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Product patterns can be altered in reactions of m-nitrobenzotrichloride [VI] with [AHF]x·NH4F complex. Side-chain fluorination predominates under ‘mild’ conditions. In contrast. ‘forcing’ conditions affected unexpected in-situ fluorination-reduction to give m-aminobenzotrifluoride [V] in high yield [75%] and purity [99.6%]. in-situ reduction is probably initiated by a combination of iron from the stainless steel autoclave and trace amounts of moisture. The transformation of [VI] to [V] represents another type of in-situ fluorination-reduction nitroaromatics, e.g. nitrobenzene [VII] to p-fluoroaniline [VIII]. o-Nitrobenzotrichloride [XI] degraded under ‘forcing’ conditions with [AHF]x·NH4F.  相似文献   

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《Chemical physics letters》2006,417(1-3):39-42
The formaldehyde–sulfite reaction is an acid to alkali clock reaction in batch, which displays complex behaviour in a flow reactor. Current published mechanisms do not account for the behaviour in an open system. In this Letter, we construct a minimal model based on this system and demonstrate that a base-catalysed rate-determining step coupled with an appropriate OH consuming reaction can result in bistability and oscillations. The model may provide a method for the design of organic-based pH oscillators.  相似文献   

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A reaction of a lithiated derivative of 4,4,5,5-tetramethyl-3-oxido-4,5-dihydro-1H-imidazole 1-oxyl with 3,6-di-tert-butyl-o-benzoquinone at ?80 °C predominantly gave spin-labeled dihydrooxepine via nucleophilic 1,2-addition of the paramagnetic carbanion to the CO group of the benzoquinone followed by insertion of the O atom into the ring. At lower temperatures, this reaction was accompanied by 1,4-addition of the organolithium compound to the benzoquinone followed by oxidation of the resulting adduct into spin-labeled o-benzoquinone. This ??one pot?? process is a novel approach to organic derivatives that can further be converted into di- and polyradicals combining nitronyl nitroxide and semiquinolate fragments.  相似文献   

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A method is described to couple sterically-hindered electron-poor anilines to the 4-position of the pyrimidine core using a pyrimidine-2,4-bis(trifluoromethanesulfonate).  相似文献   

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A series of novel 10-deoxoartemisinin derivatives was synthesized with high regioselectivity and yields using Heck reactions from 10β-allyldeoxoartemisinin. The configuration of the double bond of the product was determined from 1H NMR coupling constants (J2′-3′).  相似文献   

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Runcie KA  Taylor RJ 《Organic letters》2001,3(21):3237-3239
[structure: see text]. Several novel scyphostatin analogues have been prepared in up to 18% yield over five steps from commercially available 4-bromoguaiacol, utilizing an organometallic addition to afford the desired syn-hydroxy-epoxides.  相似文献   

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Base-promoted reaction of dimethyl diazomethylphosphonate (1) with dialkyl and cyclic ketones in the presence of alcohols and of amines affords aldehydic enol ethers and enamines, respectively.  相似文献   

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The reaction between 3‐amino‐2,3‐dihydro‐7,9‐dimethyl‐2‐thioxo‐pyrido[3′,2′:4,5]thieno[3,2‐d]‐pyrimidin‐4(1H)‐one 4 or its 2‐methylthio derivative 5 with hydrazonoyl halides 6 in dioxane in the presence of triethylamine under reflux has followed heterocyclization reaction to yield pyrido[3″,2″:4′,5′]‐thieno[3′,2′:4,5]pyrimido[2,1‐c][1,2,4,5]tetrazin‐6(4H)‐ones 9 . On the other hand, reaction of compound 4 with hydrazonoyl halides 6 in sodium ethoxide at room temperature led to formation of hydrazonothioate compounds 10 . The latter on treatment with glacial acetic acid produced tetracyclic compounds, namely 2‐arylhydrazonopyrido[3″,2″:4′,5′]thieno [3′,2′:4,5]pyrimido[2,1‐b][1,3,4]thiadiazinones 11 . An alternative method was carried out to prove the structure of product 11 . The mechanism of the reaction under study was proposed and the products were screened for their biological activity.  相似文献   

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A novel one-step synthesis route to fully substituted pyrazol-4-ols is reported. This simple yet nonobvious method for the construction of pyrazol-4-ols by the condensation-fragmentation-cyclization-extrusion reactions of thietanones with 1,2,4,5-tetrazines is reported. All of the elements of the thietanone except its sulfur are incorporated in these novel products.  相似文献   

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A white substance was got by directly heating TiSi powder on Ti foil, under Ar+O2 atmosphere. ED, EDX, SEM and HRTEM studies reveal that the white substance consists of amorphous SiO2nanowires of smooth surface and uniform diameter (40-90 nm). X-ray-induced luminescent emission experiment shows that two broad peaks are at 430 and 570 nm. A one-dimensional growth mechanism, on the basis of the one-dimensional thermal flow during nanowire formation, is discussed.  相似文献   

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The synthesis and X-ray structural determination of vinylogous tetrathiafulvalenes (TTFV) bearing functional groups on the central conjugation are reported. An unexpected evolution of the bis hydroxymethyl TTFV leading to a derivative, which acts simultaneously as a diene and a dienophile in a Diels-Alder reaction is also described.  相似文献   

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Blends of natural and synthetic polymers were studied for potential applications in the biomedical field. Collagen and hyaluronic acid were mixed in aqueous solution with poly(vinyl alcohol) and poly(acrylic acid). The properties of the blends were studied by differential scanning calorimetry and dynamic mechanical thermal analysis. Some methods were also investigated to enhance the miscibility of the polymers in these blends.  相似文献   

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[reaction--see text] Dimerization of salicylaldehydes provided 6H,12H-6,12-epoxydibenzo[b, f][1,5]dioxocins in multigram quantities. Deprotonation-allylation of the benzylic acetals followed by further functionalization of the diallyl derivative and double Friedel-Crafts cyclization gave a novel preussomerin analogue which possessed the full carbon skeleton of the natural products.  相似文献   

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2-Bromo-3,4-dicyanopyridine 2 was obtained in moderate yield by reacting 1,1,2,2-tetracyano-3-trimethylsiloxycyclobutane 1 with phosphorus tribromide. Similarly, reaction of 1 with chlorinating reagents such as thionyl chloride and oxalyl chloride led to the corresponding 2-chloro-3,4-dicyanopyridine 3 in 40% yield. A reaction mechanism is suggested.  相似文献   

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