizer 1,2-cyclohexanedicarboxylate and phthalic acid ester by a biomass route. The preparation method of 1,2-cyclohexanedicarboxylate comprises the following steps: 1. crotonaldehyde, formaldehyde and fumarate (or maleate) are subjected to a D-A cycloaddition reaction under the catalysis of organic base so as to generate diester-substituted cyclohexenecarboxaldehyde; 2. the product is subjected to decarbonylation under a transition metal catalyst to generate cyclohexenedicarboxylate; and 3. cyclohexenedicarboxylate undergoes hydrogenationof a double bond under a transition metal catalyst to generate 1,2-cyclohexanedicarboxylate. The preparation method of phthalic acid ester comprises the following steps: 1. crotonaldehyde, formaldehyde and fumarate (or maleate) are subjected to a D-A cycloaddition reaction under the catalysis of organic base so as to generate diester-substituted cyclohexenecarboxaldehyde; and 2. the product undergoes decarbonylation/aromatization under a transition metal catalyst to generate phthalic acid ester.
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Paragraph 0066-0069

(2019/05/02)

Unprecedented alkylation of carboxylic acids by boron trifluoride etherate
The alkylation of carboxylic acids by an ethyl moiety of boron trifluoride etherate in the absence of ethyl alcohol from the reaction system is unexpected and novel. Both aromatic and aliphatic carboxylic acids were clearly alkylated affording good yields in short reaction times with the exception of nicotinic acid that necessitated an overnight reaction. It was noted that while ortho-substituted hydroxyl groups of carboxylic acids investigated were not affected by alkylation, those of meta- and para-substituted carboxylic acids were partially etherified. Furthermore, the alkylation reaction was found to be compatible with a range of functional groups such as halogens, amino and nitro groups except for the alkene function of undecylenic acid that underwent polymerisation with concomitant alkylation of its carboxylic acid function.
Jumbam, Ndze D.,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
p. 387 - 392
(2018/09/06)

CoIII-Catalyzed Isonitrile Insertion/Acyl Group Migration Between C?H and N?H bonds of Arylamides
A general efficient and site-selective cobalt-catalyzed insertion of isonitrile into C?H and N?H bonds of arylamides through C?H bond activation and alcohol assisted intramolecular trans-amidation is demonstrated. This straightforward approach overcomes the limitation by the presence of strongly chelating groups. Isolation of CoIII-isonitrile complex B has been achieved for the first time to understand the reaction mechanism.
Kalsi, Deepti,Barsu, Nagaraju,Sundararaju, Basker
supporting information
p. 2360 - 2364
(2018/02/22)

Diacidic ionic liquid supported on magnetic-silica nanocomposite: a novel, stable, and reusable catalyst for selective diester production
Abstract: Supported diacidic ionic liquid on magnetic silica nanoparticles (SDAIL@magnetic nanoSiO2) was successfully prepared through a multi-step approach. 2,2- bis ((3- methylimidazolidin-1-yl) methyl) propane- 1,3- diol bromide salt was immobilized onto the surface of magnetic silica nanoparticles via covalent bonding to prepare a novel powerful acidic catalyst. The synthesized catalyst was characterized by FT-IR, SEM, TGA, VSM, N2 adsorption–desorption measurements and acid-base titration. The catalytic activity of the prepared SDAIL@magnetic nanoSiO2 was investigated for the selective diesterification of alcohols by phthalic anhydride to afford corresponding dialkyl plasticizers under solvent-free conditions. The nature of two acidic counter anions as well as the presence of Lewis acidic species (Fe3O4) on the magnetic nanosilica and high surface area of the nanosilica influenced the behavior of the catalyst. Surperisingly, the high acidic character of the catalyst facilitates the reaction with a short reaction time. Furthermore, TG analysis strongly demonstrates that major content of IL is still stable on the support up to 290?°C, so catalyst has a good thermal stability. Under the optimized conditions, the conversion of phthalic anhydride was 100% and diester plasticizers were obtained with excellent yields (80–100%). The SDAIL@magnetic nanoSiO2 catalyst showed a good reusability and could be easily separated from the reaction mixture using an external magnet thanks to its superparamagnetic behavior and reused for several runs without significant activity loss. An important advantage of the SDAIL@magnetic nanoSiO2 was its high-hydrophilicity resulted in excellent selectivity towards the formation of only diesters which are commonly used plasticizers in different industries. Graphical abstract [Figure not available: see fulltext.].
Fareghi-Alamdari, Reza,Nadiri Niri, Mehri,Hazarkhani, Hassan,Zekri, Negar
p. 2615 - 2629
(2018/09/13)

A novel hydrogen-bonded silica-supported acidic ionic liquid: An efficient, recyclable and selective heterogeneous catalyst for the synthesis of diesters
Abstract: In this study, two novel acidic ionic liquids, including a hydroxyl functionalized diacidic ionic liquid [HFDAIL] and a sulfonated diacidic ionic liquid [SFDAIL], were prepared and immobilized on the surface of silica nanoparticles (SNPs) via hydrogen bonding. The materials were characterized by FT-IR, NMR, SEM, nitrogen physisorption measurement, TGA and acid-base titration. The catalytic activity of the prepared catalysts was investigated in the synthesis of phthalate, maleate and succinate diesters under solvent-free conditions. It was found that nanosilica@[HFDAIL] with higher availability of acidic sites and higher hydrophilicity was more efficient compared to the nanosilica@[SFDAIL]. Notably, nanosilica@[HFDAIL] catalyst has also demonstrated excellent selectivity for the diester product while the monoester product was predominant in the case of nanosilica@[SFDAIL] even after prolonged reaction time or higher catalyst loading. In addition, the nanosilica@[HFDAIL] catalyst could be separated by simple filtration and reused several times without any significant loss of catalytic performance, but a remarkable decrease in activity was observed for nanosilica@[SFDAIL] in the next runs. GRAPHICAL ABSTRACT?: SYNOPSIS Two novel acidic ionic liquids, including a hydroxyl functionalized diacidic ionic liquid [HFDAIL] and a sulfonated diacidic ionic liquid [SFDAIL], were prepared and immobilized on the surface of silica nanoparticles via hydrogen bonding. The catalytic activity of the catalysts was investigated in the synthesis of diesters under solvent-free conditions.
Fareghi-Alamdari, Reza,Niri, Mehri Nadiri,Hazarkhani, Hassan
(2018/05/28)

Ultrasound-assisted removal of Acid Red 17 using nanosized Fe3O4-loaded coffee waste hydrochar
The Fe3O4-loaded coffee waste hydrochar (Fe3O4-CHC) was synthesized using a simple precipitation method. The as-prepared adsorbent was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Fourier transform infrared spectroscopy (FT-IR). The EDX analysis indicated the presence of Fe in the structure of Fe3O4-CHC. The specific surface area of hydrochar increased from 17.2 to 34.7 m2/g after loading of Fe3O4 nanoparticles onto it. The prepared Fe3O4-CHC was used for removal of Acid Red 17 (AR17) through ultrasound-assisted process. The decolorization efficiency decreased from 100 to 74% with the increase in initial dye concentration and from 100 to 91 and 85% in the presence of NaCl and Na2SO4, respectively. The synthesized Fe3O4-CHC exhibited good stability in the repeated adsorption-desorption cycles. The high correlation coefficient (R2 = 0.997) obtained from Langmuir model indicated that physical and monolayer adsorption of dye molecules occurred on the Fe3O4-CHC surface. Furthermore, the by-products generated through the degradation of AR17 was identified by gas chromatography–mass spectrometry analysis.
Khataee, Alireza,Kayan, Berkant,Kalderis, Dimitrios,Karimi, Atefeh,Akay, Sema,Konsolakis, Michalis
p. 72 - 80
(2016/12/09)

Noncovalent Interactions in Ir-Catalyzed C-H Activation: L-Shaped Ligand for Para-Selective Borylation of Aromatic Esters
An efficient strategy for the para-selective borylation of aromatic esters is described. For achieving high para-selectivity, a new catalytic system has been developed modifying the core structure of the bipyridine. It has been proposed that the L-shaped ligand is essential to recognize the functionality of the oxygen atom of the ester carbonyl group via noncovalent interaction, which provides an unprecedented controlling factor for para-selective C-H activation/borylation.
Hoque, Md Emdadul,Bisht, Ranjana,Haldar, Chabush,Chattopadhyay, Buddhadeb
supporting information
p. 7745 - 7748
(2017/06/21)

Synthesis and characterization of a new hydroxyl functionalized diacidic ionic liquid as catalyst for the preparation of diester plasticizers
Two new functionalized diacidic ionic liquids (FDAILs) including hydroxyl functionalized diacidic ionic liquid (HFDAIL) and sulfonated diacidic ionic liquid (SFDAIL) were synthesized and characterized by 1HNMR, 13CNMR and FT-IR. The catalytic activities of these FDAILs were examined in esterification reaction of anhydrides with some alcohols to give corresponding dialkyl plasticizers under solvent-free conditions. The results indicate that HFDAIL, as hydroxyl-bearing catalyst, show better catalytic performance. Under the optimum conditions, using HFDAIL, the conversion of phthalic anhydride was high and diester plasticizers were obtained with good to excellent yields in the presence of only 10?mol% of ionic liquid. All the produced diesters could be easily recovered due to their immiscibility with the ionic liquid. Recycling experiments suggests that these ionic liquids can be reused several times without remarkable loss in their catalytic activity.
Fareghi-Alamdari, Reza,Nadiri Niri, Mehri,Hazarkhani, Hassan
p. 153 - 160
(2016/12/30)

Functionalized dicationic ionic liquids: Green and efficient alternatives for catalysts in phthalate plasticizers preparation
Two highly acidic, imidazolium-based, functionalized dicationic ionic liquids (FDCILs) were synthesized and characterized by FTIR, 1H NMR and13C NMR. The synthesized FDCILs were used as efficient and green catalysts in the synthesis of phthalate plasticizers through esterification of phthalic anhydride (PhA) with ethanol, n-propanol and n-butanol. Among these two FDCILs, (dimethyl-4-sulfobutyl-ammonium) 1,2-ethan-1-methyl-imidazolium-sulfonic acid hydrogen sulfate performed better. The catalytic activity of FDCIL is related to the density of acidic groups on it and the length of the carbon chain in the cationic part. The influences of the reaction temperature, catalyst dosage, and molar ratio of phthalic anhydride to alcohol on the esterification reaction were investigated. The reusability of the catalyst in these reactions was studied too. The diester phthalates were obtained up to 98.8% yield. The products can be separated easily by decantation from the reaction mixture. [Figure not available: see fulltext.]
Zekri, Negar,Fareghi-Alamdari, Reza,Khodarahmi, Zahra
p. 1277 - 1284
(2016/08/16)

Copper-Catalyzed Formal [4 + 1] Cycloaddition of Benzamides and Isonitriles via Directed C-H Cleavage
A copper-catalyzed formal [4 + 1] cycloaddition of benzamides and isonitriles via 8-aminoquinoline-directed C-H cleavage has been developed. The reaction proceeds well even in the presence of a base metal catalyst, CuBr·SMe2, alone to deliver the corresponding 3-iminoisoindolinones in good yields. Moreover, the unique acceleration effects of diphenyl sulfide are also disclosed.
Takamatsu, Kazutaka,Hirano, Koji,Miura, Masahiro
p. 4066 - 4069
(2015/09/01)

Palladium-Catalyzed Aerobic Oxidative Dehydrogenation of Cyclohexenes to Substituted Arene Derivatives
A palladium(II) catalyst system has been identified for aerobic dehydrogenation of substituted cyclohexenes to the corresponding arene derivatives. Use of sodium anthraquinone-2-sulfonate (AMS) as a cocatalyst enhances the product yields. A wide range of functional groups are tolerated in the reactions, and the scope and limitations of the method are described. The catalytic dehydrogenation of cyclohexenes is showcased in an efficient route to a phthalimide-based TRPA1 activity modulator.
Iosub, Andrei V.,Stahl, Shannon S.
supporting information
p. 3454 - 3457
(2015/03/30)

Transformation of amides into esters by the use of chlorotrimethylsilane
A mild transformation of various amides and imides into the corresponding esters and diesters in good yields by using chlorotrimethylsilane and alcohols at rt are described. Either primary, secondary, or tertiary amide or imide can be used in this transformation. Primary and secondary alcohols gave better yields than tertiary alcohols.
Xue, Cuihua,Luo, Fen-Tair
p. 359 - 362
(2015/02/02)

Sulfonated graphene as highly efficient and reusable acid carbocatalyst for the synthesis of ester plasticizers
Plasticizers are well known for their effectiveness in producing flexible plastics. The automotive, plastic and pharmaceutical industries, essential to a healthy economy, rely heavily on plasticizers to produce everything from construction materials to medical devices, cosmetics, children toys, food wraps, adhesives, paints, and 'wonder drugs'. Although H2SO4 is commonly used as commodity catalyst for plasticizer synthesis it is energy-inefficient, non-recyclable, and requires tedious separation from the homogeneous reaction mixture resulting in abundant non-recyclable acid waste. In this study, for the first time, we report an efficient synthesis of ester plasticizers (>90% yields) using sulfonated graphene (GSO3H) as an energy-efficient, water tolerant, reusable and highly active solid acid carbocatalyst. The hydrothermal sulfonation of reduced graphene oxide with fuming H2SO4 at 120°C for 3 days afforded GSO3H with remarkable acid activity as demonstrated by 31P magic-angle spinning (MAS) NMR spectroscopy. The superior catalytic performance of GSO3H over traditional homogeneous acids, Amberlyst-15, and acidic ionic liquids has been attributed to the presence of highly acidic and stable sulfonic acid groups within the two dimensional graphene domain, which synergistically work for high mass transfer in the reaction. Furthermore, the preliminary experimental results indicate that GSO3H is quite effective as a catalyst in the esterification of oleic and salicylic acid and thus may pave the way for its broad industrial applications in the near future.
Garg, Bhaskar,Bisht, Tanuja,Ling, Yong-Chien
p. 57297 - 57307
(2015/02/02)

Photolysis of methyl-parathion thin films: Products, kinetics and quantum yields under different atmospheric conditions
The present study focuses on the photodegradation of methyl-parathion thin films, an organophosphate insecticide, under different atmospheric conditions. The latter include nitrogenated, oxygenated and ozonated atmospheres, under low and high relative humidity conditions. Addition of oxygen to the atmospheric mixture did not seem to affect the reaction rates and quantum yields. Relative humidity affect was minor, with a small enhancement in reaction rate under 254. nm radiation. The addition of ozone (to either dry or humid atmosphere), at all concentrations tested, largely enhanced degradation rates. In the absence of ozone, the obtained quantum yields for photolysis of methyl-parathion thin films under 254 and 313. nm were 0.024 ± 0.007 and 0.012 ± 0.005, respectively. These values are higher than the values previously reported for solutions of methanol and water. Although the presence of molecular oxygen and water vapors did not seem to affect much the reaction rates, it did have a certain effect on the resulted products. More polar products were obtained under oxygenated and ozonated atmospheres, as well as dimers under ozone conditions. The reaction on thin films has yielded more toxic products than usually found in solutions, adding alkylphosphate esters in addition to the oxons formed normally.
Segal-Rosenheimer, Michal,Dubowski, Yael
scheme or table
p. 193 - 202
(2010/10/01)

Base-induced mechanistic variation in palladium-catalyzed carbonylation of aryl iodides
A mechanism, which is distinct from the traditional one when sodium alkoxide was used instead of tertiary amines, was proposed for the alkoxycarbonylation of aryl iodides. The catalytic cycle was composed of oxidative addition, subsequent ArPdOR formation, CO insertion to Pd-OR, and final reductive elimination of ArPdCOOR. The kinetic simultaneity of the formation of deiodinated side product from the aryl iodide and aldehyde from corresponding alcohol provided strong evidence for the existence of ArPdOR species. The observation of thioether, as the other competitive product in palladium catalyzed thiocarbonylation of aryl iodides and sodium alkylthiolate, also indicate the possibility of metathesis between ArPdl and sodium alkylthiolate. Preliminary kinetic studies revealed that neither oxidative addition nor reductive elimination was rate limiting. DFT calculation displayed preference for CO insertion into Pd-OR bond. The advantage of this novel mechanism had been demonstrated in the facile alkoxycarbonylation and thiocarbonylation. The ethoxycarbonylation of aryl iodides under room temperature and balloon pressure of CO in the presence of EtONa were examined, and good to high yields were obtained; the t-butoxycarbonylation reactions in the presence of t-BuONa were achieved, and the alkylthiocarbonylation (including the t-butylthiocarbonylation) of aryl iodides in the presence of sodium alkylthiolate were also investigated.
Hu, Yanhe,Liu, Jing,Lu, Zhixin,Luo, Xiancai,Zhang, Heng,Lan, Yu,Lei, Aiwen
supporting information; experimental part
p. 3153 - 3158
(2010/05/15)

DEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS TO RENDER THEM AVAILABLE FOR BIODEGRADATION
A method for the degradation of polycyclic aromatic compounds is disclosed that involves dissolving ozone in a bipolar solvent comprising a non-polar solvent in which is of sufficiently non-polar character to solubilized the polycyclic aromatic compounds, and a polar-water-compatible solvent which is fully miscible with the non-polar solvent to form a single phase with the non-polar solvent. The bipolar solvent with dissolved ozone is contacted with the polycyclic aromatic compounds to solubilize the polycyclic aromatic compounds and react the dissolved polycyclic aromatic compounds with the ozone to degrade the dissolved polycyclic aromatic compounds to oxygenated intermediates. The bipolar solvent is then mixed with sufficient water to form separate non-polar and polar phases, the non-polar phase comprising the non-polar solvent and the polar phase comprising the non-polar solvent and the oxygenated intermediates. The polar phase is then diluted and incubated with bacteria to biodegrade the oxygenated intermediates.
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Page/Page column 5-8; 15-16

(2008/12/07)

Palladium-catalyzed oxidative carbonylation of alkyl and aryl indium reagents with CO under mild conditions
CO now can react with organoindium reagents. A novel palladium-catalyzed oxidative carbonylation reaction of organoindium reagents by CO gas with desyl chloride as oxidant was developed in supplementation with the classical methods for preparation of carboxylic acid derivatives. Primary, secondary alkyl indium reagents with β-hydrogens and aryl indium reagents were suitable substrates, and the reaction could be carried out at 60°C under 50 psi CO. Carbonylation of alkyl indium reagents can occur smoothly without additional base. Although the indium reagents were prepared from corresponding Grignard reagents (at low temperature), they displayed full compatibility with various functional groups under the protic reaction conditions. Preliminary mechanistic studies including stoichiometric and catalytic reaction examination provided evidence to support the operation of the mechanism consisted of oxidative addition of deslyl chloride to Pd(0) and quick tautomerization to give a palladium enolate species II (ROPdCl), displacement of the enolate group in II by R2OH, followed by CO insertion to give alkoxycarbonyl palladium complex V, which undergoes transmetalation with R13ln and reductive elimination to afford the product and a Pd(0) species. In this mechanism, the alkoxycarbonyl group was transferred to the palladium center prior to the alkyl group, different from traditional ways initiated from oxidative addition of alkyl halides to a Pd(0) species.
Zhao, Yingsheng,Jin, Liqun,Li, Peng,Lei, Aiwen
supporting information; body text
p. 9429 - 9433
(2009/02/03)

Alkoxycarbonylation of aryl iodides catalyzed by Pd with a thiourea type ligand under balloon pressure of CO
Palladium-catalyzed alkoxycarbonylation of aryl iodides with a thiourea-oxazoline type ligand has been achieved under mild conditions. Various functional groups were tolerated and the yields were from moderate to excellent.
Liu, Jing,Liang, Bo,Shu, Dongxu,Hu, Yanhe,Yang, Zhen,Lei, Aiwen
p. 9581 - 9584
(2008/12/22)

Efficient esterification of carboxylic acids and phosphonic acids with trialkyl orthoacetate in ionic liquid
An operationally simple, inexpensive, efficient, and environmentally friendly esterification of various carboxylic acids, phosphonic acids, and phosphinic acids with triethyl orthoacetate or trimethyl orthoacetate under neutral conditions in a typical room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was successfully carried out to provide the corresponding ethyl esters or methyl esters in high yields.
Yoshino, Tomonori,Imori, Satomi,Togo, Hideo
p. 1309 - 1317
(2007/10/03)

Ozonolysis of enol ethers. Part 10. Ozonization of enol ethers from 1,2- and 1,3-dicarbonyl compounds: Direct quantitative synthesis of phthalonic acid anhydride
The results of ozonolyses of enol ethers from 1.2- and 1.3-dicarbonyl compounds presented here strongly indicate that these reactions do not proceed via the established Criegee ozonolysis mechanism for nucleophilic C=C bonds. The quantitative one-step synthesis of phthalonic acid anhydride via ozonolysis of 2-(methoxymethyliden)-1H-inden-1.3(2H)-dione (28a) is described. Furthermore, a revision of the theory of alkene ozonolysis in the presence of tetracyanoethylene (TCNE) is proposed on the basis of a single-electron-transfer (SET) chemistry.
Schank, Kurt,Beck, Horst,Pistorius, Susanne
p. 2025 - 2049
(2007/10/03)

Improvements in Diels-Alder cycloadditions with some acetylenic compounds under solvent-free microwave-assisted conditions: Experimental results and theoretical approaches
The Diels-Alder irreversible cycloadditions of 1,3-cyclohexadiene 1, 3-carbomethoxy-2-pyrone 2 and 2-methoxythiophene 3 with acetylenic dienophiles under solvent-free conditions are described. By strict comparisons with conventional heating under similar conditions, important specific microwave effects are revealed in the two last cases whereas they are absent in the first one. They are discussed in terms of asynchronous mechanisms in agreement with ab initio calculations at the HF/6-31G(d) level indicating dissymmetries in transition states. Specific MW effects can be understood by considering the enhancements in dipole moments from ground states to transition states.
Loupy, André,Maurel, Fran?ois,Sabatié-Gogová, Andrea
p. 1683 - 1691
(2007/10/03)

Transformation of amides into esters by the use of chlorotrimethylsilane
A mild transformation of various amides and imides into the corresponding esters and diesters in good yields by using chlorotrimethylsilane and alcohols at rt are described. Either primary, secondary, or tertiary amide or imide can be used in this transformation. Primary and secondary alcohols gave better yields than tertiary alcohols.
Xue, Cuihua,Luo, Fen-Tair
p. 359 - 362
(2007/10/03)

Unusual coupling reactions of aldehydes and alkynes: A novel preparation of substituted phthalic acid derivatives by automated synthesis
Based upon a highly versatile multicomponent methodology, a new one-pot synthesis of substituted phthalic acid derivatives from α,β-unsaturated aldehydes was developed. The reaction involves the intermediacy of an acetamidodiene species which undergoes Diels-Alder addition to diethyl acetylenedicarboxylate. The resultant acetamidocyclohexadiene is subject to elimination of acetamide under the reaction conditions to give rise to substituted diethyl phthalates in good yields. This domino condensation - cycloadditionelimination sequence has been applied to a variety of α,β-unsaturated aldehydes. Furthermore, we demonstrated the exploitation of parallelized and automated synthesis technology for the rapid screening of reaction conditions and compositions. Detailed studies revealed the catalytic role of the employed acetamide and the occurrence of a stereoselective 1,4-syn elimination pathway under standard conditions.
Von Wangelin, Axel Jacobi,Neumann, Helfried,Goerdes, Dirk,Klaus, Stefan,Jiao, Haijun,Spannenberg, Anke,Krueger, Thomas,Wendler, Christian,Thurow, Kerstin,Stoll, Norbert,Beller, Matthias
p. 2273 - 2281
(2007/10/03)

Cation-exchange resin-catalysed acylations and esterifications in fine chemical and perfumery industries
Acylation and esterification reactions are typically carried out by using homogeneous acids as catalysts which can be profitably replaced with heterogeneous solid acid catalysts to develop green chemistry. Solid acids that give the desired level of activity but which can be easily removed from the reaction mixture with no residual inorganic contamination of the organic products offer obvious advantages over existing methods. This contribution is concerned with eco-friendly synthesis of some commercially valuable products such as p-methoxyacetophenone, dimethyl phthalate, diethyl phthalate, methyl anthranilate, methyl salicylate, and methyl p-hydroxybenzoate (methyl paraben). The specifications require the esters to be free of halide impurities on ppm level for perfumery use, and thus use of chlorine-containing agents or catalysts must be avoided. The following catalysts were evaluated: Amberlyst-36, Bayer K2441, Amberlyst-15, Dowex 50Wx8, Indion-130, Deloxane ASP, Filtrol-24 clay, K-10 Montmorrilonite clay, and sulphated zirconia. Anisole was acylated with acetic anhydride to get 100% selectivity of p-methoxyacetophenone, and Amberlyst-36 was found to be the most active and reusable catalyst. A kinetic model is also presented. Amberlyst-36 was also the most active catalyst for the esterification reactions.
Yadav,Mujeebur Rahuman
p. 706 - 713
(2013/09/06)

Process for producing carboxylic acid esters and catalysts therefor
A process for producing carboxylic acid esters by the following steps: a) preparation of a reaction mixture containing an alcohol and a carboxylic acid and/or a carboxylic anhydride and/or a carboxylic acid ester and or a partially esterified carboxylic acid, b) heating of this mixture to the suitable reaction temperature in the presence of a solid polysiloxane insoluble in the reaction medium and having sulphonic acid groups with intensive thorough mixing accompanied by continuous separation of the reaction water which forms, wherein the polysiloxane used as the catalyst in modified by treatment with a soluble aluminum, titanium or zirconium compound, and the spherical particles thereof have a diameter of 0.01 to 3 mm, a specific surface of 0.1 to 1200 m2 /g, a specific pore volume of 0.01 to 6.0 ml/g and a bulk density of 50 to 1000 g/l.
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(2008/06/13)

A novel one-pot synthesis of esters by exchange reactions between carbonates and anhydrides
A new method for the synthesis of esters by exchange reaction between anhydrides and carbonates, without any solvent, in the presence of Ti or Sn based catalyst is presented.
Berti, Corrado,Colonna, Martino,Marianucci, Elisabetta,Sweileh, Bassam,Pilati, Francesco
p. 917 - 927
(2007/10/03)

Epimerization of 2- or 4- substituted cyclohexanecarboxylic acids
The present invention relates to a new method for obtaining a purity of about 93% to 100% of the trans form of 2- or 4-substituted cyclohexanecarboxylic acid or reactive derivatives thereof from the cis form or a mixture of the cis and trans forms by a single step, particularly, to a method for obtaining a purity of substantially 100% of the trans form of 4-substituted cyclohexanecarboxylic acid.
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(2008/06/13)

An efficient general method for esterification of aromatic carboxylic acids
Treatment of a variety of aromatic carboxylic acids with alcohols in the presence of thionyl chloride results in excellent yields of corresponding esters. This esterification system is compatible with a wide assortment of functional groups.
Hosangadi, Bhaskar D.,Dave, Rajesh H.
p. 6375 - 6378
(2007/10/03)

SYNTHESIS OF 1,2-DISUBSTITUTED BENZENES AND BIPHENYLS FROM PHTHALIC ACIDS THROUGH ELECTROREDUCTION FOLLOWED BY ELECTROCYCLIC REACTIONS WITH ALKYNES
Various substituted 1,2-dihydrophthalic acids were synthesized by electroreduction of phthalic acids in excellent yields.The electrocyclic reaction of 1,2-dihydrophthalic acids or the methyl ester with alkynes gave 1,2-disubstituted benzenes and biphenyls in good yields together with fumaric acid or methyl fumarate.
Ohno, Toshinobu,Ozaki, Masato,Inagaki, Atsuro,Hirashima, Tsuneaki,Nishiguchi, Ikuzo
p. 2629 - 2632
(2007/10/02)

CsF-Promoted Esterification of Carboxylic Acids. A Practical Alternative to the Diazomethane Method and Direct Conversion of Organotin Carboxylates
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Sato, Tsuneo,Otera, Junzo,Nozaki, Hitosi
p. 2166 - 2169
(2007/10/02)

Fragrance compositions and their use in detergent products
Compositions of fragrance materials having an Odour Intensity Index of less than 110, and a Malodour Reduction Value of at least 0.25 or an Odour Reduction Value of at least 0.25, can be used as fragrance compositions in detergent powders, detergent liquids, soap or detergent bars or pastes, fabric-conditioning compositions in liquid or solid form, or personal body deodorant compositions, to confer deodorant effects in use even though they have in themselves a low or imperceptible level of fragrance (Odour Intensity Index).
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(2008/06/13)

KINETICS OF THE REACTION OF SUPEROXIDE ANION-RADICAL WITH OLEFINS
Kinetic investigation of the reaction of electrochemically generated O2.- with perfluorooctene, styrene, and cyclohexene in acetonitrile, in the presence of tetraethylammonium perchlorate used as a background electrolyte, revealed that O2.- reacts with styrene and perfluorooctene at the double bond, and the reactivity of the olefins with respect to O2.- decreases with decrease in the electrophilicity of the substituents at the double bond: perfluorooctene > styrene > cyclohexene.The main transformation products of styrene are phthalic and benzoic acid esters.
Meskina, M. Ya.,Baider, L. M.,Skibida, I. P.
p. 646 - 650
(2007/10/02)

Solid-Liquid Phase-Transfer Catalysis without Added Solvent. A Simple, Efficient, and Inexpensive Synthesis of Aromatic Carboxylic Esters by Alkylation of Potassium Carboxylates
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Barry, J.,Bram, G.,Decodts, G.,Loupy, A.,Orange, C.,et al.
p. 40 - 45
(2007/10/02)

ALKYLATING PROPERTIES OF ALKYL PHOSPHITEDIETHYL AZODICARBOXYLATE REAGENT
Reaction of caoxylic acids, phenols, and some imides with phosphite esters in presence of diethyl azodicarboxylate result in transfer of an alkyl group from phosphite to a protic acid molecule In the case of enolizable C-H acids selective formation of O-alkylated products was observed.The reactions proceed under mild, virtually neutral conditions, affording good yields of alkylated products.
Grynkiewicz, Grzegorz
p. 149 - 152
(2007/10/02)