- Milled Dry Ice as a C1 Source for the Carboxylation of Aryl Halides
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The use of carbon dioxide as a C1 chemical feedstock remains an active field of research. Here we showcase the use of milled dry ice as a method to promote the availability of CO 2in a reaction solution, permitting practical synthesis of arylcarboxylic acids. Notably, the use of milled dry ice produces marked increases in yields relative to those obtained with gaseous CO 2, as previously reported in the literature.
- O'Brien, Connor J.,Nicewicz, David A.
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supporting information
p. 814 - 816
(2021/03/01)
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- Method for synthesizing 3 - n -butyl - l (3H)-isobenzofuranone (by machine translation)
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The invention discloses a method for synthesizing 3 - n -butyl - l (3H)-isobenzofuranone, firstly mixing Grignard reagent with Lewis acid, adjusting pH to acidity by an acid reagent, extracting with an organic solvent, concentrating and removing an organic solvent to obtain 3 - n -butyl - l (3H)-isobenzofuranone. (by machine translation)
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Paragraph 0046-0049
(2020/07/24)
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- COMPOUNDS
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A compound of formula (I), or a pharmaceutically acceptable salt thereof.
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Page/Page column 84
(2020/01/24)
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- MODULATORS OF HEMOGLOBIN
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The present disclosure relates generally to compounds and pharmaceutical compositions suitable as modulators of hemoglobin, and methods for their use in treating disorders mediated by hemoglobin.
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Paragraph 0235; 0342-0343; 0442-0443
(2020/06/08)
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- Polypyridyl iridium(III) based catalysts for highly chemoselective hydrogenation of aldehydes
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Iridium-catalyzed transfer hydrogenation (TH) of carbonyl compounds using HCOOR (R = H, Na, NH4) as a hydrogen source is a pivotal process as it provides the clean process and is easy to execute. However, the existing highly efficient iridium catalysts work at a narrow pH; thus, does not apply to a wide variety of substrates. Therefore, the development of a new catalyst which works at a broad pH range is essential as it can gain a broader scope of utilization. Here we report highly efficient polypyridyl iridium(III) catalysts, [Ir(tpy)(L)Cl](PF6)2 {where tpy = 2,2′:6′,2′'-Terpyridine, L = phen (1,10-Phenanthroline), Me2phen (4,7-Dimethyl-1,10-phenanthroline), Me4phen (3,4,7,8-Tetramethyl-1,10-phenanthroline), Me2bpy (4,4′-Dimethyl-2–2′-dipyridyl)} for the chemoselective reduction of aldehydes to alcohols in aqueous ethanol and sodium formate as the hydride source. The reaction can be carried out efficiently in broad pH ranges, from pH 6 to 11. These catalysts are air stable, easy to prepare using commercially available starting materials, and are highly applicable for a wide range of substrates, such as electron-rich or deficient (hetero)arenes, halogens, phenols, alkoxy, ketones, esters, carboxylic acids, cyano, and nitro groups. Particularly, acid and hydroxy groups containing aldehydes were reduced successfully in basic and acidic reaction conditions, demonstrating the efficiency of the catalyst in a broad pH range with high conversion rates under microwave irradiation.
- Pandrala, Mallesh,Resendez, Angel,Malhotra, Sanjay V.
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p. 283 - 288
(2019/09/30)
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- A chloroacetate based ratiometric fluorescent probe for cysteine detection in biosystems
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The specific detection of cysteine (Cys) over homocysteine (Hcy), glutathione (GSH) and other amino acids is of great significance for studying its biological functions as well as for the diagnosis of related diseases. Chloroacetyl group was often used as a reaction site for cysteine fluorescent probes for its sensitivity and selectivity. However, high background fluorescence and low stability are common problems encountered by such probes. Here, four chloroacetyl group based fluorescent probes (C1, C2, C3, and H4) was synthesized for a comparative study. We found that the inefficient quenching ability of chloroacetyl group turned into an advantage when connected with a ratiometric fluorophore. With the modification of chloroacetyl group, probe H4 displayed excellent ratiometric property and great selectivity for Cys, the stability was also improved. Additionally, the probe was successfully applied for quantitative detection of Cys in fetal bovine serum and real-time imaging in living HeLa cells with low toxicity.
- Liu, Zhengkun,Wang, Qianqian,Wang, Hao,Su, Wenting,Dong, Shouliang
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supporting information
(2019/10/08)
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- Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source
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A water-soluble highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water. The reduction uses formic acid as the traceless reducing agent and water as a solvent. It can be carried out in air without the need for inert atmosphere protection. The products can be purified by simple extraction without any column chromatography. The catalyst loading can be as low as 0.005 mol% and the turn-over frequency (TOF) is as high as 73 800 mol mol-1 h-1. A wide variety of functional groups, such as electron-rich or deficient (hetero)arenes and alkenes, alkyloxy groups, halogens, phenols, ketones, esters, carboxylic acids, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity.
- Yang, Zhanhui,Zhu, Zhongpeng,Luo, Renshi,Qiu, Xiang,Liu, Ji-Tian,Yang, Jing-Kui,Tang, Weiping
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supporting information
p. 3296 - 3301
(2017/07/28)
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- A to phthaldialdehyde as the raw material to synthesize method of doxepin hydrochloride (by machine translation)
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This invention discloses in a to phthaldialdehyde as the raw material to synthesize method of doxepin hydrochloride. The method comprises in a wide range of sources phthaldialdehyde as the starting material, reaction by sequentially connie Zha Luo, intramolecular esterification, substituted, cyclized, nucleophilic addition, elimination reactions, nucleophilic substitution, pro-nuclear substituted, and in the reaction, to obtain liu Danhuang pyridine. In section 8 step in the nucleophilic substitution reaction steps, yu Mi using organic lithium compound in the solvent, so that the organic compound forming ammonium lithium salt with dimethylamine , Then this ammonium lithium salt for carrying out the alkylation reaction with halo, improve the yield of the addition, the ultimate so as to guarantee the yield and purity of doxepin hydrochloride. Phthaldialdehyde cheap, so as to reduce the production cost. (by machine translation)
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Paragraph 0083
(2016/10/10)
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- Electrophilicity and nucleophilicity of commonly used aldehydes
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The present approach for determining the electrophilicity (E) and nucleophilicity (N) of aldehydes includes a kinetic study of KMNO4 oxidation and NaBH4 reduction of aldehydes. A transition state analysis of the KMNO4 promoted aldehyde oxidation reaction has been performed, which shows a very good correlation with experimental results. The validity of the experimental method has been tested using the experimental activation parameters of the two reactions. The utility of the present approach is further demonstrated by the theoretical versus experimental relationship, which provides easy access to E and N values for various aldehydes and offers an at-a-glance assessment of the chemical reactivity of aldehydes in various reactions. the Partner Organisations 2014.
- Pratihar, Sanjay
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p. 5781 - 5788
(2014/07/22)
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- Catalytic oxidation of aromatic hydrocarbons by mono-oxido- alkoxidovanadium(V) complexes of ONNO donor ethylenediaminebis(phenolate) ligands
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Two oxidovanadium(V) complexes, [VVO(L1)(OMe)] (1) and [VVO(L2)(OMe)] (2), with ONNO donor ethylenediamine-bis(phenolate) ligands (H2L1 and H2L2) have been readily synthesized by the reaction between the ligand precursors and VOSO4·5H2O in MeOH, and characterized by physico-chemical techniques and single crystal X-ray diffraction studies. Both complexes 1 and 2 are hexa-coordinated with a pseudo-octahedral geometry in an N2O4 coordination environment and are found to catalyze the oxidation of toluene to benzoic acid and isomers of xylene to the corresponding hydroxy acids, with turnover numbers (TON) over 200, except for o-xylene. On changing the ligand fragments and coordination geometry around the metal centre there is an improvement in the catalytic efficiency, selectivity and also TON of the reaction as compared with the previously reported systems. The reactions were monitored using 51V NMR spectroscopy. Based on mass spectra analysis and 51V NMR studies, the mechanism of the catalytic process has been proposed, employing the formation of oxido-hydroperoxido/hydroxido-peroxido [V(ONNO)(O)(OOH)] ? [V(OH)(ONNO)(O2)] intermediates.
- Debnath, Mainak,Dutta, Arpan,Biswas, Surajit,Das, Kalyan Kumar,Lee, Hon Man,Vícha, Jan,Marek, Radek,Marek, Jaromir,Ali, Mahammad
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p. 189 - 198
(2013/10/22)
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- An efficient synthesis of symmetric and unsymmetric bis-(β- aminoamides) via Ugi multicomponent reaction
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A library of symmetrical and unsymmetrical bis-(β-aminoamides) has been prepared starting from symmetrical secondary diamines by using a double Ugi four-component reaction. A sacrifical Mumm rearrangement, thanks to the use of 2-hydroxymethyl benzoic acid, is necessary to suppress the competing split-Ugi reaction, increasing the yield and simplifying the purification step. The scope, the reaction conditions, and the role of water in trapping the nitrilium intermediate are also discussed.
- La Spisa, Fabio,Feo, Alberto,Mossetti, Riccardo,Tron, Gian Cesare
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supporting information
p. 6044 - 6047
(2013/02/23)
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- Selective aerobic oxidation of para-xylene in sub- and supercritical water. Part 1. Comparison with ortho-xylene and the role of the catalyst
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The selective, continuous, aerobic oxidations of para-xylene (pX) and ortho-xylene (oX) were performed in an identical fashion in supercritical water. The xylenes were oxidized without a catalyst and with hydrobromic acid, cobalt(ii) and manganese(ii) bromide catalysts. The conversions and yields to phthalic acid (OA) from oX were always significantly higher than those for terephthalic acid (TA) from pX. The formation of CO2 was significantly higher for pX than oX despite the higher conversions to oX. These results are unexpected because the literature teaches that thermal and catalytic decarboxylation is much higher for OA than TA. The superior yields from oX are consistent with a lower steady-state concentration of hydroxyl radicals, OH due to the internal, concerted attack of the peroxides with the oX methyl group. This mechanism forms the phthalide directly from o-tolualdehyde (oTOL) which is consistent with the observation that ortho-toluic acid (OTA) is much lower in oX than para-toluic acid, PTA, in pX oxidation. This mechanism also lowers the steady-state concentration of aromatic acids consistent with the observed lower benzoic acid and CO2 yields. Overall, the results suggest that the metal catalysts can play more than one role, thereby opening up the opportunity for discovering new catalytic synergies which are explored in our next paper, Part 2 of this series.
- Perez, Eduardo,Fraga-Dubreuil, Joan,Garcia-Verdugo, Eduardo,Hamley, Paul A.,Thomas, W. Barry,Housley, Duncan,Partenheimer, Walt,Poliakoff, Martyn
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experimental part
p. 2389 - 2396
(2011/10/13)
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- Domino rhodium/palladium-catalyzed dehydrogenation reactions of alcohols to acids by hydrogen transfer to inactivated alkenes
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The combination of the d8 RhI diolefin amide [Rh(trop2N)(PPh3)] (trop2N=bis(5-H-dibenzo-[a, d]cyclohepten-5-yl)amide) and a palladium heterogeneous catalyst results in the formation of a superior catalyst system for the dehydrogenative coupling of alcohols. The overall process represents a mild and direct method for the synthesis of aromatic and heteroaromatic carboxylic acids for which inactivated olefins can be used as hydrogen acceptors. Allyl alcohols are also applicable to this coupling reaction and provide the corresponding saturated aliphatic carboxylic acids. This transformation has been found to be very efficient in the presence of silica-supported palladium nanoparticles. The dehydrogenation of benzyl alcohol by the rhodium amide, [Rh]N, follows the well established mechanism of metal-ligand bifunctional catalysis. The resulting amino hydride complex, [RhH]NH, transfers a H2 molecule to the Pd nanoparticles, which, in turn, deliver hydrogen to the inactivated alkene. Thus a domino catalytic reaction is developed which promotes the reaction R-CH 2-OH+NaOH+ 2 alkene→R-COONa+2 alkane.
- Trincado, Monica,Gruetzmacher, Hansjorg,Vizza, Francesco,Bianchini, Claudio
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supporting information; experimental part
p. 2751 - 2757
(2010/06/17)
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- CuCl catalyzed selective oxidation of primary alcohols to carboxylic acids with tert-butyl hydroperoxide at room temperature
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Direct oxidation of primary alcohols to the corresponding carboxylic acids is performed highly efficiently at room temperature with anhydrous tert-butyl hydroperoxide in the presence of a catalytic amount of easily available CuCl under ligand free conditions in acetonitrile. Benzylic alcohols are more reactive than aliphatic alcohols, and these benzylic alcohols are selectively oxidized to the corresponding acids in the presence of aliphatic alcohols such as 1-octanol and 1-decanol.
- Mannam, Sreedevi,Sekar
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p. 2457 - 2460
(2008/09/20)
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- Electrochemical carboxylation of 2-iodoaromatic compounds
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The electrochemical reduction of a series of 2-iodoaromatic substituted compounds in acetonitrile under an atmospheric pressure of carbon dioxide leads to ortho-substitued aromatic carboxylic acid. The maximum yield of acid obtained by electrolysis performed in a diaphragm-less cell at low temperature (5°C) with a sacrificial magnesium anode and by the use of a low current density was slightly higher than 70%.
- Korbi, B. Haouas,Adhoum,Boujlel
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p. 2557 - 2564
(2007/10/03)
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- Revised structure for spatozoate, a metabolite of Spatoglossum variabile
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Structure of spatozoate, n-butyl 2-benzoyloxymethylbenzoate 1, a metabolite of Spatoglossum variabile has been revised into benzyl n-butyl phthalate 2 by synthesis. NMR spectral data of synthetic 2 agrees well with those reported for the natural spatozoate.
- Cheng, Kur-Ta,Rajasekhar, Dodda,Huang, Sheng-Tung,Hsu, Feng-Lin,Subbaraju, Gottumukkala V.
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p. 1190 - 1192
(2007/10/03)
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- WATER-SOLUBLE TRIAZOLE FUNGICIDE
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A triazole compound of the general formula (I) or a pharmacologically acceptable salt thereof: [wherein,X represents a group of formula X-OH which has antifungal activity,L represents a -(adjacently substituted C6-C10 aryl)-CH2-group and the like, andR represents a -P(=O) (OH)2 group and the like.
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Page/Page column 139-140; 143
(2010/02/07)
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- A New Strategy for the Preparation of Terephthalic Acid by the Aerobic Oxidation of p-Xylene Using N-Hydroxyphthalimide as a Catalyst
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A new methodology for the production of terephthalic acid (5) by the aerobic oxidation of p-xylene (1) using a combined catalytic system of N-hydroxyphthalimide (NHPI)/Co(OAc)2/Mn(OAc)2 was developed. The oxidation of 1 under a dioxygen atmosphere in the presence of a catalytic amount of NHPI/Co(OAc)2/Mn(OAc)2 at 100°C for 14 h afforded terephthalic acid in 82percent yield. Removal of Mn(OAc)2 from the catalytic system resulted in considerable reduction in the yield of 3. When the oxidation of 1 was carried out under a pressure of air (30 atm) at 150°C, the reaction was completed within 3 h to give 3 in 84percent yield. The oxidation of p-toluic acid (2), which can be prepared by the oxidation of 1 using the NHPI/Co(OAc)2 system at room temperature, by the NHPI/Co(OAc)2/Mn(OAc)2 system under pressure of air (30 aim) at 150°C gave 3 in 95percent yield. N-Acetoxyphthalimide (NAPI) was found to require a lower catalyst loading than NHPI, but oxidation with NAPI was slower. Thus, the oxidation of 1 catalyzed by NAPI (5 mol percent)/Co(OAc)2 (0.5 mol percent)/Mn(OAc)2 (0.5 mol percent) under a dioxygen atmosphere (1 atm) in acetic acid at 100°C gave 3 in 80percent yield.
- Tashiro, Yasutaka,Iwahama, Takahiro,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 220 - 225
(2007/10/03)
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- Remarkable control of radical cyclization processes of cyclic enyne: Total syntheses of (±)-methyl gummiferolate, (±)-methyl 7β-hydroxykaurenoate, and (±)-methyl 7-oxokaurenoate and formal synthesis of (±)-gibberellin A12 from a common synthetic precursor
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Total syntheses of (±)-methyl gummiferolate (13b), (±)-methyl 7β-hydroxykaurenoate (14b), and (±)-methyl 7-oxokaurenoate (14d) and a formal synthesis of (±)-gibberellin A12 (15) have been accomplished through the common synthetic precursor, (3aR*,7aR*)-3,3-dimethyl-7a-(2-propynyl)-3a,4,7,7a- tetrahydroisobenzofuranone (16). The homoallyl - homoallyl radical rearrangement reaction of the monocyclic enyne 25, derived from 16 in two steps, afforded the bicyclo[2,2,2]octane compound 26, which was converted to (±)-methyl gummiferolate (13b). In contrast, the radical cyclization of the bicyclic enyne 16 gave the tricyclic lactone 19, leading to (±)-methyl 7β-hydroxykaurenoate (14b) and (±)-methyl 7-oxokaurenoate (14d). Transformation of 14d into lactone 20 was carried out in a single step under bromination conditions. This constitutes a formal total synthesis of gibberellin A12 (15).
- Toyota,Yokota,Ihara
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p. 1856 - 1861
(2007/10/03)
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- Oligonucleotide synthesis by the use of a 2-(levulinyloxymethyl)-5-nitrobenzoyl group as the novel base-labile protecting group for the 5'-hydroxyl groups of ribonucleoside and 2'-deoxyribonucleoside 3'-phosphoramidites
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A novel 2-(levulinyloxymethyl)-5-nitrobenzoyl (LMNBz) protecting group for the 5' position of nucleoside 3'-phosphoramidites was successfully applied to the solid-phase synthesis of both an oligodeoxyribonucleotide (TpTpT and TpTpTpT) and an octaribonucleotide in combination with a 2'-O-Thp protecting group (UpCpApGpUpUpGpG). The LMNBz group was simply unmasked due to its base-labile property by a two-step procedure, i.e., treatments with 0.5 M hydrazine hydrate in 1:4 acetic acid - pyridine, and then with 0.5 M imidazole in acetonitrile.
- Kamaike, Kazuo,Takahashi, Hiroaki,Kakinuma, Takashi,Morohoshi, Kimio,Ishido, Yoshiharu
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p. 6857 - 6860
(2007/10/03)
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- IMPROVED PROCEDURE FOR THE REDUCTION OF ESTERS TO ALCOHOLS BY SODIUM BOROHYDRIDE
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An improved procedure for the employment of NaBH4 in the reduction of ester function is described.
- Bianco, A.,Passacantilli, P.,Righi, G.
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p. 1765 - 1772
(2007/10/02)
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- Generation and Thermal Reactions of 2-Methyl-4-oxo-2-selenoniochroman-3-ide
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The thermal reaction of 2-methyl-4-oxo-2-selenoniochroman-3-ide (4) in aprotic solvents afforded (E)-bisbenzoyl>ethylene (5) and trans-1,2,3-trisbenzoyl>cyclopropane (6) via a carbene intermediate.Ethanol reacted thermally with 4 to open the chroman ring, giving ethyl 2-benzoate (9a) and ethyl 2-(ethoxymethyl)benzoate (10a), whereas reaction with methanol yielded only methyl 2-benzoate (9b).Hydrolysis of ylide 4 eliminated dimethyl selenide, giving phthalide and 2-(hydroxymethyl)benzoic acid.
- Hori, Mikio,Kataoka, Tadashi,Shimizu, Hiroshi,Tsutsumi, Kazuhiro
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p. 1397 - 1400
(2007/10/02)
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