- Iridium-Catalyzed Domino Hydroformylation/Hydrogenation of Olefins to Alcohols: Synergy of Two Ligands
-
A novel one-pot iridium-catalyzed domino hydroxymethylation of olefins, which relies on using two different ligands at the same time, is reported. DFT computation reveals different activities for the individual hydroformylation and hydrogenation steps in the presence of mono- and bidentate ligands. Whereas bidentate ligands have higher hydrogenation activity, monodentate ligands show higher hydroformylation activity. Accordingly, a catalyst system is introduced that uses dual ligands in the whole domino process. Control experiments show that the overall selectivity is kinetically controlled. Both computation and experiment explain the function of the two optimized ligands during the domino process.
- Beller, Matthias,Huang, Weiheng,Jackstell, Ralf,Jiao, Haijun,Tian, Xinxin
-
supporting information
(2022/01/13)
-
- Improving the Catalytic Stability of Ni/TiO2 for Ethanol Guerbet Condensation: Influence of Second Metal Component
-
Abstract: Ethanol Guerbet condensation (EGC) is a green process for preparing n-butanol and the development of highly effective solid catalysts is still the bottleneck of this reaction. In this work, a series of multifunctional catalysts Ni–X/TiO2 (X = Ru, Pt, Ir, Au, Cu, Mn, Co, Fe) were prepared by a co-impregnation method in order to improve the catalytic performance, especially the stability. It was found that the addition of the second metal component changed the acidity and alkalinity of Ni/TiO2 catalyst. What is more, acid site number affected ethanol conversion while alkali site number affected n-butanol selectivity. Among the Ni–X/TiO2 catalysts, Ni–Cu/TiO2 showed the best catalytic performance. The effects of preparation conditions on the catalytic performance of Ni–Cu/TiO2 were investigated and the results showed that the suitable preparation conditions were as follows: a Ni/Cu mass ratio of 59 : 1, a Ni–Cu loading of 12.5 wt %, a calcination temperature of 450°C, a calcination time of 2 h, a reduction temperature of 400°C, and a reduction time of 4?h. At a 10 wt % of catalyst loading, a reaction temperature of 210°C and a reaction time of 10 h, the ethanol conversion and the selectivity of n-butanol were 47.9 and 44.4%, respectively. Moreover, the stability of Ni–Cu/TiO2 catalyst was greatly improved due to the interaction between Ni and Cu as compared with the Ni/TiO2 catalyst: the catalytic activity of Ni–Cu/TiO2 did not decline significantly for reuse in three cycles.
- An, Hualiang,Han, Xiaoxu,Li, Shuaiqi,Wang, Yanji,Zhao, Xinqiang
-
p. 632 - 640
(2021/09/28)
-
- Upgrading of Ethanol to n-Butanol via a Ruthenium Catalyst in Aqueous Solution
-
The upgrading of ethanol to n-butanol via the Guerbet reaction in aqueous media has been developed. This system allows for the upgrading of ethanol to n-butanol in up to a 28% yield and 57% selectivity, at only 80 °C. This system is also able to tolerate the same feedstock ratio found in fermentation broth (water to ethanol ratio of 90:10), albeit a decrease in yield and selectivity (20% yield of n-butanol, 48% selectivity). Smaller amounts of longer-chain alcohols are also formed.
- Dibenedetto, Tarah A.,Jones, William D.
-
supporting information
p. 1884 - 1888
(2021/06/30)
-
- PROCESSES FOR PRODUCING ALCOHOLS FROM BIOMASS AND FURTHER PRODUCTS DERIVED THEREFROM
-
Processes for producing alcohols from biomass are provided. The processes utilize supercritical methanol to depolymerize biomass with subsequent conversion to a mixture of alcohols. In particular the disclosure relates to continuous processes which produce high yields of alcohols through recycling gases and further employ dual reactor configurations which improve overall alcohol yields. Processes for producing higher ethers and olefins from the so-formed alcohols, through alcohol coupling and subsequent dehydration are also provided. The resulting distillate range ethers and olefins are useful as components in liquid fuels, such as diesel and jet fuel.
- -
-
Paragraph 0539-0540
(2021/11/26)
-
- Preparation method of remdesivir intermediate 2-ethyl-1-butanol
-
The invention relates to a preparation method of a remdesivir intermediate 2-ethyl-1-butanol. The preparation method comprises a step of substitution reaction, namely a step of carrying out a substitution reaction on alkyl acetoacetate and halogenated ethane under an alkaline condition to obtain alkyl 2-ethyl-3-oxo-butyrate; a step of addition reduction, namely a step of carrying out an addition reduction reaction on the alkyl 2-ethyl-3-oxo-butyate to obtain alkyl 2-ethylbutyrate; a step of reduction, namely a step of subjecting the alkyl 2-ethylbutyrate to a reduction reaction to prepare 2-ethyl-1-butanol (I). According to the preparation method of the remdesivir intermediate 2-ethyl-1-butanol, the alkyl acetoacetate and halogenated ethane serve as main raw materials, the raw materials are simple and easy to obtain, the 2-ethyl-1-butanol (I) is prepared through substitution reaction, addition reduction and reduction reaction, the process is simple, economical and environmentally friendly, the product is convenient to obtain, and industrial production of remdesivir bulk drugs is facilitated.
- -
-
Paragraph 0049-0050
(2020/08/09)
-
- SATURATED HOMOETHER MANUFACTURING METHOD FROM UNSATURATED CARBONYL COMPOUND
-
PROBLEM TO BE SOLVED: To provide a method for manufacturing saturated homoether from an unsaturated carboxyl compound at good efficiency. SOLUTION: There is provided a manufacturing method of saturated homoether using an unsaturated carboxyl compound and hydrogen as raw materials, and a catalyst in which a metal is carried on an acidic catalyst carrier. The metal of the catalyst is for example palladium, and the carrier of the catalyst is alumina, silica, silica-alumina, or the like. The unsaturated carbonyl compound as the raw material is 2-butenal, 2-ethyl-2-hexenal, 2-ethyl-2-butenal, 2-hexenal, and manufactured saturated homoether is dibuthylether, bis(2-ethylhexyl)ether, bis(2-ethylbuty)ether, dihexylether, or the like. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPO&INPIT
- -
-
Paragraph 0037-0038; 0040; 0044; 0047-0048
(2020/05/14)
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- Successive vapour phase Guerbet condensation of ethanol and 1-butanol over Mg-Al oxide catalysts in a flow reactor
-
The successive vapour phase condensation of ethanol and 1-butanol (via Guerbet reaction) in a flow reactor under atmospheric pressure was studied over catalytic Mg-Al oxide compositions. Wherein the vapour phase condensation of 1-butanol to 2-ethyl-1-hexanol in flow has been investigated for the first time. The acid/base capacity ratio, which is determined by the Mg/Al ratio, is an important characteristic for the activity and selectivity of Mg-Al oxide catalysts in the abovementioned processes. The carbon chain length of the reacting alcohols, an arrangement of surface active sites and other steric factors also have an impact on Guerbet condensation in the vapour phase. High productivity of Mg-Al oxide system to the Guerbet alcohols: 1-butanol – 25 g/(Lcat·h), 2-ethyl-1-hexanol – 19 g/(Lcat·h), has been achieved. The results have shown a prospect of successive conversion realization: 1) ethanol → 1-butanol; 2) 1-butanol → 2-ethyl-1-hexanol for the production of 2-ethyl-1-hexanol from ethanol.
- Larina, Olga V.,Valihura, Karina V.,Kyriienko, Pavlo I.,Vlasenko, Nina V.,Balakin, Dmytro Yu.,Khalakhan, Ivan,?endak, Toma?,Soloviev, Sergiy O.,Orlyk, Svitlana M.
-
-
- METHODS AND COMPOSITIONS FOR THE CATALYTIC UPGRADING OF ALCOHOLS
-
Compositions and methods of use related to metal organic frameworks (MOFs) and/or nanoparticles are generally described. In some embodiments, methods and compositions for the catalytic upgrading of alcohols using MOFs and/or nanoparticles associated with MOFs are generally described. In some embodiments, a catalytic MOF composition is provided, wherein the MOF composition comprises a MOF compound and a plurality of metal catalytic compounds. In some embodiments, an alcohol may be exposed to the MOF composition and/or a plurality of nanoparticles associated with the MOF composition such that the alcohol is converted to a higher order alcohol. Advantageously, in some embodiments, the alcohol conversion occurs at a relatively high turnover frequency and/or with a relatively high selectivity as compared to traditional methods for converting alcohols.
- -
-
Paragraph 0184; 0188; 0189
(2019/12/02)
-
- Catalytic synthesis of distillate-range ethers and olefins from ethanol through Guerbet coupling and etherification
-
Synthesis of distillate-range fuels from biomass-derived alcohols has recently received considerable attention due to projected increases in the demands of these fuels and the extensive commercialization of alcohol production. Here we present a two-stage process by which an alcohol such as ethanol or 1-butanol can be converted with high yields into distillate-range ethers and olefins by combining Guerbet coupling and intermolecular dehydration. The ethers can be used as cetane-improvers in diesel fuel, while the olefins can be hydrogenated and blended with gasoline or oligomerized and hydrogenated to jet-range paraffins. The first stage was executed using calcium hydroxyapatite to produce higher linear and branched alcohols at above 80% selectivity at up to 40% conversion with high stability for over 400 h time-on-stream operation. Increasing conversion decreases selectivity, producing predominantly mono-ene and diene byproducts. Etherification was performed using the acidic resin Amberlyst 70 at around 65% conversion. Linear alcohols were converted at above 90% selectivity while branched alcohols were far more selective to olefins (65-75%). Etherification occurs via two mechanisms: a direct mechanism involving the reaction of two alcohols and an indirect mechanism between an alcohol and equilibrated pool of olefins. Cross-etherification was observed between linear and branched alcohols, improving the selectivity to ethers in conversion of the latter. A mixture of C4+ alcohols produced from ethanol condensation at 40% conversion was effectively utilized in etherification at selectivities comparable to the model mixtures. An overall process is presented for the conversion of ethanol to diesel-range ethers and olefins with yields of approximately 80%.
- Eagan, Nathaniel M.,Moore, Benjamin M.,McCelland, Daniel J.,Wittrig, Ashley M.,Canales, Emmanuel,Lanci, Michael P.,Huber, George W.
-
p. 3300 - 3318
(2019/06/24)
-
- Importance of the Nature of the Active Acid/Base Pairs of Hydroxyapatite Involved in the Catalytic Transformation of Ethanol to n-Butanol Revealed by Operando DRIFTS
-
Operando DRIFTS is used to identify the nature and the role of the surface sites of hydroxyapatites (HAps) involved in the catalytic transformation of ethanol to n-butanol. The surface processes occurring upon a first reaction step followed by a step under He flow greatly influence the reactivity of HAps in a subsequent second reaction step. Ethanol is found to be mostly activated by the basic OH? groups of HAps, as indicated by the concomitant recovery of ethanol conversion and OH? groups under He flow. The drastic changes in selectivity observed during the second reaction step reveal the key role of acidic sites cooperatively acting with basic sites for basic reaction steps. Once the POH groups are poisoned by extensive formation of polymeric carbon species and the Ca2+ sites are available, the production of acetaldehyde is drastically promoted at the expense of that of n-butanol. It is concluded that i) acetaldehyde acts as an intermediate in the formation of n-butanol, and ii) various active sites are involved in the key basic reaction steps such as Ca2+?OH? and POH?OH? acid-base pairs in the dehydrogenation of ethanol to acetaldehyde and the aldol condensation for n-butanol formation, respectively.
- Osman, Manel Ben,Krafft, Jean-Marc,Thomas, Cyril,Yoshioka, Tetsuya,Kubo, Jun,Costentin, Guylène
-
p. 1765 - 1778
(2019/02/26)
-
- Tris(pyrazolyl)borate Cobalt-Catalyzed Hydrogenation of C=O, C=C, and C=N Bonds: An Assistant Role of a Lewis Base
-
The combination of tris(pyrazolyl)borate cobalt complexes and Lewis base is developed as an efficient catalyst precursor in the homogeneous hydrogenation. A broad substrate scope including carbonyls, alkenes, enamines, and imines is reduced with 60 atm of H2 at 60 °C. Mechanistic studies support the hydrogenation operates through a frustrated Lewis pair (FLP)-like reduction process. These results highlight the development of novel non-noble metal catalytic processes, when combined with the diverse small molecule activation chemistry associated with FLPs.
- Lin, Yang,Zhu, De-Ping,Du, Yi-Ran,Zhang, Rui,Zhang, Suo-Jiang,Xu, Bao-Hua
-
supporting information
p. 2693 - 2698
(2019/04/25)
-
- Catalytic Upgrading of Ethanol to n-Butanol via Manganese-Mediated Guerbet Reaction
-
Replacement of precious metal catalysts in the Guerbet upgrade of ethanol to n-butanol with first-row metal complex catalysts is highly appreciated due to their economic and environmental friendliness. The manganese pincer complexes of the type [(RPNP)MnBr(CO)2] (R = iPr, Cy, tBu, Ph or Ad) are found to be excellent catalysts for upgrading ethanol to n-butanol. Under suitable reaction conditions and with an appropriate base, about 34% yield of n-butanol can be obtained in high selectivity. A detailed account on the effect of the temperature, solvent, nature, and proportion of base used and the stereoelectronic effects of the ligand substituents on the catalytic activity of the catalysts as well as the plausible deactivation pathways is presented.
- Kulkarni, Naveen V.,Brennessel, William W.,Jones, William D.
-
p. 997 - 1002
(2018/02/14)
-
- Guerbet Reaction over Strontium-Substituted Hydroxyapatite Catalysts Prepared at Various (Ca+Sr)/P Ratios
-
The Guerbet reaction of ethanol to heavier products was performed over a series of extensively characterized Sr-substituted hydroxyapatites (HAPs) with different (Ca+Sr)/P ratios, and thus different structural, textural, and acid–base properties. The acid–base properties were correlated with the reactivity of the solids and an optimal ratio between the amount of acid and basic sites was determined (ca. 4), whereas the ethanol conversion was mainly depending on the specific surface area of the solids. The stoichiometric 100 mol % Sr-substituted sample (SrAp-100) was especially efficient in higher alcohols production, which can be illustrated by a total alcohol selectivity (76.4 %) higher than that of all the other solids at a 13 % ethanol isoconversion.
- Silvester, Lishil,Lamonier, Jean-Fran?ois,Lamonier, Carole,Capron, Micka?l,Vannier, Rose-No?lle,Mamede, Anne-Sophie,Dumeignil, Franck
-
p. 2250 - 2261
(2017/06/27)
-
- Acetaldehyde as an ethanol derived bio-building block: An alternative to Guerbet chemistry
-
In this work, we describe a highly selective poly-aldol condensation of acetaldehyde, which can readily be obtained via dehydrogenation of ethanol. The process operates under mild temperatures (100°C or less) using commercially available catalysts and exhibits excellent total carbon yield of C4+ products with good selectivity for C6 products. The products derived from the reactions described herein are shown to be candidate drop-in fuel replacements for compression ignition engines and precursors to valuable chemicals.
- Moore, Cameron M.,Staples, Orion,Jenkins, Rhodri W.,Brooks, Ty J.,Semelsberger, Troy A.,Sutton, Andrew D.
-
supporting information
p. 169 - 174
(2017/01/24)
-
- Conversion of ethanol into linear primary alcohols on gold, nickel, and gold–nickel catalysts
-
The direct conversion of ethanol into the linear primary alcohols CnH2n+1OH (n = 4, 6, and 8) in the presence of the original mono- and bimetallic catalysts Au/Al2O3, Ni/Al2O3, and Au–Ni/Al2O3 was studied. It was established that the rate and selectivity of the reaction performed under the conditions of a supercritical state of ethanol sharply increased in the presence of Au–Ni/Al2O3. The yield of target products on the bimetallic catalyst was higher by a factor of 2–3 than that reached on the monometallic analogs. Differences in the catalytic behaviors of the Au, Ni, and Au–Ni systems were discussed with consideration for their structure peculiarities and reaction mechanisms.
- Chistyakov,Zharova,Tsodikov,Nikolaev,Krotova,Ezzhelenko
-
p. 803 - 811
(2016/12/07)
-
- Highly Efficient Process for Production of Biofuel from Ethanol Catalyzed by Ruthenium Pincer Complexes
-
A highly efficient ruthenium pincer-catalyzed Guerbet-type process for the production of biofuel from ethanol has been developed. It produces the highest conversion of ethanol (73.4%, 0.02 mol% catalyst) for a Guerbet-type reaction, including significant amounts of C4 (35.8% yield), C6 (28.2% yield), and C8 (9.4% yield) alcohols. Catalyst loadings as low as 0.001 mol% can be used, leading to a record turnover number of 18 ?209. Mechanistic studies reveal the likely active ruthenium species and the main deactivation process.
- Xie, Yinjun,Ben-David, Yehoshoa,Shimon, Linda J. W.,Milstein, David
-
supporting information
p. 9077 - 9080
(2016/08/05)
-
- PROCESS FOR PRODUCTION OF BRANCHED CHAIN ALCOHOLS
-
The invention relates generally to the uses of biocatalytic processes to obtain branched chain alcohols. The invention also relates to fuel compositions comprising said alcohols.
- -
-
Page/Page column 34; 35
(2016/02/29)
-
- Method of producing hydrogen of the reaction product and substrate
-
PROBLEM TO BE SOLVED: To provide a new production method requiring no reactor having high stirring power for high-temperature and high-pressure conditions in a gas-liquid catalytic reaction of a liquid phase of a substrate with hydrogen in the presence of a solid catalyst. SOLUTION: Micro or nano bubbles are introduced into a liquid phase consisting of a solvent and a substrate so that a reaction product is produced by gas-liquid contact of the substrate with hydrogen in the presence of the solid catalyst. The substrate is one of organic compounds having an unsaturated carbon bond and secondary and tertiary alcohols. COPYRIGHT: (C)2013,JPOandINPIT
- -
-
Paragraph 0060; 0061
(2017/03/24)
-
- Reactivity of ethanol over hydroxyapatite-based Ca-enriched catalysts with various carbonate contents
-
The Guerbet reaction of ethanol to produce heavier products was performed over a series of extensively characterized carbonate-containing hydroxyapatites (HAPs) with different Ca/P ratios and thus different densities, strengths and natures of acid and bas
- Silvester, Lishil,Lamonier, Jean-Fran?ois,Faye, Jérémy,Capron, Micka?l,Vannier, Rose-No?lle,Lamonier, Carole,Dubois, Jean-Luc,Couturier, Jean-Luc,Calais, Christophe,Dumeignil, Franck
-
p. 2994 - 3006
(2015/05/13)
-
- Process for the preparation of n-butanol from ethanol and acetaldehyde
-
The present invention generally relates to processes for preparation of higher alcohols such as n-butanol from lower alcohols such as ethanol by Guerbet condensation. In some aspects, the present invention relates to improvements in n-butanol yield and selectivity by the selection of process reaction conditions such as, but not limited to, mole ratio of hydrogen to ethanol, mole ratio of acetaldehyde to ethanol, mole ratio of ethyl acetate to ethanol and/or mole ratio of carbon monoxide to ethanol.
- -
-
Paragraph 0094; 0095; 0099; 0100; 0101
(2015/07/15)
-
- Production of Higher Alcohols
-
A reactive distillation method comprises introducing a feed stream to a reactive distillation column, contacting the feed stream with one or more catalysts in the reactive distillation column during a distillation, and removing one or more higher alcohols during the distillation from the reactive distillation column as a bottoms stream. The feed stream comprises one or more alpha hydrogen alcohols, and the feed stream reacts in the presence of the one or more catalysts to produce a reaction product comprising the one or more higher alcohols.
- -
-
Paragraph 0198-0200
(2014/09/03)
-
- Direct self-condensation of bio-alcohols in the aqueous phase
-
Bio-alcohols (e.g. ethanol, butanol) are primarily obtained as diluted aqueous solutions from biomass fermentation, and thus the subsequent isolation is a very costly process. So the direct transformation of bio-alcohols in water will have great advantages. This study describes the development of catalysts used for the self-condensation of bio-alcohols in water (that mimic the primary fermentation solutions). Efficient iridium catalysts have been developed rationally from homogeneous to heterogeneous, and the immobilized catalysts could be reused without any loss of activity, which is very important for the development of practical processes. The expected self-condensation could be realized with 80-90% selectivity in water and air. Such a protocol might be used for producing butanol from ethanol solution directly, which is an improved higher-alcohol biofuel. Other useful chemicals, such as 2-ethylhexanol, could also be obtained from renewable resources through this condensation reaction. This journal is the Partner Organisations 2014.
- Xu, Guoqiang,Lammens, Tijs,Liu, Qiang,Wang, Xicheng,Dong, Linlin,Caiazzo, Aldo,Ashraf, Nadim,Guan, Jing,Mu, Xindong
-
p. 3971 - 3977
(2014/08/05)
-
- Indium tri(isopropoxide)-catalyzed selective Meerwein-Ponndorf-Verley reduction of aliphatic and aromatic aldehydes
-
Indium tri(isopropoxide)-catalyzed Meerwein-Ponndorf-Verley reduction of aliphatic and aromatic aldehydes in 2-propanol gave selectively the corresponding primary alcohols in good to excellent yields at room temperature. A wide range of functional groups including alkene, ether, ketone, ester, nitrile, and nitro were tolerated under the optimum reaction conditions. Chemoselective reductions were also achieved not only between aromatic aldehyde, aromatic ketone, and epoxide but also between aliphatic aldehyde and alkene.
- Lee, Jaeyoung,Ryu, Taekyu,Park, Sangjune,Lee, Phil Ho
-
supporting information; experimental part
p. 4821 - 4825
(2012/07/03)
-
- Reaction of ethanol over hydroxyapatite affected by Ca/P ratio of catalyst
-
The mineral hydroxyapatite [HAP; Ca10(PO4)6(OH)2] is the chief component of animal bones and teeth. It also is known to function as a catalyst with both acid and base sites, depending on the manner in which it is synthesized. We closely studied the reaction of ethanol over HAP using catalysts of different Ca/P molar ratios. These were prepared by controlling the pH of the solution during precipitation synthesis. We found that the distribution of acid sites and basic sites on the catalyst surface varied with the Ca/P ratio of HAP. The yields of ethylene, 1-butanol, and 1,3-butadiene were correlated with the ratio of acid sites and basic sites. We further found that yields of higher alcohols, such as 1-butanol, that are known as Guerbet alcohols and are characteristic products of ethanol over HAP, are functions of the probability of ethanol activation (α) on the catalyst surface.
- Tsuchida, Takashi,Kubo, Jun,Yoshioka, Tetsuya,Sakuma, Shuji,Takeguchi, Tatsuya,Ueda, Wataru
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experimental part
p. 183 - 189
(2009/03/11)
-
- PROCESS FOR PRODUCING AROMATIC CARBONATE
-
A process for producing an aromatic carbonate, characterized by continuously feeding an aliphatic carbonate represented by the following general formula (1) as a starting material, an aromatic monohydroxy compound represented by the following general formula (2) as a reactant, and a metal-containing catalyst to a first multistage distillation column at a stage upper than the bottom of the column to react the starting material with the reactant and continuously discharging an aromatic carbonate compound represented by the following general formula (3) in a liquid state, which is obtained from the starting material and the reactant, from the column bottom while low-boiling ingredients generated as by-products of the reaction, such as an alcohol, are being continuously discharged in a gaseous state from the reaction system. In the general formula (1) and (2), R1 represents a C4-6 aliphatic group and Ar1 represents a C5-30 aromatic group. In the general formula (3), R2 and Ar2 respectively are R1 and Ar1 in the starting material and the reactant.
- -
-
Page/Page column 31-32
(2008/06/13)
-
- Reaction network of aldehyde hydrogenation over sulfided Ni-Mo/Al 2O3 catalysts
-
A reaction network of aldehyde hydrogenation over NiMoS/Al 2O3 catalysts was studied with aldehydes with straight and branched carbon chains and different chain lengths as feed materials. The reactions in the gas phase and the liquid phase were compared. The main reaction in the aldehyde hydrogenation process is the hydrogenation of the CO double bond, which takes place over the coordinatively unsaturated sites. The major side reactions are self-condensation of aldehydes and condensation of aldehydes with alcohols. Both reactions involve α-hydrogen and are primarily catalyzed by acid-base bifunctional sites over the exposed Al2O 3 surfaces.
- Wang, Xueqin,Saleh, Ramzi Y.,Ozkan, Umit S.
-
-
- An amino alcohol ligand for highly enantioselective addition of organozinc reagents to aldehydes: Serendipity rules
-
(matrix presented) Amino alcohol 4 (or its enantiomer) is prepared in two simple steps. Commercial (1R,2S)-2-amino-1,2-diphenylethanol is dialkylated with bis(2-bromoethyl) ether. Subsequent hydrogenation over 5% Rh on alumina in the presence of morpholine unexpectedly stops at the hexahydro derivative 4. Amino alcohol 4 promotes the enantioselective addition of diethylzinc to aldehydes at room temperature in up to 99% enantiomeric excess.
- Nugent, William A.
-
p. 2133 - 2136
(2007/10/03)
-
- Process for the persistence control of chemicals released into the environment
-
The invention provides contaminant-reducing agent delivery compositions that are useful for the control of organic or inorganic contaminants in aquatic or terrestrial environments. The compositions comprise one or more superabsorbent solid organic polymers and at least one contaminant-reducing agent. These superabsorbent polymers act as the primary carriers of one or more contaminant-reducing agents effective for the control of organic or inorganic contaminants in aquatic or terrestrial environments. Contaminant-reducing agents include film-forming agents, microbial agents, nutrient agents, and mixtures thereof. The invention also provides a method to entrap and accumulate organic and inorganic contaminants in one or more superabsorbent polymer compositions containing no contaminant-reducing agent. The invention also provides a method to entrap water in superabsorbent polymers to activate natural and applied microbial and nutrient contaminant-reducing agents in terrestrial environments.
- -
-
-
- Compositions and methods for reducing the amount of contaminants in aquatic and terrestrial environments
-
The invention provides contaminant-reducing agent delivery compositions that are useful for the control of organic or inorganic contaminants in aquatic or terrestrial environments. The compositions comprise one or more superabsorbent solid organic polymers and at least one contaminant-reducing agent. These superabsorbent polymers act as the primary carriers of one or more contaminant-reducing agents effective for the control of organic or inorganic contaminants in aquatic or terrestrial environments. Contaminant-reducing agents include film-forming agents, microbial agents, nutrient agents, and mixtures thereof. The invention also provides a method to entrap and accumulate organic and inorganic contaminants in one or more superabsorbent polymer compositions containing no contaminant-reducing agent. The invention also provides a method to entrap water in superabsorbent polymers to activate natural and applied microbial and nutrient contaminant-reducing agents in terrestrial environments.
- -
-
-
- Regioselective Reductive Cleavage of Terminal Epoxides with Polymer-supported Chloroaluminium Tetrahydroborate
-
Epoxides are reduced exclusively to the less substituted alcohols with regenerable polyvinylpyridine-supported chloroaluminium tetrahydroborate in high yields.
- Tamami, Bahman,Lakouraj, M. Mansour,Yeganeh, Hamid
-
p. 330 - 331
(2007/10/03)
-
- Highly chemoselective reduction of aldehyde function catalyzed by polymer-bound Rh6 cluster complex under water-gas shift reaction conditions
-
A functionalized polymer-bound Rh6 cluster complex showed high catalytic activity for chemoselective reduction of aldehydes in the presence of CO and H2O. The reaction system consists of the triphase, which makes work-up procedure simple.
- Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
-
p. 3005 - 3008
(2007/10/03)
-
- Modofied Borohydride Agents, (1,4-Diazabicyclooctane)(tetrahydroboronato)zinc Complex . A New Ligand Metal Borohydride as a Stable, Efficient, and Versatile Reducing Agent
-
(1,4-Diazabicyclooctane)(tetrahydroborato)zinc complex is a stable compound which has been used for the selective reduction of aldehydes, ketones, α,β-unsaturated carbonyl compounds, α-diketones, acyloins and acyl chlorides to their alcohols and aldehydes in THF or CH2Cl2/hexane at room temperature or under reflux conditions.
- Firouzabadi, Habib,Zeynizadeh, Behzad
-
p. 156 - 168
(2007/10/03)
-
- Poly-η-(pyrazine)zinc borohydride as a new stable, efficient and selective reducing agent
-
Coordination polymer of unstable zinc borohydride and pyrazine is prepared and used as an stable, efficient and selective bench top reducing agent for a variety of organic compounds.
- Tamami,Lakouraj
-
p. 3089 - 3096
(2007/10/03)
-
- Novel conversion of aldehydes to boronic esters. Simultaneous IGOR2 computer generation and experimental observation of an unusual rearrangement of 0α-aminoboranes
-
Utilization of the IGOR2 (Interactive Generation of Organic Reactions 2) program to study the addition of the boron-hydrogen bond to various carbon-carbon and carbon-heteroatom double bonds is reported. The IGOR2 program not only generated a number of hydroboration reactions but also indicated an unusual rearrangement of α-aminomonoalkylboranes to the corresponding B-(dialkylamino)monoalkylboranes. Independent and simultaneous experimental observation of these IGOR2-generated rearrangements was made during the hydroboration of β,β-disubstituted morpholino and piperidino enamines. Thus, the hydroboration of 2-ethyl-l-morpholino-1-butene using borane-methyl sulfide (BMS) gave B-morpholinoborane as a byproduct. Additionally, upon oxidation, 2-ethyl-1-butanol was isolated from the reaction mixture. These results are explained in terms of unusual rearrangements of the α-(dialkylamino)monoalkylborane intermediate. The use of BH3-THF-BF3-OEt2 or NaBH4-BF3OEt2 for the hydroboration permits the utilization of any β, γ-disubstituted enamine in this rearrangement reaction and vastly improves the yields of the rearrangement products. Nonoxidative workup of the rearrangement reaction mixture affords excellent yields of the corresponding boronic acids, which were isolated as 2-alkyl-1,3,2-dioxaborinanes.
- Fisher, Gary B.,Juarez-Brambila, Jesus J.,Gorakki, Christian T.,Wipke, W. Todd,Singaram, Bakthan
-
p. 440 - 444
(2007/10/02)
-
- Mixed Sovents Containing Methanol as Useful Reaction Media for Unique Chemoselective Reductions with Lithium Borohydride
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The reducing ability of lithium borohydride is greatly enhanced in mixed solvents containing methanol.Esters, lactones, and epoxides are reduced chemoselectively more rapidly with LiBH4-MeOH (1 equiv added at the beginning)-ether than with LiBH4-ether in the presence of the other reducible groups such as carboxylic acid, chloro, nitro, and carbamoyl.On the other hand, nitro, nitrile, carboxyl, and primary and tertiary amide groups are reduced with LiBH4-MeOH(4 equiv dropwise addition)-diglyme(or tetrahydrofuran).However, secondary amides derived from aliphatic amines and metal carboxylate are not reduced.Thus, unique chemoselective reductions of primary amide in the presence of secondary amide or metal carboxylate are achieved.
- Soai, Kenso,Ookawa, Atsuhiro
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p. 4000 - 4005
(2007/10/02)
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- PRACTICAL PROCEDURE FOR THE CHEMOSELECTIVE REDUCTION OF ESTERS BY SODIUM BOROHYDRIDE. EFFECT OF THE SLOW ADDITION OF METHANOL.
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The effect of solvents on the reduction of esters was examined with readily available sodium borohydride which is known to be incapable of reducing such functional groups. In mixed solvents of t-butyl alcohol-methanol or tetrahydrofuran-methanol, various carboxylic esters and lactones were found to be reduced by sodium borohydride to the corresponding alcohols or diols in high yields. Slow addition of methanol to the refluxing mixture of ester and sodium borohydride in t-butyl alcohol or tetrahydrofuran was essential to achieve effective reduction. On the other hand, each individual solvent, methanol or t-butyl alcohol, was not effective for the reduction.
- Soai,Oyamada,Takase,Ookawa
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p. 1948 - 1953
(2007/10/02)
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