- Photolabile dendrimers using o-nitrobenzyl ether linkages
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(Formula presented) Benzyl aryl ether dendrimers containing photosensitive, veratryl-based o-nitrobenzyl AB linkages (bold bonds) were prepared to the third generation and shown to undergo site-specific degradation when irradiated with ultraviolet light.
- Smet, Mario,Liao, Li-Xin,Dehaen, Wim,McGrath, Dominic V.
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Read Online
- Clip-off Chemistry: Synthesis by Programmed Disassembly of Reticular Materials**
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Bond breaking is an essential process in chemical transformations and the ability of researchers to strategically dictate which bonds in a given system will be broken translates to greater synthetic control. Here, we report extending the concept of selective bond breaking to reticular materials in a new synthetic approach that we call Clip-off Chemistry. We show that bond-breaking in these structures can be controlled at the molecular level; is periodic, quantitative, and selective; is effective in reactions performed in either solid or liquid phases; and can occur in a single-crystal-to-single-crystal fashion involving the entire bulk precursor sample. We validate Clip-off Chemistry by synthesizing two topologically distinct 3D metal-organic frameworks (MOFs) from two reported 3D MOFs, and a metal-organic macrocycle from metal-organic polyhedra (MOP). Clip-off Chemistry opens the door to the programmed disassembly of reticular materials and thus to the design and synthesis of new molecules and materials.
- Broto-Ribas, Anna,Busqué, Félix,Carné-Sánchez, Arnau,Gándara, Felipe,Guillerm, Vincent,Imaz, Inhar,Juanhuix, Judith,Jurado, Sergio,Maspoch, Daniel,Ortín-Rubio, Borja,Yang, Yunhui
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supporting information
(2021/12/09)
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- Photo-induced deep aerobic oxidation of alkyl aromatics
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Oxidation is a major chemical process to produce oxygenated chemicals in both nature and the chemical industry. Presently, the industrial manufacture of benzoic acids and benzene polycarboxylic acids (BPCAs) is mainly based on the deep oxidation of polyalkyl benzene, which is somewhat suffering from environmental and economical disadvantage due to the formation of ozone-depleting MeBr and corrosion hazards of production equipment. In this report, photo-induced deep aerobic oxidation of (poly)alkyl benzene to benzene (poly)carboxylic acids was developed. CeCl3 was proved to be an efficient HAT (hydrogen atom transfer) catalyst in the presence of alcohol as both hydrogen and electron shuttle. Dioxygen (O2) was found as a sole terminal oxidant. In most cases, pure products were easily isolated by simple filtration, implying large-scale implementation advantages. The reaction provides an ideal protocol to produce valuable fine chemicals from naturally abundant petroleum feedstocks. [Figure not available: see fulltext.].
- Wang, Chang-Cheng,Zhang, Guo-Xiang,Zuo, Zhi-Wei,Zeng, Rong,Zhai, Dan-Dan,Liu, Feng,Shi, Zhang-Jie
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p. 1487 - 1492
(2021/07/10)
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- Photoinduced FeCl3-Catalyzed Alkyl Aromatics Oxidation toward Degradation of Polystyrene at Room Temperature?
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While polystyrene is widely used in daily life as a synthetic plastic, the subsequently selective degradation is still very challenging and highly required. Herein, we disclose a highly practical and selective reaction for the catalytically efficient oxidation of alkyl aromatics (including 1°, 2°, and 3° alkyl aromatics) to carboxylic acids. While dioxygen was used as the sole terminal oxidant, this protocol was catalyzed by the inexpensive and readily available ferric compound (FeCl3) with irradiation of visible light (blue LEDs) under only 1 atmosphere of O2 at room temperature. This system could further facilitate the selective degradation of polystyrene to benzoic acid, providing an important and practical tool to generate high-value chemical from abundant polystyrene wastes.
- Zhang, Guoxiang,Zhang, Zongnan,Zeng, Rong
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supporting information
p. 3225 - 3230
(2021/09/28)
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- Preparation method and application of trimellitic acid or trimesic acid
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The invention belongs to the technical field of organic synthesis processes, and particularly relates to a preparation method and application of trimellitic acid or trimesic acid. According to the characteristics of the oxidation reaction process of 1,2,4-trimethylbenzene or mesitylene, two stages of reactors are connected in series, different oxidation reaction process conditions are respectively adopted, particularly, a second-stage reactor adopts a reaction strengthening technology, and an oxygen-enriched oxidation mode is adopted to strengthen the oxidation reaction process and increase the yield of the trimellitic acid or the trimesic acid.
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Paragraph 0040-0047
(2021/04/26)
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- Diazaphosphinyl radical-catalyzed deoxygenation of α-carboxy ketones: A new protocol for chemo-selective C-O bond scission: Via mechanism regulation
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C-O bond cleavage is often a key process in defunctionalization of organic compounds as well as in degradation of natural polymers. However, it seldom occurs regioselectively for different types of C-O bonds under metal-free mild conditions. Here we report a facile chemo-selective cleavage of the α-C-O bonds in α-carboxy ketones by commercially available pinacolborane under the catalysis of diazaphosphinane based on a mechanism switch strategy. This new reaction features high efficiency, low cost and good group-tolerance, and is also amenable to catalytic deprotection of desyl-protected carboxylic acids and amino acids. Mechanistic studies indicated an electron-transfer-initiated radical process, underlining two crucial steps: (1) the initiator azodiisobutyronitrile switches originally hydridic reduction to kinetically more accessible electron reduction; and (2) the catalytic phosphorus species upconverts weakly reducing pinacolborane into strongly reducing diazaphosphinane. This journal is
- Cheng, Jin-Pei,Yang, Jin-Dong,Zhang, Jingjing
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p. 8476 - 8481
(2020/09/07)
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- Method for preparing aromatic carboxylic acid compound
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The invention discloses a method for preparing an aromatic carboxylic acid compound. The method comprises the following steps: 1) heating carbon dioxide and hydrosilane in the presence of a copper catalyst in a reaction medium A; and 2) adding a reaction medium B, aryl halide, a palladium catalyst and a base to the reaction mixture in the step 1), sealing the reaction system, and performing a heating reaction. The method has the advantages that raw materials are simple and easy to obtain, the raw materials are cheap and stable, the catalyst is common, easy to obtain and stable, the reaction conditionsaremild, the aftertreatment is simple, the yield is high, and the like.
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Paragraph 0141-0143; 0159-0161; 0177
(2020/02/14)
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- Tandem one-pot CO2 reduction by PMHS and silyloxycarbonylation of aryl/vinyl halides to access carboxylic acids
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The present study discloses the synthesis of aryl/vinyl carboxylic acids from Csp2-bound halides (Cl, Br, I) in a carbonylative path by using silyl formate (from CO2 and hydrosilane) as an instant CO-surrogate. Hydrosilane provides hydride for reduction and its oxidation product silanol serves as a coupling partner. Mono-, di-, and tri-carboxylic acids were obtained from the corresponding aryl/vinyl halides.
- Paridala, Kumaraswamy,Lu, Sheng-Mei,Wang, Meng-Meng,Li, Can
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supporting information
p. 11574 - 11577
(2018/10/31)
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- Method for preparing trimesic acid
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The invention relate to the field of compound production and preparation, in particular to a method for preparing trimesic acid. The method includes oxidizing 3, 5-dimethylbenzoic acid under the effects of catalytic systems by the aid of liquid-phase oxidation processes to generate the trimesic acid. Compared with the traditional method for preparing trimesic acid from mesitylene which is used as an initial raw material, the method has the advantages that tar substances generated by the 3, 5-dimethylbenzoic acid in reaction procedures are low in content, and accordingly the method is high in yield and favorable for environmental protection and product purification; mother liquor is recycled, accordingly, the utilization rates of various raw materials can be increased, and the productivity can be improved.
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Paragraph 0063-0079
(2017/04/03)
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- A method for producing 3, 5 - dimethyl benzoic acid and trimesitinic acid method
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The invention discloses a method for co-producing 3,5-dimethylbenzoic acid and trimesic acid. The method comprises the steps that mesitylene is taken as raw materials and processed through first-time oxidizing, first-time separating, secondary oxidizing, secondary separating, curing and third-time separating, and then the 3,5-dimethylbenzoic acid and the trimesic acid are obtained. The method has the advantages of being simple in technology, low in cost, high in yield, good in selectivity, green and environmentally friendly.
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Paragraph 0080-0103; 0104-0115; 0116-0125; 0127-0135
(2017/08/31)
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- Aromatic polycarboxylic acid method of manufacturing multi-acyl chloride
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The invention provides a making method for aromatic polycarboxylic acid polyacylchloride, and the method comprises the following procedures: using acylchloride catalyst of chloride or oxide containing Fe or Zn, reacting aromatic polycarboxylic containing sodium under 150 ppm with (trichloromethyl) benzol compound, and obtaining reaction product; and distilling and purifying the reaction product.
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Paragraph 0093; 0094
(2017/03/17)
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- Production Of Terephthalic Acid Via Reductive Coupling Of Propiolic Acid Or Propiolic Acid Derivatives
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A method of making terephthalic acid via reductive coupling of two molecules of propiolic acid or propiolic acid derivatives is presented. The reductive coupling can be catalyzed by compounds comprising metals, and propiolic acid or propiolic acid derivatives can be produced from acetylene and carbon dioxide. At least 4 of the 8 carbons in the terephthalic acid are non-fossil-derived.
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Paragraph 0036; 0037
(2016/10/04)
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- Inclusion complex containing epoxy resin composition for semiconductor encapsulation
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The invention is an epoxy resin composition for sealing a semiconductor, including (A) an epoxy resin and (B) a clathrate complex. The clathrate complex is one of (b1) an aromatic carboxylic acid compound, and (b2) at least one imidazole compound represented by formula (II): wherein R2 represents a hydrogen atom, C1-C10 alkyl group, phenyl group, benzyl group or cyanoethyl group, and R3 to R5 represent a hydrogen atom, nitro group, halogen atom, C1-C20 alkyl group, phenyl group, benzyl group, hydroxymethyl group or C1-C20 acyl group. The composition has improved storage stability, retains flowability when sealing, and achieves an effective curing rate applicable for sealing delicate semiconductors.
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- A one-pot, three-component synthesis of spiro[indoline-isoxazolo[40,30:5,6] pyrido [2,3-d]pyrimidine]triones in water
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A one-pot, three-component condensation reaction of an isatin, isoxazole, and barbituric acid in water to give spirooxindoles in high yields, at 70°C temperature, using a catalytic amount of p-toluene sulfonic acid, is described.
- Rahmati, Abbas,Khalesi, Zahra
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experimental part
p. 8472 - 8479
(2012/09/25)
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- Design of protonated polyazamacrocycles based on phenanthroline motifs for selective uptake of aromatic carboxylate anions and herbicides
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Three novel large polyazamacrocycles containing two 1,10-phenanthroline (phen) units connected by two polyamine spacers of different length, [32]phen2N4, [30]phen2N6 and Me 2[34]phen2N6, have been synthesised and their protonated forms used as receptors for binding studies with several aromatic carboxylate anions (benzoate (bzc-), 1-naphthalate (naphc -), 9-anthracenate (anthc-), pyrene-1-carboxyl-ate (pyrc-), phthalate, (ph2-), isophthalate (iph 2-), terephthalate (tph2-), 2,5-dihydroxy-1,4- benzenediacetate (dihyac2-) and, 1,3,5-benzenetricarboxylate (btc3-)) and three herbicides (4-amino-3,5,6-trichloropyridine-2- carbox-ylate (ATCP-), dichlorophenoxyacetate (2,4-D-) and glyphosate (PMG2-)) in water solution. The [30]phen2N 6 receptor was found to be the most suitable for binding the anions considered in a 1:1 stoichiometry. The three receptors exhibit a remarkable binding selectivity towards the extended aromatic anion pyre- at low pH values. Their binding affinities for the monocarboxylate anions decrease with the extension of the aromatic system in the order pyre- > anthc- > naphc- > bzc-, which indicates the presence of π-π stacking interactions in the molecular recognition of these anions. Molecular dynamics simulations carried out for the binding of (H4[30]phen2N6}4+ and {H 6Me2[34]phen2N6}6+ with pyre-, anthc-, naphc-, iph2- and btc3- in water showed that these receptors adopt a folded conformation with the anion inserted between the two phen heads and that the molecular recognition is governed by π-π stacking interactions and multiple N-H...O=C hydrogen bonds. The binding free energies estimated theoretically are very similar to those found by Potentiometric methods, which supports the proposed binding arrangement.
- Cruz, Carla,Cahsto, Vania,Delgado, Rita,Felix, Vitor
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supporting information; scheme or table
p. 3277 - 3289
(2009/12/05)
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- Aerobic oxidation of trimethylbenzenes catalyzed by N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst
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The oxidation of trimethylbenzenes was examined with air or O2 using N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst. Thus, 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes under air (20 atm) in the presence of THICA (5 mol %), Co(OAc)2 (0.5 mol %), Mn(OAc)2, and ZrO(OAc)2 at 150 °C were oxidized to the corresponding benzenetricarboxylic acids in good yields (81-97%). In the aerobic oxidation of 1,2,4-trimethylbenzene by the THICA/Co(II)/Mn(II) system, remarkable acceleration was observed by adding a very small amount of ZrO(OAc)2 to the reaction system to form 1,2,4-benzenetricarboxylic acid in excellent yield (97%). In contrast, no considerable addition effect was observed in the oxidation of 1,3,5-trimethylbenzene. This aerobic oxidation by the present catalytic system provides an economical and environmentally benign direct method to benzenetricarboxylic acids, which are very important polymer materials.
- Hirai, Naruhisa,Tatsukawa, Yoshinobu,Kameda, Michiko,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 6695 - 6699
(2007/10/03)
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- Is it possible to achieve highly selective oxidations in supercritical water? Aerobic oxidation of methylaromatic compounds
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We have demonstrated that different methylaromatic compounds [1,4-dimethylbenzene (p-xylene), 1,3-dimethylbenzene (m-xylene), 1,2-dimethylbenzene (o-xylene), 1,3,5-trimethylbenzene (mesitylene) and 1,2,4-trimethylbenzene (pseudocumene)] can be aerobically oxidized in supercritical water (scH2O) using manganese(II) bromide as catalyst to give corresponding carboxylic acids in the continuous mode over a sustained period of time in good yield. No partially oxidized intermediates (i.e., toluic acid and benzaldehydes) were detected for the dimethylbenzenes and mesitylene reactions. By fine tuning pressure and temperature, ScH2O becomes a solvent with physical properties suitable for single-phase oxidation since both organic substrate and oxygen are soluble in scH2O. There is a strong structural similarity of metal/bromide coordination compounds in the active oxidation solvents (acetic acid and scH2O) which does not exist in the much less active H2O at lower temperatures. This may account for the successful catalysis of the reactions reported herein. Aromatic acids produced by the loss of one methyl group occurred in all of these reactions, i.e., 3-6percent benzoic acid formed during the oxidation of the dimethylbenzenes. Part of this loss is thought to be due to thermal decarboxylation. The thermal decarboxylation process is monitored via Raman spectroscopy.
- Garcia-Verdugo, Eduardo,Venardou, Eleni,Barry Thomas,Whiston, Keith,Partenheimer, Walter,Hamley, Paul A.,Poliakoff, Martyn
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p. 307 - 316
(2007/10/03)
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- Multivalent neuraminidase inhibitor conjugates
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The invention relates to a multimeric compound or a pharmaceutically acceptable salt or derivative thereof which comprises three or more neuraminidase-binding groups attached to a spacer or linking group, in which the neuraminidase-binding group is a compound which binds to the active site of influenza virus neuraminidase, but is not cleaved by the neuraminidase. The invention also relates to processes for the preparation of the multimeric compound defined above, pharmaceutical compositions containing them or methods for the treatment and/or prophylaxis of a viral infection involving them.
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- Naaladase inhibitors for treating retinal disorders and glaucoma
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The present invention relates to pharmaceutical compositions and methods for treating a retinal disorder or glaucoma using NAALADase inhibitors.
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- Naaladase inhibitors for treating amyotrophic lateral sclerosis
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The present invention relates to pharmaceutical compositions and methods for treating amyotrophic lateral sclerosis using NAALADase inhibitors.
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- Benzenedicarboxylic acid derivatives
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New benzenedicarboxylic acid derivative compounds; pharmaceutical compositions, diagnostic methods, and diagnstic kits that include those compounds; and methods of using those compounds for inhibiting NAALADase enzyme activity, detecting diseases where NAALADase levels are altered, effecting neuronal activity, effecting TGF-β activity, inhibiting angiogenesis, and treating glutamate abnormalities, neutopathy, pain, compulsive disorders, prostate diseases, cancers, and glaucoma.
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- Smooth muscle cell proliferation inhibitors
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This invention comprises polyanionic benzylglycosides of benzene triacid amides of the general formula I STR1 wherein each of R1, R2, R3, and R4 are, independently, H, SO3 M, or STR2 and each oligosaccharide group contains 1 to 3 sugar groups; M is lithium, sodium, potassium, or ammonium; n is 1 or 2; X is a halogen, lower alkyl having 1 to 6 carbon atoms, or lower alkoxy having 1 to 6 carbon atoms; Y is carbonyl or sulfonyl; or the pharmaceutically acceptable salts thereof, as well as their use as smooth muscle cell antiproliferation inhibitors and as therapeutic compositions for treating diseases and conditions which are characterized by excessive smooth muscle proliferation.
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- Iodinated aroyloxy ketones
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Compounds having the structure STR1 wherein (Z--COO is the residue of an iodinated aromatic acid; n is an integer from 0 to 20; R1, R2, R3 and R4 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy, aryloxy, halogen, hydroxy, acylamino, acetamidoalkyl, acetamidoaryl, --COO-alkyl, --COO-aryl, --COO-aralkyl, --CO-alkyl, --CO-aryl, --CO-heterocyclyl, cyano or heterocyclyl; R5 is H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, heterocyclyl, or a Z-CO2 -CR1 R2 (CR3 R4)n group, wherein Z, R1, R2, R3, R4 and n are as defined above, m is an integer from 0 to 10, p is an integer from 0 to 10, and m+p≥1 are useful as contrast agents in x-ray imaging compositions and methods.
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- Iodinated aromatic compounds
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Compounds having the structure STR1 wherein (Z--COO is the residue of an iodinated aromatic acid; n is an integer from 0 to 6; R1 and R2 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy or aryloxy; R3 and R4 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy, aryloxy, halogen, hydroxy or acylamino; Q represents the atoms necessary to complete a carbocyclic or heterocyclic unsaturated mono- or bicyclic aromatic ring; and R5 is H, alkyl, cycloalkyl, aryl, aralkyl, alkoxy, aryloxy, halogen, hydroxy, amino, acylamino, alkoxyalkyl, fluoroalkyl, acetamidoalkyl, COO-alkyl, cyano, carboxamido, sulfonate, sulfonamido, ureido, or carbamyl are useful as contrast agents in x-ray imaging compositions and methods.
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- Iodinated benzoyl acetals and ketals for x-ray imaging
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Compounds having the structure STR1 wherein (Z--COO is the residue of an iodinated aromatic acid; R is alkyl, cycloalkyl, aryl, aralkyl, STR2 or alkenyl; R1 is H, alkyl, cycloalkyl, aryl, aralkyl, or --CH2 --m CO2 R3 ; R2 is H, alkyl, cycloalkyl, aryl, aralkyl, --CH2 --n CO2 R4, or a STR3 group, wherein Z, R and R1 are as defined above; or R1 and R2, taken together with the carbon atom to which they are attached represent cycloalkyl; R3 is H, alkyl, cycloalkyl, aryl or aralkyl; R4 is H, alkyl, cycloalkyl, aryl or aralkyl; and m, n and p are independently an integer of from 0 to 17; provided that R1 and R2 can not both be H; are useful in the preparation of x-ray contrast compositions for medical imaging.
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- Iodinated wetting agents
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Compounds having the structure STR1 wherein (Z)--COO is the residue of an iodinated aromatic acid; M is H, a cation, --CH2 CH2 O--m H, and --CH2 CH(OH)O--p H; m is an integer from 1 to 150; p is an integer from 1 to 50; and L is one or more divalent linking groups selected from alkylene, cycloalkylene, arylene, arylenealkylene, and alkylenearylene are particularly useful as wetting agents in x-ray imaging compositions.
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- Iodinated aroyloxy esters
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Compounds having the structure STR1 wherein (Z--COO is the residue of an iodinated aromatic acid; n is an integer from 1 to 20; R1 and R2 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy or aryloxy; R3 and R4 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy, aryloxy, halogen, hydroxy or acylamino; and R5 is alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl or acetamidoalkyl; are useful as contrast agents in x-ray imaging compositions and methods.
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- Iodinated aromatic propanedioates
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Compounds having the structure STR1 where (Z--COO is the residue of an iodinated aromatic acid; R1 and R2 are independently alkyl, fluoroalkyl, cycloalkyl, aryl or aralkyl; and R3 is H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy, aryloxy, cyano, sulfonate, carboxamido, sulfonamido, CO2 -alkyl, CO2 -aryl or CO2 -aralkyl; are useful as contrast agents in x-ray imaging compositions and methods.
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- Iodinated aroyloxy carboxamides
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Compounds having the structure STR1 wherein (Z--COO is the residue of an iodinated aromatic acid; n is an integer from 0 to 20; R1 and R2 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy or aryloxy; R3 and R4 are independently a substituent as defined for R1 and R2 above, halogen, hydroxy or acylamino; and R5 and R6 are independently H, alkyl, cycloalkyl, aryl, aralkyl, alkoxy, alkoxyalkyl, or acetamidoalkyl; or R5 and R6, taken together with the nitrogen atom to which they are attached, represent a 4 to 7-membered nitrogen containing ring, are useful as contrast agents in x-ray imaging compositions and methods.
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- Cobalt Salts-Catalyzed Carbonylation of Aromatic Halides under Photostimulation
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A novel method for the carbonylation of aromatic halides by the cobalt salt catalysts such as Co(OAc)2*4H2O, CoCl2*6H2O, CoSO4*7H2O, Co(OH)2, Co(OH)3, CoO, and Co2O3 was investigated in an aqueous alkaline solution under photostimulation.These salts were found to have a catalytic activity as high as that of Co2(CO)8 under mild conditions.
- Kudo, Kiyoshi,Shibata, Tadashi,Kashimura, Tsugunori,Mori, Sadayuki,Sugita, Nobuyuki
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p. 577 - 580
(2007/10/02)
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- COBALT CARBONYL CATALYZED POLYCARBONYLATION OF POLYHALOGENATED AROMATICS UNDER PHOTOSTIMULATION
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Cobalt carbonyl catalyzed polycarbonylation of much less reactive polychlorobenzenes could be easily achieved under photostimulation in aqueous sodium hydroxide.All these reactions could be performed without any organic solvent(in some cases, ethanol was used as a co-solvent) and any phase transfer catalyst.
- Kashimura, Tsugunori,Kudo, Kiyoshi,Mori, Sadayuki,Sugita, Nobuyuki
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p. 299 - 302
(2007/10/02)
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- OXIDATION OF ALKYL AROMATIC COMPOUNDS WITH POTASSIUM PERMANGANATE UNDER THE CONDITIONS OF INTERPHASE CATALYSIS
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A new method is proposed for the synthesis of benzenecarboxylic acids by oxidation of toluene, p-xylene, mesitylene, and durene with potassium permanganate in a two-phase system of hydrocarbon and water at 70-90 deg C with quaternary ammonium salts as catalysts of interphase transfer.When cetyltrimethylammonium bromide is used as catalyst benzoic, terephthalic, trimesic, and pyromellitic acids are formed with yields close to quantitative.A reaction mechanism is proposed.The effect of various factors on the reaction rate and on the product yields was investigated.
- Artamkina, G. A.,Grinfel'd, A. A.,Beletskaya, I. P.
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p. 612 - 615
(2007/10/02)
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- INFLUENCE OF NITROGEN LIGANDS ON SYNERGIC EFFECT OF METAL CATALYSTS IN OXYDATION OF ALKYLAROMATIC COMPOUNDS
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Synergic effect of metal mixtures Co-Mn, Co-Ce and Co-U in oxidation of 1,2,4- and 1,3,5-trimethylbenzenes dissolved in acetic acid has been studied in dependence of the presence of nitrogen ligands 2,2',2''-nitrilotrisethanol, 1,6-hexanediamine and pyridine.The complex CoBr2Py2 and its equimolar mixture with the complex MnBr2Py2 are highly active in oxidation of alkylaromatic derivatives containing other alkyl than methyl.Their activity has been tested experimentally in oxidations of ethylbenzene, 1,3- and 1,2-dimethylbenzenes, 1-ethyl-4-methylbenzene, (1-methylethyl)benzene, propylbenzene, 1-methyl-4-(1-methylethyl)benzene, dodecylbenzene, 1,3-diethylbenzene and 4-octyl-1,1'-biphenyl
- Hronec, Milan,Holotik, Stefan,Ilavsky, Jan
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p. 880 - 887
(2007/10/02)
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- STUDY OF STRUCTURE AND ACTIVITY OF COBALT BROMIDE COMPLEXES IN THE OXIDATION OF ALKYLAROMATIC HYDROCARBONS
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Catalytic activity of tetrabromocobalt(II) complexes and halo complexes of the type CoX2L2 respectively with ligands involving as donor atom, nitrogen, sulphur, phosphorus, arsenic, or antimony was studied in oxidation of alkylaromatic hydrocarbons.The participitation of the nitrogen compounds in the complex formation and in the elementary reaction stages was investigated.Highly catalytically active are tetrahedral complexes of the type CoBr4(2-) and (CoBr3OAc)(2-).Triethanolamine-coordinated cobalt bromide and chloride complexes react in acetic acid or its anhydride with oxygen, the triethanolamine ligand being oxidized as well.In addition to their participitation in the cobalt complex formation, nitrogen compounds influence the recovery of the active forms of the catalyst; they do not, however, affect the rate of dehalogenation of organic bromides.
- Hronec, Milan
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p. 1555 - 1566
(2007/10/02)
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