- A gold(I) complex based on 1,8-naphthyridine functionalized N-heterocyclic carbene (NHC) and its catalytic activity
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A gold complex containing 2,7-bis(mesitylimidazolylidenyl)naphthyridine (NHC-NP) has been synthesized. Thus, reaction of [{Ag3(NHC-NP) 2}(PF6)3] with [Au(Me2S)Cl] provided an unusual digold complex bridged by two NHC-NP, forming a 20-membered dinuclear metallacycle [{Au2 (NHC-NP) 2Cl2}-(PF 6)2] (2) in high yield. This complex was characterized by spectroscopic and elemental analysis. This gold complex is active for the hydrolysis of 2,2,5-trimethyl-1,3-dioxane-5-methanol and can be recycled without losing the activity.
- Liu, Zu-Yin,Liu, Shiuh-Tzung
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Read Online
- Solution Dynamics of Hybrid Anderson-Evans Polyoxometalates
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Understanding the stability and speciation of metal-oxo clusters in solution is essential for many of their applications in different areas. In particular, hybrid organic-inorganic polyoxometalates (HPOMs) have been attracting increasing attention as they combine the complementary properties of organic ligands and metal-oxygen nanoclusters. Nevertheless, the speciation and solution behavior of HPOMs have been scarcely investigated. Hence, in this work, a series of HPOMs based on the archetypical Anderson-Evans structure, δ-[MnMo6O18{(OCH2)3C-R}2]3-, with different functional groups (R = -NH2, -CH3, -NHCOCH2Cl, -NCH(2-C5H4N) {pyridine; -Pyr}, and -NHCOC9H15N2OS {biotin; -Biot}) and countercations (tetrabutylammonium {TBA}, Li, Na, and K) were synthesized, and their solution behavior was studied in detail. In aqueous solutions, decomposition of HPOMs into the free organic ligand, [MoO4]2-, and free Mn3+ was observed over time and was shown to be highly dependent on the pH, temperature, and nature of the ligand functional group but largely independent of ionic strength or the nature of the countercation. Furthermore, hydrolysis of the amide and imine bonds often present in postfunctionalized HPOMs was also observed. Hence, HPOMs were shown to exhibit highly dynamic behavior in solution, which needs to be carefully considered when designing HPOMs, particularly for biological applications.
- Salazar Marcano, David E.,Lentink, Sarah,Moussawi, Mhamad A.,Parac-Vogt, Tatjana N.
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supporting information
p. 10215 - 10226
(2021/05/31)
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- Method for preparing trimethylolethane through continuous condensation hydrogenation method
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The invention relates to a method for preparing trimethylolethane through a continuous condensation hydrogenation method. According to the method, a condensation reaction still for achieving a continuous hydroxy aldehyde addition reaction of an impinging stream reactor, a gas-liquid-solid three-phase drip bed hydrogenation reactor and a bubbling type fluidized bed hydrogenation reactor are involved, and the two hydrogenation reactors are operated in series and contain a novel nickel hydrogenation catalyst and a main ingredient copper-chrome-aluminum-zinc catalyst respectively. It is guaranteed that formaldehyde and propionaldehyde stably generate a 2,2-dihydroxy methyl propyl aldehyde intermediate under organic weak alkali through the continuous impact steam aldol condensation reactor, generated byproducts are reduced, two hydrogenation reactions of different structures have the advantages of being high in conversion rate, simple in process, high in product purity, good in high temperature stability and the like, and the final yield of trimethylolethane can reach 95% or above.
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Paragraph 0008; 0075-0078
(2017/06/02)
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- Precise Steric Control over 2D versus 3D Self-Assembly of Antimony(III) Alkoxide Cages through Strong Secondary Bonding Interactions
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Antimony(III) alkoxide cages were designed as building blocks for predictable supramolecular self-assembly. Supramolecular synthons featuring two Sb···O secondary bonding interactions (SBIs), each SBI stronger than 30 kJ/mol, were used to drive the formation of the supramolecular architectures. Judicious choice of pendant groups provided predictable control over the formation of self-assembled 3D columnar helices, which crystallized with hollow morphologies, or a self-assembled 2D bilayer. The Sb-O stretching frequency provides a spectroscopic signature of Sb···O SBI formation.
- Moaven, Shiva,Yu, Jingze,Yasin, Jason,Unruh, Daniel K.,Cozzolino, Anthony F.
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supporting information
p. 8372 - 8380
(2017/07/22)
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- NOVEL HYDROGEN PEROXIDE-ACTIVABLE, ANTI-OXIDANT COMPOUNDS AND METHODS USING SAME
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The present invention includes 4-(hydroxymethyl)phenylboronic esters, which react with hydrogen peroxide to form 4-hydroxybenzyl alcohol, which is an anti-inflammatory and/or anti-oxidant compound. In certain embodiments, the compositions of the invention may be used to treat or prevent oxidative stress and/or inflammation, including ischemic disease.
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Page/Page column 21; 22; 27
(2016/06/01)
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- Alkylating potential of oxetanes
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Small, highly strained heterocycles are archetypical alkylating agents (oxiranes, β-lactones, aziridinium, and thiirinium ions). Oxetanes, which are tetragonal ethers, are higher homologues of oxiranes and reduced counterparts of β-lactones, and would therefore be expected to be active alkylating agents. Oxetanes are widely used in the manufacture of polymers, especially in organic light-emitting diodes (OLEDs), and are present, as a substructure, in compounds such as the widely used antimitotic taxol. Whereas the results of animal tests suggest that trimethylene oxide (TMO), the parent compound, and β,β-dimethyloxetane (DMOX) are active carcinogens at the site of injection, no studies have explored the alkylating ability and genotoxicity of oxetanes. This work addresses the issue using a mixed methodology: a kinetic study of the alkylation reaction of 4-(p-nitrobenzyl) pyridine (NBP), a trap for alkylating agents with nucleophilicity similar to that of DNA bases, by three oxetanes (TMO, DMOX, and methyloxetanemethanol), and a mutagenicity, genotoxicity, and cell viability study (Salmonella microsome test, BTC E. coli test, alkaline comet assay, and MTT assay). The results suggest either that oxetanes lack genotoxic capacity or that their mode of action is very different from that of epoxides and β-lactones.
- Gomez-Bombarelli, Rafael,Palma, Bernardo Brito,Martins, Celia,Kranendonk, Michel,Rodrigues, Antonio S.,Calle, Emilio,Rueff, Jose,Casado, Julio
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scheme or table
p. 1275 - 1281
(2011/02/28)
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- Chemoselective chemical and electrochemical deprotections of aromatic esters
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Alcohols can be easily and chemoselectively deprotected from the corresponding aromatic esters by using either SmI2/HMPA or by electrolysis In the presence of a proton source.
- Lam, Kevin,Marko, Istvan E.
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experimental part
p. 2752 - 2755
(2009/11/30)
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- Deprotection of acetals and ketals in a colloidal suspension generated by sodium tetrakis(3,5-trifluoromethylphenyl)borate in water
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Deprotection of acetals and ketals can be achieved by using sodium tetrakis(3,5-trifluoromethylphenyl)borate (NaBArF4) as the catalyst in water at 30°C. For example, a quantitative conversion of 2-phenyl-1,3-dioxolane into benzaldehyde was accomplished within five minutes by using this sodium salt (0.1 mol%) in water. Georg Thieme Verlag Stuttgart.
- Chang, Chih-Ching,Liao, Bei-Sih,Liu, Shiuh-Tzung
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p. 283 - 287
(2007/10/03)
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- Optically active phenoxypropionic esters
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Optically active compounds of the formula I STR1 where R is C1 -C12 -alkyl or -perfluoroalkyl in which one or two non-adjacent CH2 or CF2 groups can also be replaced by --O-- and/or --CO-- and/or --CO--O-- and/or --CH=CH-- and/or --CH-halogen-- and/or --CHCN-- and/or --0--CO--CH-halogen-- and/or --O--CO--CHCN--, or is C1 -C12 -alkyl which can have a terminal chemically reactive group and in which a CH2 group can be replaced by --O--, A1 and A2 are each, independently of one another, 1,4-phenylene which is unsubstituted or substituted by one or two F and/or Cl and/or Br atoms and/or CH3 groups and/or CN groups and in which one or two CH groups can also be replaced by N, 1,4-cyclohexylene in which one or two non-adjacent CH2 groups can also be replaced by --O-- and/or --S--, 1,4-piperidinediyl, 1,4-bicyclo[2.2.2]octylene, 2,6-naphthalenediyl, decahydro-2,6-naphthalenediyl or 1,2,3,4-tetrahydro-2,6-naphthalenediyl, A3 is unsubstituted or substituted phenyl, Z is --CO--O--, --O--CO--, --CH2 CH2 --, --OCH2 --, --CH2 O--, --C C-- or a single bond and m is 0, 1, 2 or 3.
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- Synthetic lubricating oil
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A synthetic lubricating oil contains an esterification product obtained from a hydroxycarboxylic acid polyol ester (A) and at least one aliphatic monocarboxylic acid (B), and optionally either an aliphatic carboxylic acid having two or more carboxyl groups (C) or a combination of an aliphatic carboxylic acid having two or more carboxyl groups (C) and an aliphatic polyhydric alcohol (D).
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- Catalysts for alkoxylation reactions
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Catalysts producing a sharply peaked alkoxylation distribution during the alkoxylation of organic materials comprise mixtures of BF3 and metal alkyls or metal alkoxides, SiF4 and metal alkyls or metal alkoxides, or mixtures of these catalysts.
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- Methods of alkoxylation
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Catalysts comprising mixtures of HF and metal alkoxides and mixed metal alkoxides produce a sharply peaked alkoxylation distribution during the alkoxylation of organic materials.
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- Catalysts for alkoxylation reactions
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Catalysts and a method of using said catalysts for the alkoxylation of a variety of materials is disclosed. Catalysts so described produce alkoxylates having a very sharp alkoxylate distribution. The catalysts are supported and unsupported dialkoxy and dialkyl metal fluorides and halides and alkyl metal difluorides and dihalides.
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- Kinetics and Mechanism for the Alkaline Homogeneous Hydrolysis of 1,1,1-Trimethylolethane Trinitrate
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The kinetics for the alkaline homogeneous hydrolysis of 1,1,1-trimethylolethane trinitrate (MTN) in 95percent ethanol-water with sodium hydroxide concentrations between 0.25 and 2.1 M and temperatures between 50.0 and 60.0 degC have been investigated.One mole of MTN was found to react with 3 mol of base and to hydrolize by a series of consecutive and competitive bimolecular and internal cyclization reactions involving three nitrate ester intermediates to form the cyclic alcohol ether 3-methyl-3-oxetanemethanol (AE) as the final major product with only trace amounts of the expected trialcohol 1,1,1-tris(hydroxymethyl)ethane (TA).MTN and its intermediates showed good second-order rate constants for the expression -d(MTN)/dt = k1(MTN) = k2(B-)(MTN), where k1 is the first-order rate constant with excess base, B-.Relative k2 values in 95percent ethanol-water, 95percent methanol-water, and water were found to be 1.0, 0.1, and 0.01, respectively.Hydrolysis kinetics and product formation for each nitrate ester intermediate have been determined, and an overall hydrolysis mechanism for MTN is presented.
- Hoffsommer, John C.,Glover, Donald J.,Burlinson, Nicholas E.
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p. 315 - 321
(2007/10/02)
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- Process for the preparation of trimethylolalkanes
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An improved process for the preparation of a trimethylolalkane of the formula STR1 wherein R1 denotes an aliphatic radical by reacting formaldehyde with an aldehyde of the formula STR2 wherein R1 has the meaning indicated above and thereafter hydrogenating the resultant 2,2-dimethylolalkanal, the improvement residing in employing formaldehyde in a molar ratio of at least 8:1 to the aldehyde reactant, carrying out the aldehyde-formaldehyde reaction in the presence of an aldol condensation base at a temperature between -20 and 5° C, optionally in the presence of an ion of an element of group VII and/or VIII and/or sub-group I or II of the periodic system.
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- Isoindolinone pigments and process for their manufacture
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Isoindolinone pigments of the formula STR1 WHEREIN R represents an aliphatic or cycloaliphatic radical, a cycloaliphatic, aromatic or heterocyclic radical to which the oxygen atoms are attached through alkyl or alkoxy groups, V1 and V2 represent hydrogen or halogen atoms, alkyl or alkoxy groups of 1 to 4 carbon atoms, X represents a halogen atom, Y and Z represent halogen atoms, alkoxy or alkylmercapto groups of 1 to 6 carbon atoms, cycloalkoxy groups of 5 to 6 carbon atoms, aralkoxy, aryloxy or arylmercapto groups, and n is an integer from 2 to 6, are valuable pigments coloring plastics, lacquers and printing inks in various yellow shades of excellent fastness properties and high color strength.
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