- Plastic crystalline lithium salt with solid-state ionic conductivity and high lithium transport number
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Plastic crystallinity of lithium salt, [LiB(OCH2CH 2OCH3)4] (1), and its solid-state ionic conductivity are disclosed. The addition of small amounts of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to borate 1 led to the drastic increase of the ionic conductivity and lithium transport number of the electrolyte.
- Moriya, Makoto,Kato, Daiki,Sakamoto, Wataru,Yogo, Toshinobu
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Read Online
- Participation by Ether Oxygen (RO-3) in the Hydrolysis of Sulfonate Esters of 2-Methoxyethanol and 2-Methoxy-2-methyl-1-propanol. Implications Regarding the Nonlinear Ethanol-Trifluoroethanol Plot for Mustard Chlorohydrin
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The lack of scrambling with deuterium-labeled reactants, a nonlinear ethanol-trifluoroethanol plot, and rate acceleration by edded thiourea are used to show that sulfonate esters of methoxyethanol (MeOCH2CH2OH) undergo solvent-assisted displacement in a variety of solvents; neighboring group participation by ether oxygen (RO-3 participation) does not occur.This conclusion is in accord with predictions of rate based on the Taft treatment of substituent effects.On the other hand, the branched derivative MeOCMe2CH2OBs reacts with concerted RO-3 participation to give completely rearranged product.It solvolysis rate is insensitive to added thiourea, the Taft treatment predicts modest anchimeric assistance, and a linear ethanol-trifluoroethanol plot is observed.We discuss the implications of these results relative to the previously observed nonlinear plot for mustard chlorohydrin.
- McManus, S. P.,Karman, R. M.,Sedaghat-Herati, R.,Neamati-Mazraeh, N.,Hovanes, B. A.,et al.
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- SN2 Displacement on 2-(Alkylthio)ethyl Derivatives
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We have studied the reaction mechanism of various 2-(alkylthio)ethyl and 2-(arylthio)ethyl derivatives with strong nucleophiles in an attempt to overcome powerful neighboring sulfur participation and shift reaction to a direct displacement SN2 mechanism.The 2,4-dinitrophenolate derivative of specifically deuteriated 2-(methylthio)ethanol reacts by an aromatic substitution mechanism (SNAr) when exposed to amines in aprotoc solvents.Use of sulfonate esters avoids competition from the SNAr mechanism.The rate of reaction of these esters in dimethyl sulfoxide (DMSO) or acetonitrile is independent of concentration of added methylamine, thiourea, urea, or iodide, thus indicating continued SN1 reaction with neighboring sulfur participation.Asd would be expected on this basis, but in contrast to previous mechanistic suggestions, the product for reaction with iodide in acetone shows complete scrambling of methylene groups.In contrast, reaction with thiophenolate ions in DMSO proceeds by direct nucleophilic displacement (an SN2 mechanism), as shown by second-order kinetics and unrearranged product.This is the first demonstration of SN2 displacement on a 2-(alkylthio)ethyl or 2-(arylthio)ethyl derivative.
- Herati-Sedaghat, M. R.,McManus, Samuel P.,Harris, J. Milton
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- A Simple, effective boron-halide ethoxylation catalyst
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Boron esters B(OR)3, readily derived from boric acid and alcohols, combine with iodide or bromide to catalyze the ethoxylation of alcohols and phenols, giving good rates and narrow product distributions. The combined action of a weak electrophile [B(OR)3] and a weak nucleophile (halide) allows for the ethoxylation of base-sensitive alcohols. Experiment suggests a new mechanism for this commercially important reaction proceeding through key β-haloalkoxy intermediates.
- Moloy, Kenneth G.
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- Hydrogen bonding lowers intrinsic nucleophilicity of solvated nucleophiles
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The relationship between nucleophilicity and the structure/environment of the nucleophile is of fundamental importance in organic chemistry. In this work, we have measured nucleophilicities of a series of substituted alkoxides in the gas phase. The functional group substitutions affect the nucleophiles through ion-dipole, ion-induced dipole interactions and through hydrogen bonding whenever structurally possible. This set of alkoxides serves as an ideal model system for studying nucleophiles under microsolvation settings. Marcus theory was applied to analyze the results. Using Marcus theory, we separate nucleophilicity into two independent components, an intrinsic nucleophilicity and a thermodynamic driving force determined solely by the overall reaction exothermicity. It is found that the apparent nucleophilicities of the substituted alkoxides are always much lower than those of the unsubstituted ones. However, ion-dipole, ion-induced dipole interactions, by themselves, do not significantly affect the intrinsic nucleophilicity; the decrease in the apparent nucleophilicity results from a weaker thermodynamic driving force. On the other hand, hydrogen bonding not only stabilizes the nucleophile but also increases the intrinsic barrier height by 3 to ～4 kcal mol-1. In this regard, the hydrogen bond is not acting as a perturbation in the sense of an external dipole but more directly affects the electronic structure and reactivity of the nucleophilic alkoxide. This finding offers a deeper insight into the solvation effect on nucleophilicity, such as the remarkably lower reactivities in nucleophilic substitution reactions in protic solvents than in aprotic solvents.
- Chen, Xin,Brauman, John I.
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- Selective synthesis of dimethoxyethane via directly catalytic etherification of crude ethylene glycol
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Etherification of ethylene glycol with methanol provides a sustainable route for the production of widely used dimethoxyethane; dimethoxyethane is a green solvent and reagent that is applied in batteries and used as a potential diesel fuel additive. SAPO-34 zeolite was found to be an efficient and highly selective catalyst for this etherification via a continuous flow experiment. It achieved up to 79.4% selectivity for dimethoxyethane with around 96.7% of conversion. The relationship of the catalyst's structure and the dimethoxyethane selectivity was established via control experiments. The results indicated that the pore structure of SAPO-34 effectively limited the formation of 1,4-dioxane from activated ethylene glycol, enhanced the reaction of the activated methanol with ethylene glycol in priority, and thus resulted in high selectivity for the desired products. The continuous flow technology used in the study could efficiently promote the complete etherification of EG with methanol to maintain high selectivity for dimethoxyethane.
- Yu, Weiqiang,Lu, Fang,Huang, Qianqian,Lu, Rui,Chen, Shuai,Xu, Jie
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Read Online
- Development of effective bidentate diphosphine ligands of ruthenium catalysts toward practical hydrogenation of carboxylic acids
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Hydrogenation of carboxylic acids (CAs) to alcohols represents one of the most ideal reduction methods for utilizing abundant CAs as alternative carbon and energy sources. However, systematic studies on the effects of metal-to-ligand relationships on the catalytic activity of metal complex catalysts are scarce. We previously demonstrated a rational methodology for CA hydrogenation, in which CA-derived cationic metal carboxylate [(PP)M(OCOR)]+ (M = Ru and Re; P = one P coordination) served as the catalyst prototype for CA self-induced CA hydrogenation. Herein, we report systematic trial- and-error studies on how we could achieve higher catalytic activity by modifying the structure of bidentate diphosphine (PP) ligands of molecular Ru catalysts. Carbon chains connecting two P atoms as well as Ar groups substituted on the P atoms of PP ligands were intensively varied, and the induction of active Ru catalysts from precatalyst Ru(acac)3 was surveyed extensively. As a result, the activity and durability of the (PP)Ru catalyst substantially increased compared to those of other molecular Ru catalyst systems, including our original Ru catalysts. The results validate our approach for improving the catalyst performance, which would benefit further advancement of CA self-induced CA hydrogenation.
- Saito, Susumu,Wen, Ke,Yoshioka, Shota
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p. 1510 - 1524
(2021/06/18)
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- Manganese catalyzed hydrogenation of carbamates and urea derivatives
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We report the hydrogenation of carbamates and urea derivatives, two of the most challenging carbonyl compounds to be hydrogenated, catalyzed for the first time by a complex of an earth-abundant metal. The hydrogenation reaction of these CO2-derived compounds, catalyzed by a manganese pincer complex, yields methanol in addition to amine and alcohol, which makes this methodology a sustainable alternative route for the conversion of CO2 to methanol, involving a base-metal catalyst. Moreover, the hydrogenation proceeds under mild pressure (20 bar). Our observations support a hydrogenation mechanism involving the Mn-H complex. A plausible catalytic cycle is proposed based on informative mechanistic experiments.
- Das, Uttam Kumar,Kumar, Amit,Ben-David, Yehoshoa,Iron, Mark A.,Milstein, David
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supporting information
p. 12962 - 12966
(2019/08/26)
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- Monomeric alkoxide and alkylcarbonate complexes of nickel and palladium stabilized with the iPrPCP pincer ligand: A model for the catalytic carboxylation of alcohols to alkyl carbonates
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Monomeric alkoxo complexes of the type [(iPrPCP)M-OR] (M = Ni or Pd; R = Me, Et, CH2CH2OH; iPrPCP = 2,6-bis(diisopropylphosphino)phenyl) react rapidly with CO2 to afford the corresponding alkylcarbonates [(iPrPCP)M-OCOOR]. We have investigated the reactions of these compounds as models for key steps of catalytic synthesis of organic carbonates from alcohols and CO2. The MOCO-OR linkage is kinetically labile, and readily exchanges the OR group with water or other alcohols (R′OH), to afford equilibrium mixtures containing ROH and [(iPrPCP)M-OCOOH] (bicarbonate) or [(iPrPCP)M-OCOOR′], respectively. However, [(iPrPCP)M-OCOOR] complexes are thermally stable and remain indefinitely stable in solution when these are kept in sealed vessels. The constants for the exchange equilibria have been interpreted, showing that CO2 insertion into M-O bonds is thermodynamically more favorable for M-OR than for M-OH. Alkylcarbonate complexes [(iPrPCP)M-OCOOR] fail to undergo nucleophilic attack by ROH to yield organic carbonates ROCOOR, either intermolecularly (using neat ROH solvent) or in intramolecular fashion (e.g., [(iPrPCP)M-OCOOCH2CH2OH]). In contrast, [(iPrPCP)M-OCOOMe] complexes react with a variety of electrophilic methylating reagents (MeX) to afford dimethylcarbonate and [(iPrPCP)M-X]. The reaction rates increase in the order X = OTs IMe ? OTf and Ni Pd. These findings suggest that a suitable catalyst design should combine basic and electrophilic alcohol activation sites in order to perform alkyl carbonate syntheses via direct alcohol carboxylation.
- Martínez-Prieto, Luis M.,Palma, Pilar,Cámpora, Juan
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p. 1351 - 1366
(2019/01/30)
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- Influence of Boiling on the Radiolysis of Diglyme
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The radiolysis of diethylene glycol dimethyl ether (diglyme) in a boiling state has been studied for the first time. Boiling facilitates the cleavage of internal C–O bonds, weakens the cage effect and diglyme regeneration processes, and facilitates the exchange and dimerization reactions of radicals. As compared with radiolysis at room temperature, the amount of unsaturated products of diglyme fragmentation formed during irradiation in the boiling state is smaller by a factor of 4, and the disproportionation products of heavy radicals are found in negligible amounts, if any. The yield of radiolytic decomposition of diglyme under boiling conditions is ～15 molecule/100 eV, which is higher than that at room temperature by a factor of almost 1.5.
- Vlasov,Kholodkova,Ponomarev
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p. 312 - 318
(2018/08/01)
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- Bipyridine ligand ruthenium complex is carried and its preparation method and application (by machine translation)
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The invention relates to a novel bipyridine is carried ligand ruthenium complex and its preparation method and in the ester compound hydrogenation is the application of the alcohol compound in the reaction. The use of the bipyridine ligand ruthenium complex catalytic hydrogenation is carried ester compound alcohol compound method is characterized in that: in order to ester compound material in an amount of 0.001 - 0.3 μM % bipyridyl is carried ligand ruthenium complex as catalyst, adding esters compound material in an amount of 1 - 10mol % alkali, in the 25 - 100 °C and 1 - 10MPa hydrogen pressure catalytic hydrogenation under the conditions of ester compound corresponding alcohol compound. The invention of the bipyridine ligand ruthenium complex is carried is convenient to prepare, stable structure, in the ester compound in hydrogenation reaction exhibits excellent catalytic activity. This invention has overcome the ester compound or a non-homogeneous phase catalytic hydrogenation system requires high-temperature high-pressure reaction conditions and high defects of the catalyst amount, catalyst consumption is small, mild reaction conditions, the reaction selectivity is good, improves the economy and the safety of the production system. (by machine translation)
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Paragraph 0098; 0099; 0100; 0102; 0104
(2017/04/28)
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- Immobilization of Carbonylcobalt Catalyst by Poly(4-vinylpyridine) (P4VP) through N→Co Coordination Bonds: The Promotional Effect of Pyridine and the Reusability of Polymer Catalyst
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A carbonylcobalt catalyst, immobilized by poly(4-vinylpyridine) (P4VP) through N→Co coordination bonds, has been prepared by solvothermal method. It has been revealed that the pyridine fragments in the polymer catalyst act not only as promoters to improve the catalytic performance of the carbonylcobalt catalyst for alkoxycarbonylation of ethylene oxide to methyl 3-hydroxypropanoate but also as stabilizers to enhance the reusability of the polymer catalyst. Furthermore, the polymer catalyst could be easily separated by filtration and reused with only a slight loss of catalytic efficiency.
- Liu, Yu-Bing,Wang, Yi-Ning,Lu, Hai-Meng,Liang, Shuang,Xu, Bo-Lian,Fan, Yi-Ning
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supporting information
p. 3159 - 3164
(2016/11/29)
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- Vanadium-Catalyzed Oxidative Debenzylation of O-Benzyl Ethers at ppm Level
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An advantageous methodology for the oxidative debenzylation of ethers has been developed. Very low amounts of a catalyst system based on vanadyl acetylacetonate and a triazole type pincer ligand allow the selective oxidative cleavage of a number of O-benzyl ethers in the presence of oxygen as the sole oxidant. The methodology tolerates a number of functional groups such as halo-, alkoxy-, or trifluoromethylarenes, alkyne, alkene, ether, and acetal units. Large-scale deprotections can be also carried out by the optimized procedure, which is amenable to enantioenriched reactants as well. (Figure presented.).
- Urgoitia, Garazi,SanMartin, Raul,Herrero, María Teresa,Domínguez, Esther
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p. 3307 - 3312
(2016/10/21)
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- Selective synthesis of ethylene oxide through liquid-phase epoxidation of ethylene with titanosilicate/H2O2 catalytic systems
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Liquid-phase epoxidation of ethylene to ethylene oxide (EO) with H2O2 over various titanosilicate catalysts like Ti-MWW, TS-1, Ti-MOR and Ti-Beta has been investigated. The effects of solvent, catalyst amount, reaction pressure, temperature and time on the catalytic performance of Ti-MWW have been studied in detail. Ti-MWW preferred acetonitrile as a solvent and showed the highest reactivity and EO selectivity among the titanosilicate catalysts investigated. Under optimized reaction conditions, Ti-MWW gave a EO selectivity high as 97.9% as well as a reasonable utilization efficiency of H2O2 of 77.7%. Ti-MWW was gradually deactivated after repeated use in ethylene epoxidation. High-temperature calcination easily recovered the catalytic activity of deactivated Ti-MWW after removing ethylene glycol (EG) and other heavy byproducts with high boiling points that were deposited inside micropores. The issues of molecular dimension and reactivity have also been considered by comparing the epoxidation of linear alkenes with different lengths (C2 to C6) between two representative titanosilicates Ti-MWW and TS-1. Ethylene, with the smallest dynamic diameter but containing electron-deficient C=C double bonds, was more difficult to be epoxidized than other alkenes with higher intrinsic activities.
- Lu, Xinqing,Zhou, Wen-Juan,Wu, Haihong,Liebens, Armin,Wu, Peng
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- Selective hydrogenation of lactic acid to 1,2-propanediol over highly active ruthenium-molybdenum oxide catalysts
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Modification of Ru/C with a small amount of MoOx (Ru-MoOx/C) enhanced the catalytic activity in the hydrogenation of L-lactic acid to form 1,2-propanediol and maintained high selectivity. The turnover frequency based on the amount of Ru over the optimized Ru-MoOx/C catalyst (Mo/Ru molar ratio=1:16) was 114 h-1 at 393 K, which was about 4 times higher than that over Ru/C. The same effect of MoOx was obtained over Ru-MoOx/SiO2, although Ru-MoOx/SiO2 showed slightly lower activity than that of Ru-MoOx/C. Ru-MoOx/C achieved a high yield of 95 % in 18 h at 393 K and was applicable to various carboxylic acids to provide the corresponding alcohols in high yields. Modification with MoOx also brought about suppression of racemization and (S)-1,2-propanediol was obtained in high enantiomeric excess at 353 K. Based on kinetic analysis and characterization data, such as XRD, TEM, CO adsorption by a volumetric method, FTIR spectroscopy, and X-ray absorption spectroscopy, for Ru-MoOx/C and Ru-MoOx/SiO2, the catalyst structure and reaction mechanism are proposed.
- Takeda, Yasuyuki,Shoji, Tomohiro,Watanabe, Hideo,Tamura, Masazumi,Nakagawa, Yoshinao,Okumura, Kazu,Tomishige, Keiichi
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p. 1170 - 1178
(2015/04/22)
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- Ruthenium complexes of tetradentate bipyridine ligands: Highly efficient catalysts for the hydrogenation of carboxylic esters and lactones
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A new type of readily available, air-stable ruthenium complex of tetradentate bipyridine ligands has been developed. These complexes displayed exceptional efficiency for the hydrogenation of aromatic and aliphatic carboxylic esters and lactones at as low as 10 ppm catalyst loading under very mild conditions. the Partner Organisations 2014.
- Li, Wei,Xie, Jian-Hua,Yuan, Ming-Lei,Zhou, Qi-Lin
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supporting information
p. 4081 - 4085
(2014/10/15)
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- Highly selective one-pot continuous synthesis of 2-methoxyethanol via hydrogenation of dimethyl oxalate on Cu/ZrO2 catalysts with balanced acid sites
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The distribution of 2-methoxyethanol and ethylene glycol can be controlled by regulating the surface acidity of copper based zirconia catalysts for hydrogenation of dimethyl oxalate. The yield of 2-methoxyethanol can reach 68% due to the synergistic effec
- Cui, Yuanyuan,Wen, Chao,Chen, Xi,Dai, Wei-Lin
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p. 31162 - 31165
(2014/08/05)
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- Unprecedented iron-catalyzed ester hydrogenation. Mild, selective, and efficient hydrogenation of trifluoroacetic esters to alcohols catalyzed by an iron pincer complex
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The synthetically important, environmentally benign hydrogenation of esters to alcohols has been accomplished in recent years only with precious-metal-based catalysts. Here we present the first iron-catalyzed hydrogenation of esters to the corresponding alcohols, proceeding selectively and efficiently in the presence of an iron pincer catalyst under remarkably mild conditions. The replacement of precious-metal catalysts by an iron complex was accomplished for the synthetically important, environmentally benign hydrogenation of esters to alcohols under mild conditions. The iron pincer complex (see scheme) selectively and efficiently catalyzes the hydrogenation of trifluoroacetates under remarkably mild conditions (5-25 bar and 40 °C).
- Zell, Thomas,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 4685 - 4689
(2014/05/20)
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- A procedure for the preparation of Ti-Beta zeolites for catalytic epoxidation with hydrogen peroxide
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Ti-Beta zeolite has been successfully prepared via a reproducible and scalable two-step post-synthesis strategy, which consists of creating vacant T sites with associated silanol groups by dealumination of H-Beta and subsequent dry impregnation of the resulting Si-Beta with titanocene dichloride. The mechanism of Ti incorporation into the framework of Beta is investigated by diffuse reflectance infrared Fourier transform (DRIFT) and multinuclear solid-state nuclear magnetic resonance (SSNMR) spectroscopy. Characterization results obtained from diffuse reflectance ultraviolet-visible (UV-vis) and X-ray photoelectron spectroscopy (XPS) reveal that the majority of incorporated Ti species exist in the form of isolated tetrahedrally coordinated Ti(iv) in the zeolite framework while a minority exists in the form of isolated octahedrally coordinated Ti(vi) at framework or extra-framework positions. The obtained Ti-Beta zeolites are highly active and selective catalysts for the epoxidation of unsaturated ketones, e.g. 2-cyclohexen-1-one, with hydrogen peroxide as an oxidant. A quasilinear correlation between the epoxidation rate and the number of framework Ti(iv) species could be drawn evidencing that these Ti(iv) species are responsible for the epoxidation activity of the Ti-Beta zeolites under study. The impact of preparation parameters and reaction conditions on the catalytic performances of the Ti-Beta zeolites in the epoxidation of unsaturated organic compounds with hydrogen peroxide is discussed in detail. the Partner Organisations 2014.
- Tang, Bo,Dai, Weili,Sun, Xiaoming,Guan, Naijia,Li, Landong,Hunger, Michael
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p. 2281 - 2291
(2014/04/17)
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- Replacing phosphorus with sulfur for the efficient hydrogenation of esters
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Catalyst tune-up: A readily available, air-stable amino-sulfide catalyst, [RuCl2(PPh3){HN(C2H4SEt) 2}], has been developed. This complex displays outstanding efficiency for the hydrogenation of a broad range of substrates with C-X bonds (esters, ketones, imines), as well as for the acceptorless dehydrogenative coupling of ethanol to ethyl acetate (see scheme). Copyright
- Spasyuk, Denis,Smith, Samantha,Gusev, Dmitry G.
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supporting information
p. 2538 - 2542
(2013/04/10)
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- COMPOSITIONS, SYNTHESIS, AND METHODS OF USING PHENYLCYCLOALKYLMETHYLAMINE DERIVATIVES
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The present invention provides novel phenylcycloalkylmethylamme derivatives, and methods of preparing phenylcycloalkylmethylamme derivatives. The present invention also provides methods of using phenylcycloalkylmethylamme derivatives and compositions of phenylcycloalkylmethylamme derivatives. The pharmaceutical compositions of the compounds of the present invention can be used for treating and/or preventing obesity and obesity related co- morbid indications and depression and depression related co-morbid indications.
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Page/Page column 54
(2013/07/19)
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- The ammonolysis of esters in liquid ammonia
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The rates of ammonolysis of alkyl benzoate and phenylacetate esters in liquid ammonia increase with the acidity of the leaving group alcohol and show relatively large Bronsted βlg values of -1.18 and -1.34, respectively, when plotted against the aqueous pKa of the alcohol. The Bronsted βlg obtained using the pKa of the leaving group alcohol in liquid ammonia is significantly reduced to ~ -0.7, which indicates that the rate-limiting step involves a reaction of the tetrahedral intermediate with little C-OR bond fission in the transition state. The solvolysis reaction is subject to significant catalysis by ammonium ion, which, surprisingly, generates a similar Bronsted βlg indicating little interaction between the ammonium ion and the leaving group. It is concluded that the rate-limiting step for the ammonium-ion-catalysed solvolysis of alkyl esters in liquid ammonia is the diffusion-controlled protonation of the zwitterionic tetrahedral intermediate T+- to give T+, which is rapidly deprotonated to give T0 which is compatible with the rate-limiting step for the uncatalysed reaction being the formation of the neutral T0 by a 'proton switch'. Copyright 2013 John Wiley & Sons, Ltd. The rates of ammonolysis of alkyl benzoate and phenylacetate esters in liquid ammonia increase with the acidity of the leaving group alcohol and show relatively large Bronsted βlg values of -1.18 and -1.34, respectively, when plotted against the aqueous pKa of the alcohol. The Bronsted βlg obtained using the pKa of the leaving group alcohol in liquid ammonia is significantly reduced to ~ -0.7, which is compatible with the rate limiting step for the uncatalysed reaction being the formation of the neutral T0 by a 'proton switch'. Copyright
- Griffin, Joseph,Atherton, John,Page, Michael I.
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p. 1032 - 1037
(2014/01/06)
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- Highly selective synthesis of ethylene glycol and ethanol via hydrogenation of dimethyl oxalate on Cu catalysts: Influence of support
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The catalytic performances of co-precipitated copper catalysts supported on SiO2, ZrO2 and Al2O3 for dimethyl oxalate hydrogenation were studied. Systematic characterizations showed that copper species formed on different supports as a result of different metal-support interactions influenced the activity and stability, while the nature of supports was closely related to the products distribution in dimethyl oxalate hydrogenation. Mainly large Cu particles were detected over Cu/SiO 2 catalyst which exhibited a low activity and stability. For the Cu/ZrO2 catalyst, the highly dispersed Cu particles and the strong metal-support interaction are in favor of its superior activity and stability. Among the catalysts, Cu/SiO2 exhibited maximum ethylene glycol selectivity while Cu/Al2O3 showed a 2-methoxyethanol selectivity of 53.5% in methanol solvent. As tuning the solvent into 1,4-dioxane, an ethanol yield up to 95.5% was received in Cu/Al 2O3. The significant difference of selectivity is mainly due to the acidity of the catalysts. Thus, the highly selective synthesis of ethylene glycol and ethanol could be realized by regulating the supports and solvents, and a proper reaction route was proposed.
- Zhu, Yulei,Zhu, Yifeng,Ding, Guoqiang,Zhu, Shanhui,Zheng, Hongyan,Li, Yongwang
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p. 296 - 304
(2013/10/22)
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- Direct deamination of primary amines by water to produce alcohols
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Just add water! The title reaction is catalyzed by an acridine-based pincer complex (1, see scheme). This one-step transformation uses water as the only reagent in the absence of additional bases, oxidants, or reductants. Cyclization of 1,4-diaminobutane and 1,6-diaminohexane catalyzed by 1 leads to the formation of pyrrolidine and azepane, respectively. Copyright
- Khusnutdinova, Julia R.,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 6269 - 6272
(2013/07/19)
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- Acceptorless dehydrogenative coupling of ethanol and hydrogenation of esters and imines
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This paper presents an outstanding air-stable ruthenium catalyst that has unprecedented efficiency (TON up to 17-000) for acceptorless dehydrogenative coupling of ethanol, yielding ethyl acetate and hydrogen gas, and for hydrogenation of esters and imines at 40 °C while using as low as 50 ppm [Ru].
- Spasyuk, Denis,Gusev, Dmitry G.
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p. 5239 - 5242,4
(2020/08/31)
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- NOVEL RUTHENIUM CARBONYL COMPLEX HAVING TRIDENTATE LIGAND, ITS PRODUCTION METHOD AND USE
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The present invention relates to a ruthenium carbonyl complex that is represented by the following Formula (1): [in-line-formulae]RuXY(CO)(L)??(1)[/in-line-formulae](in the Formula (1), X and Y, which may be the same or different from each other, represent an anionic ligand and L represents a tridentate aminodiphosphine ligand which has two phosphino groups and a —NH— group), its production method, and a method for production of alcohols by hydrogenation-reduction of ketones, esters, and lactones using the complex as a catalyst. The ruthenium carbonyl complex of the invention has a high catalytic activity and it can be easily prepared and handled.
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Page/Page column 17
(2011/10/12)
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- Quaternary ammonium ionic liquids as Bi-functional catalysts for one-step synthesis of dimethyl carbonate from ethylene oxide, carbon dioxide and methanol
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One kind of novel ionic liquids (ILs) with a tertiary amino moiety and a quaternary ammonium group were synthesized and identified by FT-IR, 1H and 13C NMR. The elemental chemical state and basicity of ILs were determined by XPS and Hammett indicator method, respectively. Then the catalytic performance of these bi-functional catalysts was investigated in one-step synthesis of dimethyl carbonate (DMC) from ethylene oxide (EO), carbon dioxide and methanol. The best catalytic performance with 99% EO conversion and a maximum of 74% DMC selectivity was obtained using [N111,6N11]I as catalyst under optimized reaction conditions. And the catalyst could be reused for several times. Normally, stronger basicity could be obtained by altering the anions with different nucleophilicity in ILs and a better catalytic activity could be achieved correspondingly. A mechanism that both the ring opening of epoxide through nucleophilic attacks and the transesterification play an important role in the reaction was proposed based on experimental results.
- Li, Jian,Wang, Liguo,Shi, Feng,Liu, Shimin,He, Yude,Lu, Liujin,Ma, Xiangyuan,Deng, Youquan
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experimental part
p. 339 - 346
(2011/12/22)
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- Synthesis of sulfonic acid functionalized carbon catalyst from glycerol pitch and its application for tetrahydropyranyl protection/deprotection of alcohols and phenols
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A novel carbon catalyst with -SO3H, -OH and -COOH functional groups was prepared from glycerol pitch by in situ partial carbonization and sulfonation with sulfuric acid. The activity of the catalyst was investigated through tetrahydropyranylation and dehydropyranylation of a wide variety of alcohols and phenols at room temperature by changing the solvent medium from dichloromethane to methanol. Excellent yields, short reaction times, easy and quick isolation of the products and reusability of the catalyst are the main attractions of this method. The novel carbon catalyst holds great potential in the green chemical processes.
- Prabhavathi Devi,Gangadhar,Siva Kumar,Shiva Shanker,Prasad,Sai Prasad
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experimental part
p. 96 - 100
(2011/10/05)
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- Further insights into the chemistry of niobium and tantalum pentahalides with 1,2-dialkoxyalkanes: Synthesis of bromo- and iodoalkoxides, spectroscopic and computational studies
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The room temperature reactions of a series of 1,2-dialkoxyalkanes ROCH 2CH(R′)OR′′ with MX5 (M = Nb, Ta; X = Br, I) in 1:1 ratio result in single C-O bond cleavage and high-yield formation of the halo-alkoxides MBr4[κ2-OCH 2CH(R′)OR′′] or [NbI4{κ 1-OCH2CH(R′)OR′′}]2, and equimolar amounts of the corresponding alkyl halides RX. The reaction of NbBr5 with 1,2-dimethoxyethane, dme, proceeds with preliminary formation of the ionic species [NbBr4(κ2-dme) (κ1-dme)][NbBr6], 3b, which has been identified by solution NMR at low temperature and conductivity analyses. The gas-phase structure of 3b has been optimized by DFT calculations, confirming that the dme ligands adopt bidentate and monodentate coordination, respectively. Although the formation of NbOBr3(dme), 4b, 1,4-dioxane and MeBr from NbBr 5/dme (ratio 1:2) is an exoergonic process (calculated ΔGr° = -115.96 kcal mol-1), it is inhibited at room temperature. High temperature conditions enhance the production of 1,4-dioxane at the expense of selectivity. The dinuclear species NbOBr3(dme)NbBr5 (Nb-O-Nb), 5b, (X-ray) has been isolated in modest yield as byproduct of the room temperature reaction of NbBr5 with dme. In general, the 1:2 molar reactions of NbX5 (X = Br, I) with ROCH2CH(R′) OR′′ occur with the exclusion of nearly one equivalent of organic reactant.
- Bini, Riccardo,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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experimental part
p. 1412 - 1419
(2011/06/22)
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- METHOD FOR PRODUCING AN AMINE
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Processes for preparing an amine, which processes comprise: reacting a reactant selected from the group consisting of primary alcohols, secondary alcohols, aldehydes, ketones, and mixtures thereof, with hydrogen and a nitrogen compound selected from the group consisting of ammonia, primary amines, secondary amines and mixtures thereof, in the presence of a zirconium dioxide-, copper- and nickel-containing catalyst; wherein the catalyst comprises a catalytically active composition which comprises, before reduction with hydrogen, oxygen compounds of zirconium, copper, nickel and tin, and 0.5 to 8.0% by weight of an oxygen compound of cobalt, calculated as CoO, and wherein the catalytically active composition does not comprise any ruthenium.
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Page/Page column 11
(2011/04/14)
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- Direct hydrogenation of amides to alcohols and amines under mild conditions
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The selective, direct hydrogenation of amides to the corresponding alcohols and amines with cleavage of the C-N bond was discovered. The expected products of C-O cleavage are not formed (except as traces in the case of anilides). The reaction proceeds under mild pressure and neutral, homogeneous conditions using a dearomatized, bipyridyl-based PNN Ru(II) pincer complex as a catalyst. The postulated mechanism involves metal-ligand cooperation by aromatization- dearomatization of the heteroaromatic pincer core and does not involve hydrolytic cleavage of the amide. The simplicity, generality, and efficiency of this environmentally benign process make it attractive for the direct transformations of amides to alcohols and amines in good to excellent yields.
- Balaraman, Ekambaram,Gnanaprakasam, Boopathy,Shimon, Linda J. W.,Milstein, David
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supporting information; experimental part
p. 16756 - 16758
(2011/02/16)
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- Ferric perchlorate as an efficient and useful catalyst for the selective benzylation and methylation of alcohols with benzyl chloride and methyl iodide
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A mild and efficient method was developed for selective benzylation and methylation of hydroxyl compounds in the presence of a catalytic amount of ferric perchlorate. We showed that ferric perchlorate was very effective in selectively promoting the benzylation and methylation of primary aliphatic and benzylic alcohols versus secondary aliphatic alcohols and phenolic hydroxy groups. Graphical abstract: [Figure not available: see fulltext.]
- Behbahani, Farahnaz K.,Heravi, Majid M.,Oskooie, Hossien A.
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experimental part
p. 181 - 184
(2010/03/26)
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- Bacillus subtilis esterase (BS2) and its double mutant have different selectivity in the removal of carboxyl protecting groups
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An esterase from Bacillus subtilis (BS2) and its double mutant E188W/M193C quickly hydrolyze n-butyl, n-propyl, methoxyethyl and allyl esters. The wild-type BS2 preferentially removes such esters from the y-position of glutamate diesters, while the engineered enzyme has a reversed selectivity removing esters from the a-position of glutamate diesters. Automated docking and molecular dynamic simulations were performed to understand the molecular reason for the different regioselectivity.
- Barbayianni, Efrosini,Kokotos, Christoforos G.,Bartsch, Sebastian,Drakou, Christina,Bornscheuer, Uwe T.,Kokotos, George
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scheme or table
p. 2325 - 2332
(2009/12/28)
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- Methods for preparing 3-hydroxy-propionate and 1,3-propylene glycol
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The invention disclosed a method for producing 3-hydroxy-propionate and 1,3-propylene glycol by using epoxide as raw material. In the method, a transitional metal cobalt catalyst and a cocatalyst for the hydroesterification reaction among epoxide, carbon monoxide, and alcohol were chosen, and a hydrogenation catalyst for hydrogenating 3-hydroxy-propionate as well as the corresponding process conditions were selected for producing 3-hydroxy-propionate and 1,3-propylene glycol.
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Page/Page column 3-4
(2008/06/13)
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- Production of catalyst
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Disclosed are catalysts, the catalytically active mass of which contains 22 to 40 percent by weight of oxygen-containing compounds of zirconium, calculated as ZrO2, 1 to 30 percent by weight of oxygen-containing compounds of copper, calculated as CuO, 15 to 50 percent by weight of oxygen-containing compounds of nickel, calculated as NiO, the molar ratio between nickel and copper being greater than 1, 15 to 50 percent by weight of oxygen-containing compounds of cobalt, calculated as CoO, and less than 1 percent by weight of an alkali metal, calculated as alkali metal oxide, prior to being treated with hydrogen. Also disclosed is a method for the production of amines by reacting primary and secondary alcohols, aldehydes, or ketones with hydrogen and nitrogen compounds selected from the group ammonia, primary and secondary amines, in the presence of said catalysts at an elevated temperature and an elevated pressure.
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Page/Page column 19; 22
(2008/06/13)
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- Kinetic solvent deuterium isotope effect in transesterification of RNA models
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2-Methylbenzimidazole ribonucleoside arylphosphates (1a,b) and alkylphosphates (2a,b) were synthesized as RNA model compounds containing a minimised number of exchangeable protons. Intramolecular transesterification of these substrates was studied in H2O and D2O solutions over a wide pL range and apparent kinetic solvent deuterium isotope effects of the alkaline cleavage of both substrates and of the cleavage and isomerisation of 2a under neutral and acidic conditions were determined. The observed K H2O/kD2O of 4.9 obtained for the alkaline cleavage of the arylphosphate 1b can be primarily attributed to the ΔpK of the attacking nucleophile. The alkyl leaving group in 2a brings about an additional 1.5-fold isotope effect (kH2O/kD2O of 7.1 observed), which, considering the pL-dependence of the reaction, can not be explained by a process involving a proton transfer. Differences in solvation of the transition state are tentatively suggested as a source of the difference. In contrast to alkaline cleavage, under neutral and acidic conditions the cleavage and isomerisation of 2a showed no apparent solvent isotope effect. Several examples found in the literature show that intramolecular proton transfer from phosphate to the leaving group in pre-equilibria may not necessarily result in an observable solvent isotope effect. This may also explain the results obtained in the present work, since intramolecular proton transfer processes take place in transesterification reactions of 2a under neutral and acidic conditions. Relevance of the results obtained in the base catalysed cleavage to hammerhead ribozyme reaction is briefly discussed. Copyright
- Virtanen, Noora,Polari, Lauri,Vaelilae, Maria,Mikkola, Satu
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p. 385 - 397
(2007/10/03)
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- Calcitonin drug-oligomer conjugates, and uses thereof
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Calcitonin drug-oligomer conjugates that include a calcitonin drug coupled to an oligomer including a single polyalkylene glycol moiety consisting of between 4 and 10 polyalkylene glycol subunits are disclosed. Pharmaceutical compositions including such conjugates and methods of treating bone disorders by administering such conjugates are also disclosed.
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- METHOD OF PRODUCING GLYCOL ETHERS
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The present invention provides a method of producing glycol ethers, which are also commonly known as glymes. The method according to the invention includes contacting a glycol with a monohydric alcohol in the presence of a polyperfluorosulfonic acid resin catalyst under conditions effective to produce the glyme. The method of the invention can be used to produce, for example, monoglyme, ethyl glyme, diglyme, ethyl diglyme, triglyme, butyl diglyme, tetraglyme, and their respective corresponding monoalkyl ethers. The present invention also provides a method of producing 1,4-dioxane from mono- or diethylene glycol and tetrahydrofuran from 1,4-butanediol.
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- Continuous chemoselective methylation of functionalized amines and diols with supercritical methanol over solid acid and acid-base bifunctional catalysts
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The selective N-methylation of bifunctionalized amines with supercritical methanol (scCH3OH) promoted by the conventional solid acids (H-mordenite, β-zeolite, amorphous silica-alumina) and acid-base bifunctional catalysts (Cs-P-Si mixed oxide and γ-alumina) was investigated in a continuous-flow, fixed-bed reactor. The use of scCH 3OH in the reaction of 2-aminoethanol with methanol (amine/CH 3OH = 1/10.8) over the solid catalysts led to a significant improvement in the chemoselectivity of the N-methylation. Among the catalysts examined, the Cs-P-Si mixed oxide provided the most efficient catalyst performance in terms of selectivity and reactivity at 300 °C and 8.2 MPa; the N-methylation selectivity in the products reaching up to 94% at 86% conversion. The present selective methylation was successfully applied to the synthesis of N-methylated amino alcohols and diamines as well as O-methylated ethylene glycol. Noticeably, ethoxyethylamine was less reactive, suggesting that the hydroxy group of the amino alcohols is a crucial structural factor in determining high reactivity and selectivity, possibly because of the tethering effect of another terminus, a hydroxo group, to the catalyst surface. The magic-angle-spinning NMR spectroscopy and X-ray diffraction analysis of the Cs-P-Si mixed oxide catalyst revealed that the acidic and basic sites originate from P2O5/SiO2 and Cs/SiO2, respectively, and the weak acid-base paired sites are attributed to three kinds of cesium phosphates on SiO2. The weak acid-base sites on the catalyst surface might be responsible for the selective dehydrative methylation.
- Oku, Tomoharu,Arita, Yoshitaka,Tsuneki, Hideaki,Ikariya, Takao
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p. 7368 - 7377
(2007/10/03)
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- Mixtures of growth hormone drug-oligomer conjugates comprising polyalkylene glycol, uses thereof, and methods of making same
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A mixture of conjugates in which each conjugate in the mixture comprises a growth hormone drug coupled to an oligomer that includes a polyalkylene glycol moiety is disclosed.
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- Mixtures of insulin drug-oligomer conjugates comprising polyalkylene glycol, uses thereof, and methods of making same
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A mixture of conjugates in which each conjugate in the mixture comprises an insulin drug coupled to an oligomer that includes a polyalkylene glycol moiety is disclosed. The mixture may exhibit higher in vivo activity than a polydispersed mixture of similar conjugates. The mixture may also be more effective at surviving an in vitro model of intestinal digestion than polydispersed mixtures of similar conjugates. The mixture may also result in less inter-subject variability than polydispersed mixtures of similar conjugates.
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- Mixtures of calcitonin drug-oligomer conjugates comprising polyalkylene glycol, uses thereof, and methods of making same
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A mixture of conjugates in which each conjugate in the mixture comprises a calcitonin drug coupled to an oligomer that includes a polyalkylene glycol moiety is disclosed. The mixture may lower serum calcium levels in a subject by 10, 15 or even 20 percent or more. Moreover, the mixture may be more effective at surviving an in vitro model of intestinal digestion than non-conjugated calcitonin. Furthermore, the mixture may exhibit a higher bioavailability than non-conjugated calcitonin.
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- Novel carbamate and oxamide compounds
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Disclosed are novel aromatic compounds of the formula(I) described herein, wherein G, E, W, Ar, X, Y and Z are disclosed herein. The compounds are useful for treating cytokine mediated diseases or conditions such as chronic inflammatory diseases. Also disclosed are pharmaceutical compositions containing and processes of making such compounds.
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- Reactions of trialkylalanes with cyclic acetals and orthoformates in CH2Cl2 and ClCH2CH2Cl as solvents
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Under mild conditions, trialkylalanes (Et3Al and Bu i3Al) in chlorine-containing solvents (CH 2Cl2 or ClCH2CH2Cl) react with cyclic acetals and orthoformates to form glycol monoethers and dialkylacetals, respectively, in high yields. The 1H NMR spectroscopic data demonstrate that CH2Cl2 or ClCH2CH 2Cl interacts with Bui3Al.
- Gafarova,Dekhtyar',Dekhtyar',Fatykhov,Spirikhin,Vostrikova,Zlotskii,Dokichev
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p. 1003 - 1008
(2007/10/03)
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- Pharmaceutically active compounds
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The present invention provides a compound of formula (I): where Q is a group of formula: These compounds inhibit cyclic guanosine 3′,5′-monophosphate phosphodiesterases (cGMP PDES). More notably, the compounds are potent and selective inhibitors of the type 5 cyclic guanosine 3′,5′-monophosphate phosphodiesterases and have utility therefore in a variety of therapeutic areas. In particular, the present compounds are of value for the curative or prophylactic treatment of mammalian sexual disorders.
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- Process for continuous production of dialkyl carbonate and diol
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A method for continuously producing a (A) dialkyl carbonate and a (B) diol, comprising continuously feeding a cyclic carbonate and an aliphatic monohydric alcohol to a continuous multi-stage distillation column to thereby effect a transesterification therebetween, thereby continuously producing a dialkyl carbonate and a diol, while continuously withdrawing a low boiling point mixture containing the produced dialkyl carbonate (A) in a gaseous form from an upper portion of the distillation column and continuously withdrawing a high boiling point mixture containing the produced diol (B) in a liquid form from a lower portion of the distillation column, wherein the transesterification is performed under conditions wherein: (a) the reaction pressure of the column bottom is 5×104Pa or less; (b) the reaction temperature of the column bottom is in the range of from ?20° C. to less than 60° C.; and (c) the distillation column has an F-factor in the range of from 0.2 to 5.0, the F-factor being represented by the following formula (1): F-factor=ug(ρg)???(1) wherein ugrepresents the gas velocity (m/s) in the distillation column and ρgrepresents the gas density (kg/m3) in the distillation column.
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Page column 25-32
(2008/06/13)
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- Process for the carbonylation of oxiranes
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A process is described for the carbonylation of an oxirane, such as ethylene oxide, which comprises reacting the oxirane under carbonylation conditions with carbon monoxide in a solvent, such as alkanol, for example methanol, in the presence of a cobalt catalyst and of an N-alkylated azole promoter, such as 1-methylpyrazole, and recovering the resulting carbonylation product, such as an alkyl ester of 3-hydroxypropionic acid, for example methyl 3-hydroxypropionate.
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- Process for preparing 1,3-alkanediol from epoxide derivative
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A process for preparing an 1,3-alkanediol through carbonylation of an epoxide derivative includes the steps of (a) reacting an epoxide derivative with alcohol and carbon monoxide in a solvent at a temperature from about 30 to about 150° C. and at a pressure from about 50 to about 3000 psig in the presence of a catalyst system including an effective amount of a cobalt catalyst and an effective amount of a promoter to afford a reaction mixture including a 3-hydroxyester or derivative thereof in an amount of from 2 to about 95% by weight, (b) separating the reaction product and solvent from the catalyst and promoter, (c) reacting said reaction product and solvent with hydrogen at a temperature from about 30 to about 350° C. and at a pressure from about 50 to about 5000 psig in the presence of a catalyst system for hydrogenation to prepare a hydrogenation product mixture including a 1,3-alkanediol, and (d) recovering the 1,3-alkanediol from the hydrogenation product mixture. Catalyst systems for carrying out the inventive processes are also provided.
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Page column 7-8
(2008/06/13)
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- Kinetic study of hydrolysis of benzoates. Part XXIII - Influence of the substituent and temperature on the kinetics of the alkaline hydrolysis of alkyl benzoates in aqueous 2.25 M Bu4NBr and 80% DMSO
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The second-order rate constants k2 (M-1 s-1) for the alkaline hydrolysis of substituted alkyl benzoates, C6H5CO(O)R (R = CH3, CH2Cl, CH2CN, CH2C≡CH, CH2C6H5, CH2CH2Cl, CH2CH2OCH3), were measured in aqueous 2.25 M n-Bu4NBr and in 80% (v/v) DMSO solution at several temperatures. The log k values were analyzed using the equation log k = log k0 + ρσ + δEsB. The EsB scale has been proposed for the steric effect of alkyl substituents in the alkyl part of esters: EsB = (log kR - log kCH(3))H+, where k is the rate constant for the acidic hydrolysis of substituted alkyl benzoates or acetates in water. As polar substituent parameters, both Taft σ* and σI constants were used. The dual parameter treatments of the log k values with σ and EsB constants gave excellent correlations (R = 0.997). For 2.25 M n-Bu4NBr, 80% (v/v) DMSO and pure water at 25 °C, calculated susceptibilities to the inductive effect of alkyl substituents ρ* were found to be 2.07, 2.21 and 1.64, respectively. The corresponding ρI values were 4.64, 4.94 and 3.64. The dependence of ρI on solvent and temperature in the alkaline hydrolysis of substituted alkyl benzoates was similar to that observed earlier for meta- and para-substituents in the alkaline hydrolysis of substituted phenyl benzoates and tosylates. The substituent dependence of the activation energy, E, was found to be completely caused by the polar effect. Susceptibility to steric effect in the alkaline hydrolysis of alkyl benzoates (δ ≈ 1) appeared to be independent of the solvent and temperature. Copyright
- Nummert, Vilve,Piirsalu, Mare
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p. 353 - 361
(2007/10/03)
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- Method of treating a patient having precancerous lesions with phenyl purinone derivatives
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Derivatives of Phenyl Purinone are useful for the treatment of patients having precancerous lesions. These compounds are also useful to inhibit growth of neoplastic cells.
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- Heterogeneous-Catalytic Dimerization of Methanol
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Oxide systems supported by α-Al2O3 and MgO were studied in oxidative dimerization of methanol. The highest selectivity is exhibited by tin oxide promoted with Na2O and La2O3 supported by magnesium oxi
- Kurina,Golovko,Galanov,Voronov,Sidorova,Novikov
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