- Biomass alcoholysis method for petroleum-based plastic POM
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The invention discloses a biomass alcoholysis method for petroleum-based plastic POM. According to the method, simple biomass derivative alcohol and the petroleum-based plastic POM are allowed to generate a cyclic acetal product through dehydration condensation under catalytic conditions; low reaction cost and high added value are realized, and only water is byproduced and is easy to separate; and an obtained product has high added value, can be used for preparing organic solvents such as lignin and chromatographic analysis solvents, metal surface treatment agents or medical intermediates and monomers, realizes green, efficient and low-cost recovery, and has a high practical application value.
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Paragraph 0030-0051
(2021/05/01)
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- Efficient Plastic Waste Recycling to Value-Added Products by Integrated Biomass Processing
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The industrial production of polymeric materials is continuously increasing, but sustainable concepts directing towards a circular economy remain rather elusive. The present investigation focuses on the recycling of polyoxymethylene polymers, facilitated through combined catalytic processing of polymer waste and biomass-derived diols. The integrated concept enables the production of value-added cyclic acetals, which can flexibly function as solvents, fuel additives, pharmaceutical intermediates, and even monomeric materials for polymerization reactions. Based on this approach, an open-loop recycling of these waste materials can be envisaged in which the carbon content of the polymer waste is efficiently utilized as a C1 building block, paving the way to unprecedented possibilities within a circular economy of polyoxymethylene polymers.
- Beydoun, Kassem,Klankermayer, Jürgen
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p. 488 - 492
(2020/01/24)
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- Selective Conversion of Carbon Dioxide to Formaldehyde via a Bis(silyl)acetal: Incorporation of Isotopically Labeled C1 Moieties Derived from Carbon Dioxide into Organic Molecules
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The conversion of carbon dioxide to formaldehyde is a transformation that is of considerable significance in view of the fact that formaldehyde is a widely used chemical, but this conversion is challenging because CO2 is resistant to chemical transformations. Therefore, we report here that formaldehyde can be readily obtained from CO2 at room temperature via the bis(silyl)acetal, H2C(OSiPh3)2. Specifically, formaldehyde is released from H2C(OSiPh3)2 upon treatment with CsF at room temperature. H2C(OSiPh3)2 thus serves as a formaldehyde surrogate and provides a means to incorporate CHx (x = 1 or 2) moieties into organic molecules. Isotopologues of H2C(OSiPh3)2 may also be synthesized, thereby providing a convenient means to use CO2 as a source of isotopic labels in organic molecules.
- Rauch, Michael,Strater, Zack,Parkin, Gerard
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supporting information
p. 17754 - 17762
(2019/11/05)
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- Dimethyl sulfoxide as a "methylene" source: Ru(ii) photo-catalysed facile synthesis of acetals from alcohols
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Acetals are important molecules with versatile reactivity and uses. For the first time a simple photo-catalysed facile synthesis of formaldehyde acetals is documented herein upon the reaction of alcohols with dimethyl sulfoxide under very mild conditions in the presence of air. The reactions require only 1 mol% of RuII(bpy)3Cl2 photocatalyst under blue LED irradiation (λ = 445 nm) to give good to excellent yields of the corresponding acetal products. Here DMSO acts as a "methylene" source.
- Talukdar, Ranadeep
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supporting information
p. 13334 - 13338
(2019/09/06)
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- Ruthenium-Catalyzed Synthesis of Cyclic and Linear Acetals by the Combined Utilization of CO2, H2, and Biomass Derived Diols
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Herein a transition-metal catalyst system for the selective synthesis of cyclic and linear acetals from the combined utilization of carbon dioxide, molecular hydrogen, and biomass derived diols is presented. Detailed investigations on the substrate scope enabled the selectivity of the reaction to be largely guided and demonstrated the possibility of integrating a broad variety of substrate molecules. This approach allowed a change between the favored formation of cyclic acetals and linear acetals, originating from the bridging of two diols with a carbon-dioxide based methylene unit. This new synthesis option paves the way to novel fuels, solvents, or polymer building blocks, by the recently established “bio-hybrid” approach of integrating renewable energy, carbon dioxide, and biomass in a direct catalytic transformation.
- Beydoun, Kassem,Klankermayer, Jürgen
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supporting information
p. 11412 - 11415
(2019/07/18)
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- MANUFACTURE OF 1,3-PROPANEDIOL ESTERS
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Disclosed is a process for manufacturing an ester of 1,3-propanediol, comprising, contacting at a temperature of about 0 DEG C. to about 250 DEG C., ethylene, formaldehyde or a form of formaldehyde, a carboxylic acid, and a compound of the formula MZn.Qt, wherein: M is a zirconium[IV], cobalt[II], vanadium[IV], bismuth[II], tin[II], a rare earth metal, scandium or yttrium; n is the oxidation state of M; at least one of Z is an anion of the formula R1SO3- or R1CO2-, wherein R1 is hydrocarbyl or substituted hydrocarbyl containing 1 to 20 carbon atoms or part of a polymer, and the remainder of Z is oxo or one or more monovalent anions; Q is a neutral ligand; and t is 0 or an integer of 1 to 12.
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- C1-C6-epothilone fragments and process for the production of C1-C6-fragments of epothilones and derivatives thereof
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This invention describes C1-C6-epothilone fragments and an efficient process for the production of C1-C6-fragments of epothilones and derivatives thereof.
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- Transformation of 1,3-, 1,4- and 1,5-diols over perfluorinated resinsulfonic acid (Nafion-H)
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The transformations of 1,3-, 1,4- and 1,5-diols over perfluorinated resinsulfonic acids (Nafion-H) were studied and correlations were examined between the structure of the investigated diols, the possible transformation directions and the catalytic properties of Nafion-H. Comparisons were also made between the catalytic properties of Nafion-H and zeolites. The characteristic transformations of 1,3-diols depend on their structure. 1,3-Propanediol undergoes dehydration via 1,2-elimination and yields oligomers via intermolecular dehydration. 1,3-Diols with an alkyl substituent on the carbon between those bearing the OH groups undergo 1,2-elimination yielding unsaturated alcohols and dienes, and give carbonyl compounds via the loss of water and hydride shifts analogous to the pinacol rearrangement. The strong acidity of Nafion-H and the lack of strong basic sites are advantageous for the latter reaction. 1,3-Diols with two substituents at this position mainly yield fragmentation products. Stereoselective cyclodehydration to the corresponding oxacycloalkanes is the characteristic transformation of 1,4- and 1,5-diols over Nafion-H.
- Bucsi,Molnar,Bartok,Olah
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p. 3319 - 3326
(2007/10/02)
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- Montmorillonite, an efficient catalyst for the preparation of dialkoxymethanes
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The reaction of various alcohols with paraformaldehyde in presence of montmorillonite to give dialkoxymethanes (2a-g) in very good yield is described.
- Deshmukh,Gumaste,Bhawal
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p. 3939 - 3944
(2007/10/03)
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- Herbicidal glutarimides
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This invention relates to glutarimide compounds exhibiting herbicidal activity having the structure STR1 wherein A is carbonyl, thiocarbonyl or methylene, A1 is carbonyl or methylene, Q is O or (CH2)n where n is 0 or 1, D is CH or N and R, R1, R2, T, X, Y and Z are as defined within, compositions containing these compounds and methods of using these compounds as herbicides and algicides.
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- Process of using phospholipid derivatives to inhibit multiplication of the human immunodeficiency virus
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The present invention is concerned with the use of compounds of the general formula: STR1 and of the pharmacologically acceptable salts thereof, as well as of the optical isomers thereof for the preparation of pharmaceutical compositions with antiviral action. The present invention also provides new phospholipid derivatives.
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- Cationic complexes of technetium-99m
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The invention concerns cationic complexes of Technetium-99m with bidentate ligands (L), including complexes having the formulae [Tc(NO) X L2 ]+ and [Tc L3 ]+, which are of interest as heart imaging agents. The ligands are characterized by having the formula Y2 QZQY2, where each Q is phosphorus or arsenic, Z is a 2 or 3 carbon atom linking group, and at least one of the groups Y and Z includes at least one --COC--ether group.
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- New-quanidino-thiazol compounds, their preparation, and use as intermediates of famotidine process
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New 2-guanidino-thiazol compounds with the general formulas where R° represents an hydrogen atom or an alkyl group of low molecular weight, m = 2 to 7, n = 2 to 4, and being R an alkyl group of low molecular weight and that may contain from one N-alkylsilyl group, that are important intermediates for the famotidine preparation, medically used as inhibitor of the gastric secretion.
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- Percutaneous absorption enhancers, compositions containing same and method of use
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Novel 1,3-dioxolanes (1,3-dioxyacyclopentanes) are provided along with new 1,3-dioxolanes (1,3-dioxacyclopentanes) compositions which are useful in enhancing the absorption of therapeutic agents through the skin of humans and animals. The method for enhancing skin penetration of therapeutic agents using 1,3-dioxacycloalkanes is also described. The preferred compounds are 1,3-dioxolanes (1,3-dioxacyclopentanes) and 1,3-dioxanes (1,3-dioxacyclohexanes). The preferred compounds have the formula: STR1 wherein R, R0, R1, R2, R3, R4, R5 and R6 are each independently selected from hydrogen and C1 to C18 aliphatic groups, preferably alkyl, alkenyl, and the halo, hydroxy, carboxy, carboxamide and carboalkoxy substituted forms thereof, with at least one of said R's an alkyl or alkenyl group of C4 to C18 and n=0 or 1; the total number of carbon atoms in all of said R groups being no more than 40, and preferably less than 20 and not more than 1 thereof containing 18 or more carbon atoms.
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- Kinetic cyclohexylidenation and isopropylidenation of aldose diethyl dithioacetals
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Aldose diethyl dithioacetals react with 1.2 equivalents of 1-ethoxycyclohexene or 2-methoxypropene in N,N-dimethylformamide at 0° with p-toluenesulfonic acid as catalyst to give the five-membered ring acetal attached to the two terminal oxygen atoms as the major product in every case. In most instances, a small proportion of the terminal, six-membered ring acetal was also obtained, and in a few cases, terminal seven-membered ring acetals were also isolated. Cyclohexylidenation at room temperature gave the same products, but isopropyl-idenation at room temperature resulted in certain cases in partial rearrangement. Cyclohexylidenation reactions gave smaller proportions of the minor six- and seven-membered ring products. Structures were established from13C-n.m.r. and mass spectra. The13C-n.m.r. spectra of model cyclohexylidene derivatives were found very similar to those of isopropylidene derivatives previously studied. Two new features useful for structure determination were noted when the spectra of the precursor diols were compared with those of both types of derived acetals; the chemical shift of C-2 of a 1,3-propanediol derivative was shifted upfield by 6-9 p.p.m. on acetalation and the shifts of the diol carbon atoms attached to oxygen were affected according to the type of acetal and ring-size formed. Similar observations were made for methylene acetals.
- Grindley, T. Bruce,Cote, Christian J.P.,Wickramage, Chandra
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p. 215 - 238
(2007/10/02)
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- Acetolysis of Cyclic Acetals: Regioselective Acylative Cleavage of Cyclic Formals
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The acid-catalyzed reaction of cyclic acetals with acetic anhydride has been investigated.Acylative cleavage of cyclic formals has been found to be a clean, high-yield reaction involving rupture of the C(2)-O bond with loss of stereochemical integrity at the C(2)-position to give hemiacetal acetate products.Ring cleavage of unsymmetrically substituted cyclic formals with either acetic anhydride or acetyl chloride occurs via preferential rupture of the less congested C(2)-O bond (Scheme I, path A).Such cleavage is totally regiospecific for 1,3-dioxanes and displays high (75-85percent) regioselectivity for smaller and larger ring systems.Acetolysis of cyclic acetals other than formals is a slow process that leads to loss of the aldehyde derived fragment and formation of simple diacetates.These results are rationalized in terms of rate-limiting electrophilic attack that is acutely sensitive to steric effects engendered by substituents located at positions adjacent to ring oxygens.
- Bailey, William F.,Rivera, Alberto D.
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p. 4958 - 4964
(2007/10/02)
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- Process for the manufacture of ethers of hydroxy-pivalaldehyde
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Ethers of the hydroxypivalaldehyde RCH2 OCH2 C(CH3)2 CHO are prepared by a catalytic isomerization of 5,5-dimethyl-1,3-dioxans at 250° to 500° C. The catalyst is obtained by way of calcination from silicon dioxide, at least one element of the third main group or subgroup in the form of its oxide or hydroxide and at least one alkali metal oxide or hydroxide.
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- REACTION OF CYCLIC ACETALS WITH 1,3-DIOXANIUM SALTS
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The products from reaction of 1,3-dioxacycloalkanes with 1,3-dioxanium tetrafluoroborates are a new pair of compounds, i.e., 1,3-dioxacycloalkanium tetrafluoroborate and 1,3-dioxane.The reaction is reversible and takes place by a transacetalization mechanism.
- Chalova, O. B.,Kurmaeva, E. S.,Kantor, E. A.,Kiladze, T. K.,Rakhmankulov, D. L.
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p. 1434 - 1437
(2007/10/02)
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- Manufacture of gamma-butyrolactones from 1,3-glycols and esters, halides and metadioxanes thereof
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Gamma-butyrolactones are manufactured from olefins by reacting an olefin with an aldehyde to produce a 1,3-difunctional compound, reacting the 1,3-difunctional compound with carbon monoxide, and thereafter recovering the lactone thus produced.
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