- A novel method for protection and deprotection of the carbonyl groups in 1,2-indanedione by conversion to dioxa-dithiapropellanes
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1,2-Indanedione reacts with two equivalents of 2-mercaptoethanol to produce, instead of the expected 1,2-bis(1,3-oxathiolane), a dioxa-dithia[4.4.3] propellane. Other 1,2-indanediones produce analogous compounds. The protecting groups are removed at room temperature with NBS in aqueous acetone, to produce the original diketone.
- Almog, Joseph,Zehavy, Yirmi,Cohen, Shmuel
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- Investigations of the reaction mechanisms of 1,2-indanediones with amino acids
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The reaction mechanisms of amino acids with a new class of fluorogenic reagents were investigated. The structures of colored and fluorescent species formed in these reactions were partially confirmed by experimental evidence. Reaction intermediates, C-N-C 1,3-dipoles derived from imines, were trapped with dipolarophiles in 3 + 2 cycloadditions to form spiropyrrolidines.
- Petrovskaia,Taylor,Hauze,Carroll,Joullie
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- Tris(pentafluorophenyl)borane-Catalyzed Oxygen Insertion Reaction of α-Diazoesters (α-Diazoamides) with Dimethyl Sulfoxide
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A tris(pentafluorophenyl)borane-catalyzed oxidation reaction of α-diazoesters (α-diazo amides) with dimethyl sulfoxide has been developed. The reaction proceeds under metal free conditions to afford a series α-ketoesters and α-ketoamides. The synthetic utility of this protocol is demonstrated through synthetic transformations and scaled-up synthesis. (Figure presented.).
- Wu, Xiao-Yang,Gao, Wen-Xia,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
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supporting information
p. 750 - 754
(2022/01/19)
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- Homogeneous catalytic oxidation of alkenes employing mononuclear vanadium complex with hydrogen peroxide
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Abstract: Homogeneous liquid-phase oxidation of alkenes (allylbenzene, cis-cyclooctene, 4-chlorostyrene, styrene, 2-norbornene, 1-methyl cyclohexene, indene, lemonine, and 1-hexene) were catalyzed by using vanadium complex [VO(hyap)(acac)2] in existence of H2O2. The complex [VO(hyap)(acac)2] was formed as a crystal by the reaction of [VO(acac)2] and 2-hydroxyacetophenone (hyap) in the presence of methanol by refluxing the reaction mixture. Various analytical and spectroscopic techniques, namely FTIR, ESI–MS, UV–Vis, single-crystal XRD, and EPR, were used to analyze and optimize the structure of the complexes. Graphic abstract: [Figure not available: see fulltext.].
- Maurya, Abhishek
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p. 3261 - 3269
(2020/07/14)
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- A Bifunctional Iron Nanocomposite Catalyst for Efficient Oxidation of Alkenes to Ketones and 1,2-Diketones
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We herein report the fabrication of a bifunctional iron nanocomposite catalyst, in which two catalytically active sites of Fe-Nx and Fe phosphate, as oxidation and Lewis acid sites, were simultaneously integrated into a hierarchical N,P-dual doped porous carbon. As a bifunctional catalyst, it exhibited high efficiency for direct oxidative cleavage of alkenes into ketones or their oxidation into 1,2-diketones with a broad substrate scope and high functional group tolerance using TBHP as the oxidant in water under mild reaction conditions. Furthermore, it could be easily recovered for successive recycling without appreciable loss of activity. Mechanistic studies disclose that the direct oxidation of alkenes proceeds via the formation of an epoxide as intermediate followed by either acid-catalyzed Meinwald rearrangement to give ketones with one carbon shorter or nucleophilic ring-opening to generate 1,2-diketones in a cascade manner. This study not only opens up a fancy pathway in the rational design of Fe-N-C catalysts but also offers a simple and efficient method for accessing industrially important ketones and 1,2-diketones from alkenes in a cost-effective and environmentally benign fashion.
- Ma, Zhiming,Ren, Peng,Song, Tao,Xiao, Jianliang,Yang, Yong,Yuan, Youzhu
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p. 4617 - 4629
(2020/05/19)
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- Doped graphene as a metal-free carbocatalyst for the selective aerobic oxidation of benzylic hydrocarbons, cyclooctane and styrene
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Nitrogen (N)-, boron (B)-, and boron,nitrogen (B,N)-doped graphene (G) act as carbocatalysts, promoting the aerobic oxidation of the benzylic positions of aromatic hydrocarbons and cyclooctane to the corresponding alcohol/ketone mixture with more than 90 % selectivity. The most active material was the co-doped (B,N)G, which, in the absence of solvent and with a substrate/(B,N)G ratio of 200, achieved 50 % tetralin conversion in 24 h with a alcohol/ketone selectivity of 80 %. An FT-Raman spectroscopic study of a sample of (B,N)G heated at 100 °C in the presence of oxygen revealed new bands that disappeared upon evacuation and that have been attributed to hydroperoxide-like species formed on the G sheet based on the isotopic shift of the peak from 819 to 779 cm-1 when 18O2 was used as the oxidizing reagent. Furthermore, (B)G and (N)G exhibited high catalytic activity in the aerobic oxidation of styrene to benzaldehyde (BA) in 4 h. However, the product distribution changed over time and after 10 h a significant percentage of styrene oxide (SO) was observed under the same conditions. The use of doped G as catalyst appears to offer broad scope for the aerobic oxidation of benzylic compounds and styrene, for which low catalyst loading, mild reaction temperatures, and no additional solvents are required. Oxidation at graphene: Boron- and nitrogen-doped graphenes are excellent catalysts for promoting the oxidation of benzylic hydrocarbons, cyclooctane, and styrene with molecular oxygen at 0.5 wt % under atmospheric pressure and solvent-free conditions (see figure). Copyright
- Dhakshinamoorthy, Amarajothi,Primo, Ana,Concepcion, Patricia,Alvaro, Mercedes,Garcia, Hermenegildo
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p. 7547 - 7554
(2013/07/11)
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- Emulation of racemase activity by employing a pair of stereocomplementary biocatalysts
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Racemization is the key step to turn a kinetic resolution process into dynamic resolution. A general strategy for racemization under mild reaction conditions by employing stereoselective biocatalysts is presented, in which racemization is achieved by employing a pair of stereocomplementary biocatalysts that reversibly interconvert an sp3 to a sp2 center. The formal interconversion of the enantiomers proceeds via a prochiral sp 2 intermediate the formation of which is catalyzed either by two stereocomplementary enzymes or by a single enzyme with low stereoselectivity. By choosing appropriate reaction conditions, the amount of the prochiral intermediate is kept to a minimum. This general strategy, which is applicable to redox enzymes (e.g., by acting on R2CHOH and R2CHNHR groups) and lyase-catalyzed addition-elimination reactions, was proven for the racemization of secondary alcohols by employing alcohol dehydrogenases. Thus, enantiopure chiral alcohols were used as model substrates and were racemized either with highly stereoselective biocatalysts or by using (rarely found) non-selective enzymes.
- Gruber, Christian C.,Nestl, Bettina M.,Gross, Johannes,Hildebrandt, Petra,Bornscheuer, Uwe T.,Faber, Kurt,Kroutil, Wolfgang
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p. 8271 - 8276
(2008/04/01)
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- Arylindenopyridines and arylindenopyrimidines and related therapeutic and prophylactic methods
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This invention provides novel arylindenopyridines and arylindenopyrimidines of the formula: wherein R1, R2, R3, R4, and X are as defined above, and pharmaceutical compositions comprising same, useful for treating disorders ameliorated by antagonizing adenosine A2a receptors. This invention also provides therapeutic and prophylactic methods using the instant compounds and pharmaceutical compositions.
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- New synthetic methods: Part I - Regioselective 1, 2-transposition of carbonyl group in carbocyclic and heterocyclic ketones
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A convenient and simple synthetic method for 1, 2- transposition of keto group in pyrazol-5-ones, indan-1,3-dione and benzofuran-3-one is described.
- Chande, Madhukar S.,Amle, Anand P.
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p. 2625 - 2627
(2007/10/03)
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- Oxoammonium resins as metal-free, highly reactive, versatile polymeric oxidation reagents
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Polymer-supported oxidation of alcohols was conducted very efficiently by employing oxoammonium salts, the reactive intermediates in TEMPO oxidations (TEMPO = 2,2,6,6-tetramethylpiperidinoxyl). These highly reactive salts (see scheme; X = Br, C1) could be prepared and isolated on the polymeric support, and were used for the conversion of single compounds as well as of complex mixtures of alcohols.
- Weik, Steffen,Nicholson, Graeme,Jung, Gnther,Rademann, Jrg
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p. 1436 - 1439
(2007/10/03)
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- Process for the preparation cis-(1S,2R)-indanediol by direduction of 1,2-indanedione using trichosporon cutaneum
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A process for preparing cis-(1S,2R)-indanediol is disclosed. The process comprises (A) fermenting a culture medium containing a yeast strain selected from the group consisting of Trichosporon cutaneum MY 1506 (ATCC 74440) and mutants thereof and 1,2-indanedione to form cis-(1S,2R)-indanediol; and (B) recovering cis-(1S,2R)-indanediol from the culture medium. A process for preparing (1S)-amino-(2R)-indanol from the recovered cis-(1S,2R)-indanediol via the Ritter reaction is also disclosed.
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- Selective alkene oxidation with H2O2 and a heterogenized Mn catalyst: Epoxidation and a new entry to vicinal cis-diols
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Covalent anchoring of 1,4-dimethyl-1,4,7-triazacyclononane on silica gel is the first step in the preparation of a heterogenized Mn catalyst. When H2O2 is used as the oxidant, this material can catalyze the vicinal cis- dihydroxylation of disubstituted olefins, as shown schematically here. Both enantiomers of the product are obtained.
- De Vos, Dirk E.,De Wildeman, Stefaan,Sels, Bert F.,Grobet, Piet J.,Jacobs, Pierre A.
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p. 980 - 983
(2007/10/03)
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- Oxidation by DMSO. II. An efficient synthesis of α,β-diketones from α,β-dibromides
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α,β-Dibromides refluxed in DMSO are oxidised into α,β-diketones. The reaction takes place rapidly under microwave irradiation.
- Villemin,Hammadi
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p. 3145 - 3148
(2007/10/02)
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- Photolysis of cyclic enol esters in the presence or absence of a single electron transfer photosensitizer
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The photochemistry of enol esters 1 is dominated by electrocyclic ring opening (1b → 3+4), 1,3-acyl migration (1c,d → 6c,d) and [2 + 2] dimerization (1d → 11). Photosensitization with triphenylpyrylium tetrafluoroborate (TPT) enhances formation of oxidation products (1b → 5,1c,d → 9c,d + 10c,d), presumably through the intermediacy of radical cations 1b-d+.
- Climent,Garcia,Iborra,Miranda,Primo
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p. 9289 - 9296
(2007/10/02)
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- Anti-allergic pharmaceutical compositions
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2-Nitroindane-1,3-dione derivatives are useful in the prophylaxis and treatment of asthma, hay fever and also in the treatment of rhinitis.
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