- Electro-Oxidative Selective Esterification of Methylarenes and Benzaldehydes
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A mild and green electro-oxidative protocol to construct aromatic esters from methylarenes and alcohols is herein reported. Importantly, the reaction is free of metals, chemical oxidants, bases, acids, and operates at room temperature. Moreover, the design of the electrolyte was found critical for the oxidation state and structure of the coupling products, a rarely documented effect. This electro-oxidative coupling process also displays exceptional tolerance of many fragile easily oxidized functional groups such as hydroxy, aldehyde, olefin, alkyne, as well as neighboring benzylic positions. The enantiomeric enrichment of some chiral alcohols is moreover preserved during this electro-oxidative coupling reaction, making it overall a promising synthetic tool.
- Yu, Congjun,?zkaya, Bünyamin,Patureau, Frederic W.
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supporting information
p. 3682 - 3687
(2021/02/01)
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- [OONN] tetradentate fourth subgroup metal complexes as well as preparation method and application thereof
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The invention relates to the technical field of olefin polymerization catalysts, and particularly discloses [OONN] tetradentate fourth subgroup metal complexes, a preparation method and application. The [OONN] tetradentate fourth subgroup metal complexes have a structure which is shown in the specification. The [OONN] tetradentate fourth subgroup metal complexes provided by the invention can catalyze ethylene polymerization and ethylene and alpha-olefin copolymerization, and in the polymerization process, the heat resistance is good, and the polymerization time is long. The complexes are simple in synthesis method, easy to prepare and high in yield, the structure is convenient to modify, the complexes can be used for catalyzing ethylene polymerization and ethylene and alpha-olefin copolymerization after being activated by a proper cocatalyst, the problems that an existing olefin polymerization catalyst is relatively tedious in preparation process, high in cost and low in catalytic activity are solved, and the complexes have good industrial application value and wide application field.
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Paragraph 0032-0035
(2021/05/12)
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- Preparation method of nitrogen-alkyl (deuterated alkyl) aromatic heterocycle and alkyl (deuterated alkyl) aryl ether compound
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The invention provides a method for preparing nitrogen-alkyl(deuterated alkyl)aromatic heterocycle and alkyl(deuterated alkyl)aryl ether compounds. The method adopted in the invention specifically comprises the following steps: firstly, adding an alkoxy base (MOR') or a combination reagent Q (comprising a base M'X, an alcohol C and a molecular sieve E) into a solvent B to be stirred; then, addingan aromatic compound D of nitrogen sulfonyl or oxygen sulfonyl into a mixture; separating and purifying after reaction to obtain nitrogen-alkyl(deuterated alkyl)aromatic heterocycle or alkyl(deuterated alkyl)aryl ether. The method can realize one-step conversion from an electron withdrawing benzenesulfonyl protecting group on a nitrogen or oxygen atom to an electron donating alkyl protecting group, avoids using highly toxic alkyl halide, and has advantages of being efficient, economical, environmentally friendly, mild in condition, good in substrate universality and high in yield; the prepareddeuterated compounds can be widely applied to the fields of pharmaceutical chemistry and organic chemistry synthesis.
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Paragraph 0093-0098
(2021/04/03)
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- Synthesis and in vitro activities on anti-platelet aggregation of 4-methoxy-1,3-phthalamidesamides and benzenedisulfonamides
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Cardiovascular diseases are the most frequent cause of morbidity and mortality worldwide. In order to discover novel compounds with anti-platelet aggregation activities, a series of novel 4-methoxy-1,3-phthalamidesamides (1a–1i) and a series of novel 4-methoxy-1,3-benzenedisulfon-amides (2a–2i) were synthesized and their anti-platelet aggregation activities were evaluated by the turbidimetric method in response to the following agonists: adenosine diphosphate (ADP), arachidonic acid (AA), and Collagen. Those compounds that have better in vitro activities were subjected to cell toxicity tests via cell counting kit-8 (CCK-8) assay. The inhibition rates of anti-platelet in vitro of five compounds 1g (39.45%), 2d (38.87%), 2g (38.55%), 2h (44.56%), and 2i (43.93%) were higher than that of two reference drugs picotamide (36.12%) and aspirin (38.45%) when ADP was selected as an inducer. The inhibition rates of seven compounds 1c (43.63%), 1d (40.02%), 1g (47.42%), 1i (40.45%), 2c (40.11%), 2d (40.45%), and 2i (49.05%) were higher than that of picotamide (34.89%) and aspirin (39.43%) when AA was selected as inducer. And the inhibition rates of five compounds 1d (47.22%), 1i (45.01%), 2d (38.74%), 2e (42.21%), and 2f (39.94%) were higher than picotamide (38.45%) and aspirin (37.08%) when collagen was selected as inducer. Moreover, the effect of cell toxicity exhibited that none of the compounds had obvious cell toxicity against L-929 cells. Therefore, 4-methoxy-1,3-phthalamidesamides (1a–1i) and 4-methoxy-1,3-benzenedisulfon-amides (2a–2i) have the potential to become a novel kind of anti-platelet drugs and deserve further study.
- Chen, Guangling,Wang, Chaoqing,Zhang, Zhihao,Liu, Xiujie
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p. 1413 - 1424
(2019/06/20)
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- Detosylative (Deutero)alkylation of Indoles and Phenols with (Deutero)alkoxides
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An efficient strategy for N/O-(deutero)alkylation of indoles and phenols with alkoxides/alcohols as the alkylation reagents is described. The consecutive detosylation/alkylation transformations feature mild reaction conditions, high ipso-selectivity, and good functional group tolerance (>50 examples). A one-pot selective N-alkylation of unprotected indoles with alcohols and TsCl is also realized. The application of this method is demonstrated by the introduction of isotope-labeled (CD3 and 13CH3) groups using the readily accessible labeled alcohols and the synthesis of pharmaceuticals.
- Zhu, Ming-Hui,Yu, Cheng-Long,Feng, Ya-Lan,Usman, Muhammad,Zhong, Dayou,Wang, Xin,Nesnas, Nasri,Liu, Wen-Bo
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supporting information
p. 7073 - 7077
(2019/09/30)
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- 4,5-Dimethyl-2-Iodoxybenzenesulfonic Acid Catalyzed Site-Selective Oxidation of 2-Substituted Phenols to 1,2-Quinols
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A site-selective hydroxylative dearomatization of 2-substituted phenols to either 1,2-benzoquinols or their cyclodimers, catalyzed by 4,5-dimethyl-2-iodoxybenzenesulfonic acid with Oxone, has been developed. Natural products such as biscarvacrol and lacinilene C methyl ether could be synthesized efficiently under mild reaction conditions. Furthermore, both the reaction rate and site selectivity could be further improved by the introduction of a trialkylsilylmethyl substituent at the 2-position of phenols. The corresponding 1,2-quinols could be transformed into various useful structural motifs by [4+2] cycloaddition cascade reactions.
- Uyanik, Muhammet,Mutsuga, Tatsuya,Ishihara, Kazuaki
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supporting information
p. 3956 - 3960
(2017/03/27)
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- DEUTERATED BENZOPYRAN COMPOUND AND APPLICATION THEREOF
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features as shown in Formula (I), or pharmaceutically acceptable salts or stereoisomers thereof, or prodrug molecules thereof. With excellent anti-inflammatory and analgesic effects and the capability to inhibit growth of tumor cells, such compounds are novel COX-2 selective inhibitors. The compounds and pharmaceutically acceptable salts thereof disclosed by the present application can be applied in preparing anti-inflammatory and analgesic drugs and drugs for treating or preventing tumors.
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Paragraph 0188-0189
(2015/03/18)
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- Deuterated Benzopyran Compounds and Application Thereof
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The present invention discloses deuterated benzopyran compounds having structure features as shown in Formula (I), or pharmaceutically acceptable salts or stereoisomers thereof, or prodrug molecules thereof. With excellent anti-inflammatory and analgesic effects and the capability to inhibit growth of tumor cells, such compounds are novel COX-2 selective inhibitors. The compounds and pharmaceutically acceptable salts thereof disclosed by the present application can be applied in preparing anti-inflammatory and analgesic drugs and drugs for treating or preventing tumors.
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Paragraph 0295; 0296; 0297; 0298
(2015/05/26)
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- Improved Protocol for Mononitration of Phenols with Bismuth(III) and Iron(III) Nitrates
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A simple and efficient multigram procedure was developed for the selective mononitration of various activated phenols. The reaction proceeded smoothly with 0.5 equivalents of Bi(NO3)3 · 5H2O or Fe(NO3)3 · 9H2O in acetone at ambient temperature or at reflux. The desired products were isolated in 62-93% total yield and essentially no overnitrated compounds were detected.
- W?sińska, Ma?gorzata,Korczewska, Anna,Giurg, Miros?aw,Skarzewski, Jacek
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supporting information
p. 143 - 150
(2015/10/20)
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- NEW PROCESSES FOR PREPARING 4-SUBSTITUTED IMIDAZOLES
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There is provided a novel process for the preparation of a compound of formula (I), (Formula (I)). There is also provided novel processes to intermediates of the compound of formula (I), as well as novel intermediates themselves.
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Page/Page column 40
(2013/03/26)
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- Synthesis of aryl alkyl ethers by alkylation of phenols with quaternary ammonium salts
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Phenolic compounds can be efficiently O-methylated with tetramethylammonium chloride in diglyme or polyethyleneglycol (PEG) at temperatures of 150-160 °C and in the presence of either K2CO3 or NaOH. When applying benzyl-trimethylammonium chloride as a reagent, the benzylation and methylation of phenols occurs, with the benzylation product always predominating. With allyl-substituted phenols as substrates and using NaOH as a base it was possible to achieve both the alkylation and the double-bond isomerization of the allyl group to obtain (E/Z)-propenyl-substituted methyl and benzyl aryl ethers in a single preparative step.
- Maras, Nenad,Polanc, Slovenko,Kocevar, Marijan
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experimental part
p. 29 - 36
(2010/09/05)
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- The role of ion-molecule pair intermediates in acid-catalyzed solvolysis. General base-catalyzed formation of 4-methylbenzyl carbocation and its trapping by nucleophiles
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The specific acid-catalyzed hydrolysis of 3,6-dimethoxy-3,6-dimethyl-1,4- cyclohexadiene (1) in 25 vol % acetonitrile in water at 25 °C provides 2,4- dimethylphenol (2a), 2,5-dimethylphenol (2b), 2,4-dimethylanisole (3a), 4- methylbenzyl alcohol (4), and small amounts of 2,5-dimethylanisole (3b) and 4-methylbenzyl methyl ether (5). The formation of 3b and 5 is proposed to involve intramolecular rearrangement of carbocation-molecule pair intermediates. The formation of 4-methylbenzyl alcohol (4) is catalyzed by general bases, indicating that dehydronation of the cyclohexadienyl carbocation is rate-limiting in its reaction to benzylic products. The Bronsted parameter was measured with carboxylate anions as β = 0.28. The 4- methylbenzyl carbocation, which is postulated to be an intermediate in this reaction, discriminates between added nucleophiles and solvent water: k(SCN)/k(HOH) = 37, k(Cl)/K(HOH) = 9.8, k(EtOH)/k(HOH) = 1.9, and k(MeOH)/k(HOH) = 2.1 (ratios of second-order rate constants). The rate constant for reaction of the carbocation with solvent water is estimated as k(HOH) = 1.4 x 108 M-1s-1 (5.6 x 109 s-1), assuming a diffusion- controlled rate constant of 5 x 109 M-1s-1 for its reaction with thiocyanate anion. The nucleophilic selectivity values are considerably smaller than those exhibited by 4-methylbenzyl bromide under the same reaction conditions: k(Cl)/k(HOH) = 210, k(EtOH)/k(HOH) = 3.8, and k(MeOH)/k(HOH) = 5.3. These differences are concluded to be due to different mechanisms. The bromide reacts by a concerted bimolecular S(N)2 mechanism with chloride anion. With alcohols and water, the reactions occur either by a concerted uncoupled mechanism or via the ion pairs.
- Thibblin
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p. 7427 - 7433
(2007/10/02)
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- Easy synthesis of 2,4-dialkyl substituted phenols and anisoles from p-benzoquinone
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The reaction of p-benzoquinone (1) with several organolithium compounds (methyl-, ethyl-, n-butyl, phenyllithium) leads directly, after acid hydrolysis, to the corresponding 2,4-dialkylphenols 4a-d, resulting from a rearrangement/aromatization process of the corresponding intermediate diols 3. The use of two different alkyllithium reagents leads to the mixed products 4e f. Alternatively, the same results are obtained treating the crude isolated diols 3 with a catalytic amount of concentrated sulfuric acid. Applying this last methodology to the diethers 2, 2,4-dialkylanisoles 8 are obtained. A possible mechanism is proposed.
- Alonso,Yus
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p. 2709 - 2714
(2007/10/02)
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- EFFECT OF MODIFICATION OF ZEOLITE CATALYSTS ON THEIR ACIDITY AND CATALYTIC ACTIVITY IN THE VAPOR-PHASE ALKYLATION OF PHENOL BY METHANOL
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A study has been made of a series of zeolite catalysts modified with lanthanum and magnesium oxides, the additives being introduced into the zeolite by different methods.It has been established that the most active catalysts are those modified by ion exchange.It is concluded that the alkylation of phenol by methanol proceeds mainly inside the zeolite pores and involves at least two types of acid centers.
- Ponomarenko, I. Yu.,Koval, L. M.
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p. 1888 - 1892
(2007/10/02)
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- Process for the manufacture of fluoran compounds
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A process for the preparation of a fluoran compound of the formula STR1 wherein R, R1, R2 and R4 are each independently hydrogen, halogen, lower alkyl or lower alkoxy, R3 is hydrogen, halogen, lower alkyl, lower alkoxy or --NX3 X4, or (R1 and R2) or (R3 and R4) each pair together with the carbon atoms to which they are attached, form a fused benzene nucleus, X1, X2, X3 and X4 are each independently hydrogen, alkyl containing not more than 12 carbon atoms which is unsubstituted or substituted by cyano, halogen, hydroxy, tetrahydrofuryl or lower alkoxy, or are cycloalkyl, aryl or aralkyl or (X1 and X2) or (X3 and X4) are each independently together with the nitrogen to which are attached a 5- or 6-membered heterocyclic ring, and the ring A is unsubstituted or substituted by halogen, nitro, lower alkyl, lower alkylthio, lower alkoxy, lower alkoxycarbonyl, amino, mono-lower alkylamino, di-lower alkylamino or lower alkyl carbonylamino, which process comprises (1) reacting a ketonic acid of the formula STR2 with a substituted phenol derivative of the formula STR3 wherein Z is hydrogen, lower alkyl, formyl or lower alkanoyl and A, R, R1, R2, R3, R4, X1 and X2 have the given meanings, (2) adding the reaction product to an aqueous-organic liquor containing a non-polar organic solvent and a base at a temperature of 50° to 90° C., (3) separating the organic phase and (4) removing the organic solvent to obtain the fluoran of the formula (1).
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- METALATION REACTIONS. XIV. REGIOSPECIFIC PREPARATION OF POLYSUBSTITUTED BENZENES VIA MONO- OR DI-LITHIATION REACTIONS OF AROMATIC THIOETHERS
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The preparation of polyfunctionalized aromatic thioethers either by one-step dilithiation or by two successive one-flask monometalation reactions is described.By acting on 1 two equal or different electrophiles one on the thiomethyl group and one in the ortho-position with respect to it are introduced; by acting on 11 and on 35 the substitution involves the thiomethyl carbon atom and that in the ortho-position with respect to the alkoxy group.In the case of the homologeous isopropylthio (23) the substitution involves the two aryl carbon atoms in the ortho-position to both functions.In the case of the p-disubstituted isomers (49, 59) analogous behaviour to ortho isomers in one-step metalation reaction is observed, while the two hydrogen atoms in the ortho-positions to the methoxy group are substituted when two successive monometalations are employed.The metalation of 40 results low selective.The behaviour of 79 and 93 is analogous to 1, while 72, 88 and 96 undergo only one-step monometalation reactions.
- Cabiddu, Salvatore,Fattuoni, Claudia,Floris, Costantino,Gelli, Gioanna,Melis, Stefana,Sotgiu, Francesca
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p. 861 - 884
(2007/10/02)
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- Phenol alkylation and anisole rearrangement on AlPO4, TiO2, and AlPO4-TiO2 catalysts
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Using the microcatalytic pulse technique, the alkylation of phenol with methanol and the conversion of anisole in the presence of methanol were studied at temperatures ranging from 520 to 670 K over TiO2, AlPO4 and AlPO4-TiO2 (with different weight ratios
- Campelo, Juan-Manuel,Garcia, Angel,Luna, Diego,Marinas, Jose-Maria,Moreno, Maria-Sierra
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p. 283 - 292
(2007/10/02)
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- Substituent and Ring Size Dependence of the 4J(Me-C-C-H) Coupling Constant
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The magnitude of the 4J proton-proton coupling constant across the fragment CH3-C-C-H (a probe of the bond order between the central sp2-sp2 hybridized carbon atoms) has been found to be essentially independent of substitution on a toluene fragment and the size of the ring containing the ortho-allylic fragment.The coupling constant is sensitive to direct substitution on the ortho-allilyc fragment, especially where the substituent is placed α to methyl group.KEY WORDS - 4J proton-proton coupling constant ortho-benzylic coupling constant ring size dependence substituent dependence
- Collins, M. J.,Hatton, P. M.,Sternbell, S.,Tansey, C. W.
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p. 824 - 828
(2007/10/02)
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- Preparation and Reactions of Dianions from the Cresols
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With n-BuLi/KO-t-Bu, protons are removed from the hydroxyl and methyl groups of cresols 5 to give dianions 6 in yields of 85percent (ortho), 95percent (meta), and 42percent (para).These dianions react with alkyl halides, Me3SiCl, Bu3SnCl, CO2, and oxidizing agents at carbon only and with dialkyl sulfates at both carbon and oxygen.Thus phenol derivatives bearing primary alkyl groups can be prepared from the corresponding methylphenols via dianions 6.
- Bates, Robert B.,Siahaan, Teruna J.
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p. 1432 - 1434
(2007/10/02)
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- Reactions of the 1-hydroxy-1,4-dimethylcyclohexadienyl cation, an intermediate in the solvolysis of 1,4-dimethyl-4-nitrocyclohexa-2,5-dien-1-ol
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Solvolysis of 1,4-dimethyl-4-nitrocyclohexa-2,5-dien-1-ol in mixed aqueous organic solvents gives the diastereomers of 1,4-dimethylcyclohexa-2,5-dien-1,4-diol, 1,4-dimethylcyclohexa-3,5-diene-1,2-diol, 2-nitro-p-xylene, 2,4-dimethylphenol (all derived from the title cation, itself formed by ionization of the nitro group as nitrite), and 2,5-dimethylphenol.In aqueous methanol the diastereomers of 4-methoxy-1,4-dimethylcyclohexa-2,5-dienol are also obtained.Significant yields of 2,5-dimethylphenol are only obtained on the acid-catalyzed further reaction of the dienediol (or the methoxydienol) and involve the intermediate formation of 1,4-dimethylcyclohexa-3,5-diene-1,2-diol.In the absence of added base the acid released in the solvolysis catalyses this reaction and leads to the aromatization of the dienes.
- Fischer, Alfred,Henderson, George N.,Smyth, Trevor A.
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p. 1093 - 1101
(2007/10/02)
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- NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS. 46.1) TRIMETHYLSILYLDIAZOMETHANE: A CONVENIENT REAGENT FOR THE O-METHYLATION OF PHENOLS AND ENOLS
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Trimethylsilyldiazomethane reacts smoothly with phenols and enols in methanolic acetonitrile solution in the presence of N,N-diisopropylethylamine to give methyl ethers. KEYWORDS --- trimethylsilyldiazomethane; phenol; enol; O-methylation; methyl ether
- Aoyama, Toyohiko,Terasawa, Satomi,Sudo, Kimio,Shioiri, Takayuki
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p. 3759 - 3760
(2007/10/02)
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- Dienone-Phenol Rearrangements of Bicyclic Cyclohexa-2,5-dienones; Confirmation of a Multistage Mechanism
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Two mechanisms are well established for the dienone-phenol rearrangements of bicyclic cyclohexadienones of the 4a-alkyl-5,6,7,8-tetrahydronaphthalen-2(4aH)-one type, of which the 4a-methyl compound (1) and the steroidal 1,4-dien-3-ones are examples.They involve, for (1), either a direct alkyl shift from C-4a to C-4 and deprotonation to give a 4-alkyl-5,6,7,8-tetrahydro-2-naphthol or a shift of the 4a,5-bond from C-4a to C-8a with formation of a spiran intermediate and further ring migration from C-8a to C-1 to form a 4-alkyl-5,6,7,8-tetrahydro-1-naphthol.A further mechanism, for which there was little strong evidence, involves an alkyl shift from one angular position, C-4a, to the other, C-8a, followed by further ring migrations via a spiran intermediate to give an additional route to the 4-alkyltetrahydro-2-naphthol product.The products of rearrangement of 3,4a- and 1,4a-dimethyl-5,6,7,8-tetrahydronaphthalen-2(4aH)-ones in aqueous sulphuric acid, and in acetic anhydride with sulphuric acid catalysis, have been studied critically.The use of quantitative 13C n.m.r. spectroscopy confirms the identity and ratios of products deduced using 1H n.m.r. spectroscopy and other techniques.The results show that the third, suspect, mechanism does indeed operate, and that it contributes significantly to the formation of 4-alkyltetrahydro-2-naphthol products from both dienones.
- Waring, Anthony J.,Zaidi, Javid Hussain,Pilkington, James W.
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p. 1454 - 1459
(2007/10/02)
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