- Photocatalytic Stoichiometric Oxidant-Free Synthesis of Linear Unsaturated Ketones from 1,2-Disubstituted Cyclopropanols
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A one-step catalytic oxidant-free synthesis of unsaturated ketones from 1,2-disubstituted cyclopropanols is reported. Previously for this transformation, only two- and three-step protocols have been developed. The reaction proceeds under irradiation with visible light in the presence of catalytic amounts of both an acridinium photocatalyst and a cobaloxime complex. 2-Aryl-substituted cyclopropanols react giving α,β-unsaturated ketones, while dehydrogenative ring opening of 2-alkyl-substituted substrates affords mixtures of α,β- and β,γ-enones. The reaction starts with one-electron oxidation of a cyclopropanol to cyclopropyloxy radical, presumably, by the photoexcited acridinium catalyst. We also found that Co(dmgBF 2) 2(MeCN) 2complex under an air atmosphere and irradiation with blue LEDs or upon heating can serve as a hydroxycyclopropane oxidant.
- Laktsevich-Iskryk, Marharyta V.,Krech, Anastasiya V.,Zhabinskii, Vladimir N.,Khripach, Vladimir A.,Hurski, Alaksiej L.
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supporting information
p. 1077 - 1086
(2020/12/14)
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- Borane-Catalyzed Direct Asymmetric Vinylogous Mannich Reactions of Acyclic α,β-Unsaturated Ketones
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Herein, we report that, by using chiral bicyclic bisborane catalysts, we have achieved the first highly regio-, diastereo-, and enantioselective direct asymmetric vinylogous Mannich reactions of acyclic α,β-unsaturated ketones. The strong Lewis acidity and steric bulk of the bisborane catalysts were essential for the observed high yields and selectivities.
- Tian, Jun-Jie,Liu, Ning,Liu, Qi-Fei,Sun, Wei,Wang, Xiao-Chen
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supporting information
p. 3054 - 3059
(2021/03/01)
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- 1,2-Carbopentafluorophenylation of Alkynes: The Metallomimetic Pull-Push Reactivity of Tris(pentafluorophenyl)borane
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We report the novel single-step 1,2-dicarbofunctionalization of an arylacetylene with an allylsilane and tris(pentafluorophenyl)borane [B(C6F5)3] involving C?C bond formation with C?H bond scission at the β-position to the silicon atom of an allylsilane and B→C migration of a C6F5 group. The 1,2-carbopentafluorophenylation occurs smoothly without the requirement for a catalyst or heating. Mechanistic studies suggest that the metallomimetic “pull-push” reactivity of B(C6F5)3 imparts consecutive electrophilic and nucleophilic characteristics to the benzylic carbon of the arylacetylene. Subsequent photochemical 6π-electrocyclization affords tetrafluoronaphthalenes, which are important in the pharmaceutical and materials sciences. Owing to the unique reactivity of B(C6F5)3, the 1,2-carbopentafluorophenylation using 2-substituted furan proceeded with ring opening, and the reaction using silyl enolates formed a C?C bond with C?O bond scission at the silyloxy-substituted carbon.
- Shibuya, Masatoshi,Matsuda, Miki,Yamamoto, Yoshihiko
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supporting information
p. 8822 - 8831
(2021/05/21)
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- Three-Component Coupling of Acyl Fluorides, Silyl Enol Ethers, and Alkynes by P(III)/P(V) Catalysis
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We report herein on the phosphine-catalyzed hydrovinylation reaction by three-component coupling of acyl fluorides, silyl enol ethers, and alkynoates. The key to the success of the reaction is the formal transmetalation between pentacoordinate P(V) species (i.e., fluorophosphorane) and a silyl enol ether, which allows for C-C bond formation between the polarity-mismatched sites. The bond formation that cannot be attained even by transition metal catalysis is accomplished by a P(III)/P(V) manifold.
- Fujimoto, Hayato,Kusano, Momoka,Kodama, Takuya,Tobisu, Mamoru
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supporting information
p. 18394 - 18399
(2021/11/22)
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- Electrochemical, Iodine-Mediated α-CH Amination of Ketones by Umpolung of Silyl Enol Ethers
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The electrochemical, oxidative Umpolung reaction of silyl enol ethers utilizing simple iodide salts for the synthesis of α-amino ketones is described. The products were isolated in excellent yields of up to 100percent, and various functionalized starting materials were accepted in an undivided electrochemical cell design. Moreover, a sensitivity assessment to ensure an improved reproducibility of the reaction and cyclic voltammetry experiments were performed to postulate a plausible reaction mechanism on their basis.
- Strehl, Julia,Hilt, Gerhard
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supporting information
p. 5968 - 5972
(2020/08/12)
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- C?O coupling of Malonyl Peroxides with Enol Ethers via [5+2] Cycloaddition: Non-Rubottom Oxidation
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Malonyl peroxides act both as oxidants and reagents for C?O coupling in reactions with methyl and silyl enol ethers. In the proposed conditions, the oxidative C?O coupling of malonyl peroxides with enol ethers selectively proceeds, bypassing the traditional Rubottom hydroxylation of enol ethers by peroxides. It was observed that the oxidative [5+2] cycloaddition of malonyl peroxides and enol ethers is the key stage of the discovered process. Oxidative C?O coupling of silyl enol ethers leads to the formation of α-acyloxyketones with a free carboxylic acid group. A specially developed preparative one-pot procedure transforms ketones via silyl enol ethers formation and the following coupling into α-acyloxyketones with yields 35–88%. The acid-catalyzed coupling with methyl enol ethers gives remarkable products while retaining the easily oxidizable enol fragment. Furthermore, these molecules contain a free carboxylic acid group, thus these nontrivial products contain two usually incompatible acid and enol ether groups. (Figure presented.).
- Vil', Vera A.,Gorlov, Evgenii S.,Bityukov, Oleg V.,Barsegyan, Yana A.,Romanova, Yulia E.,Merkulova, Valentina M.,Terent'ev, Alexander O.
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supporting information
p. 3173 - 3181
(2019/05/15)
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- Alkyl Ethers as Traceless Hydride Donors in Br?nsted Acid Catalyzed Intramolecular Hydrogen Atom Transfer
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A new protocol for the deoxygenation of alcohols and the hydrogenation of alkenes under Br?nsted acid catalysis has been developed. The method is based on the use of either a benzyl or isopropyl ether as a traceless hydrogen-atom donor, and involves an intramolecular hydride transfer as a key step, which is achieved in a regio- and stereoselective manner.
- Gandamana, Dhika Aditya,Wang, Bin,Tejo, Ciputra,Bolte, Benoit,Gagosz, Fabien,Chiba, Shunsuke
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supporting information
p. 6181 - 6185
(2018/05/03)
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- Enantioselective N-Heterocyclic Carbene Catalyzed Synthesis of Functionalized Indenes
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An enantioselective NHC (N-heterocyclic carbene) catalyzed synthesis of indenes from bifunctional α,β-unsaturated acyl fluorides and TMS enol ethers has been discovered. The reaction has broad generality (31 examples) and proceeds with high levels of enantioselectivity (most >92:8 er). Mechanistically the reaction likely occurs via a Michael/β-lactonization/decarboxylation sequence. Derivatization studies and limitations are discussed.
- Zhang, Changhe,Lupton, David W.
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supporting information
p. 4456 - 4459
(2017/09/11)
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- Tying a Molecular Overhand Knot of Single Handedness and Asymmetric Catalysis with the Corresponding Pseudo-D3-Symmetric Trefoil Knot
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We report the stereoselective synthesis of a left-handed trefoil knot from a tris(2,6-pyridinedicarboxamide) oligomer with six chiral centers using a lanthanide(III) ion template. The oligomer folds around the lanthanide ion to form an overhand knot complex of single handedness. Subsequent joining of the overhand knot end groups by ring-closing olefin metathesis affords a single enantiomer of the trefoil knot in 90% yield. The knot topology and handedness were confirmed by NMR spectroscopy, mass spectrometry, and X-ray crystallography. The pseudo-D3-symmetric knot was employed as an asymmetric catalyst in Mukaiyama aldol reactions, generating enantioselectivities of up to 83:17 er, which are significantly higher than those obtained with a comparable unknotted ligand complex.
- Gil-Ramírez, Guzmán,Hoekman, Steven,Kitching, Matthew O.,Leigh, David A.,Vitorica-Yrezabal, I?igo J.,Zhang, Gen
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p. 13159 - 13162
(2016/10/22)
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- Stereoselective Synthesis of Highly Substituted Tetrahydrofurans through Diverted Carbene O-H Insertion Reaction
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Copper- or rhodium-catalyzed reactions of diazocarbonyl compounds with β-hydroxyketones give highly substituted tetrahydrofurans with excellent diastereoselectivity. Under mild conditions, the single-step process starts as a carbene O-H insertion reaction, but is diverted by an intramolecular aldol reaction. Gone astray: Copper- or rhodium-catalyzed reactions of diazocarbonyl compounds with β-hydroxyketones give highly substituted tetrahydrofurans with excellent diastereoselectivity. The single-step reaction proceeds under mild conditions, starting as a carbene O-H insertion reaction, but then diverting to an intramolecular aldol reaction.
- Nicolle, Simon M.,Lewis, William,Hayes, Christopher J.,Moody, Christopher J.
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supporting information
p. 8485 - 8489
(2015/11/27)
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- Highly stereoselective oxazaborolidinium ion catalyzed synthesis of (Z)-silyl enol ethers from alkyl aryl ketones and trimethylsilyldiazomethane
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Highly stereoselective (Z)-silyl enol ethers were prepared from alkyl aryl ketones and trimethylsilyldiazomethane (TMSD) using an oxazaborolidinium ion catalyst. In addition, ring-expanded silyl enol ethers were successfully constructed from cyclic ketones. Their synthetic utilities were shown by sequential Mukaiyama aldol and [2 + 2]-cycloaddition reactions.
- Kang, Byung Chul,Shim, Su Yong,Ryu, Do Hyun
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p. 2077 - 2079
(2014/05/06)
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- Preparation of polymer incarcerated gold nanocluster catalysts (PI-Au) and their application to aerobic oxidation reactions of boronic acids, alcohols, and silyl enol ethers
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Heterogeneous gold nanocluster catalysts immobilized by the method known as polymer incarceration were prepared. Polystyrene-derived polymers with epoxide and alcohol moieties, which could be cross-linked under heating conditions, were employed as supports for their preparation. Cationic gold salts were reduced in a solution of NaBH4 and the polymers. Poor solvents for the polymers were added, and the polymers were precipitated and encapsulated gold nanoclusters with weak but multiple interactions between a gold nanocluster surface and the π electrons of benzene rings. The polymer capsules were heated under neat conditions to afford heterogeneous gold nanocluster catalysts; namely, polymer-incarcerated gold nanoclusters. The catalysts thus prepared could be applied to the aerobic oxidation of phenyl boronic acids, alcohols, and silyl enol ethers. We found that the choice of polymers, good and poor solvents for the polymers, metal loadings, heating conditions for cross-linking, and final activation were all crucial for obtaining high-activity catalysts.
- Miyamura, Hiroyuki,Yasukawa, Tomohiro,Kobayashi, Shu
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p. 6039 - 6049
(2015/03/30)
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- Synthesis of novel mast cell-stabilising and anti-allergic 1,2,3,4-tetrahydro-1-naphthalenols and related compounds
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In a continuation of our studies into indan and tetralin systems as novel modulators of allergic and inflammatory phenomena, we have extended our work to include dimers linked via C-C bonds. Of these compounds, 2-Benzyl-2-[2-phenyl-1- ethenyl]-1,2,3,4-tet
- Barlow, James W.,McHugh, Aengus P.,Woods, Orla,Walsh, John J.
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experimental part
p. 1545 - 1554
(2011/05/06)
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- Mechanistic studies on α-trifluoromethylation of ketones via silyl enol ethers and its application to other carbonyl compounds
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(Chemical Equation Presented) Synthesis of α-CF3 carbonyl compounds has been recognized to be difficult up to now because the polarization of CF3δ--Iδ+ is opposite to that of CH3δ+-Iδ-, and this makes it difficult to introduce CF3+ unit to enolates. We recently reported an effective R-trifluoromethylation of ketones by using Et 2Zn with Rh catalyst, but the mechanism has not fully been cleared. Now, we carried out the detailed mechanistic studies and found the involvement of a highly reactive alkylrhodium complex which derived from Et2Zn and RhCl(PPh3)3 in this α-trifluoromethylation. Furthermore, this α-trifluoromethylation was applied to other types of carbonyl compounds in good yields.
- Sato, Kazuyuki,Yuki, Takashi,Yamaguchi, Ryoji,Hamano, Tetsuya,Tarui, Atsushi,Omote, Masaaki,Kumadaki, Itsumaro,Ando, Akira
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supporting information; experimental part
p. 3815 - 3819
(2009/10/01)
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- The effects of C-S and C-Se bonds on torquoselectivity: stereoselective olefination of α-thio and α-selenoketones with ynolates
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Highly Z-selective olefination of acyclic α-thio and α-selenoketones with ynolates has been achieved, and the theoretical calculations of the transition states in the ring-opening of the intermediates, the β-lactone enolates, revealed that the torquoselectivity was controlled by the secondary orbital interactions between the σ orbital of the C-S bond or a lone pair orbital on the S and σ* orbitals of the breaking C-O bond, and the σ orbital of the breaking C-O bond or a lone pair orbital on the O on the ring and the σ* orbitals of the C-S bond. The synthetic applications of the resulting olefins are also shown.
- Yoshikawa, Takashi,Mori, Seiji,Shindo, Mitsuru
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experimental part
p. 8832 - 8838
(2010/04/06)
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- Intramolecular O-H...O hydrogen-bond-mediated reversal in the partitioning of conformationally restricted triplet 1,4-biradicals and amplification of diastereodifferentiation in their lifetimes
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The photoreactivity and nanosecond transient phenomena have been investigated for a rationally designed set of ketones 4-9 in order to gain comprehensive insights concerning the influence of intramolecular hydrogen bonding on (i) the lifetimes of triplet 1,4-biradicals and (ii) the partitioning of the latter between cyclization and elimination. Comparisons of the photochemical results and lifetime data for the biradicals of ketones 6 versus 8 and 7 versus 9 revealed a remarkable influence of hydrogen bonding when superimposed upon steric factors: while 6 and 7 yielded cyclobutanols in poor yields, cyclization was found to be overwhelmingly predominant for 8-anti and moderately so for 9-anti, with a high stereoselectivity in the formation of cyclobutanols (>95% for 8-anti). The diastereochemistry in the case of 8 permitted the occurrence of fragmentation or cyclization almost exclusively (>90% cyclization for 8-anti and >75% elimination for 8-syn). Significantly, the intramolecular hydrogen bonding in the biradicals of 8 and 9 was found to reverse their partitioning between cyclization and elimination compared with the behavior of the biradicals of ketones 3; the ketones 8-anti and 9-anti underwent cyclization in benzene, predominantly leading to cyclobutanols with syn stereochemistry between the C2 and C3 substituents. In accordance with photoproduct profiles, an unprecedented ~2-fold difference in the lifetimes of the intermediate diastereomeric triplet biradicals of ketones 8 in nonpolar solvents (e.g., τsyn = 123 ns and τanti = 235 ns in cyclohexane) was observed via nanosecond laser flash photolysis, while no such difference in lifetimes was found for the triplet biradicals of acetoxy ketones 9. The intriguing diastereodifferentiation in the lifetimes of the diastereomeric triplet 1,4-biradicals of 8 and the product profiles of ketones 6, 7, and 9 are best reconciled via a unified mechanistic picture in which superposition of steric factors over varying magnitudes of O-H...O hydrogen bonding selectively facilitates a particular pathway. In particular, the diastereodifferentiation in the photochemical outcomes for the diastereomers of ketone 8 and in the lifetimes of their triplet biradicals can be understood on the basis of rapid deactivation of the 8-syn triplet biradical via fragmentation and slow cyclization of the 8-anti triplet biradical from chair- and twist-boat-like hydrogen-bonded conformations, respectively. The photolysis in polar aprotic solvents such as DMSO and pyridine was found to reverse the chemoselectivity, yielding reactivity paralleling that of ketones 3, for which the steric factors between the C2 and C3 substituents control the photochemical outcome.
- Moorthy, Jarugu Narasimha,Samanta, Subhas,Koner, Apurba L.,Saha, Satyajit,Nau, Werner M.
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supporting information; experimental part
p. 13608 - 13617
(2009/02/06)
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- Sc(OTf)3-catalyzed smooth tandem [3+2] cycloaddition/ring opening of donor-acceptor cyclopropane 1,1-diesters with enol silyl ethers
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Catalyzed by Lewis acids, donor-acceptor cyclopropane 1,1-diesters reacted with enol silyl ethers to afford 1,6-dicarbonyl compounds in moderate to excellent yields. This supplied a mild carbon-carbon bond-forming method from the ring opening of cyclopropanes. A smooth tandem [3+2] cycloaddition/ring opening process has been clearly proved by an independent experiment.
- Fang, Jie,Ren, Jun,Wang, Zhongwen
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supporting information; body text
p. 6659 - 6662
(2009/04/07)
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- Highly enantioselective synthesis of optically active ketones by iridium-catalyzed asymmetric hydrogenation
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(Chemical Equation Presented) Close to perfect enantioselectivity (up to 99% ee, see scheme) is found for the formation of α-substituted ketones by the asymmetric hydrogenation of enones with an iridium-phosphinooxazoline catalyst. In an operationally simple process, both linear and cyclic substrates react well and afford the desired products in high yields. A wide variety of substituents are tolerated, thus making the method synthetically appealing.
- Lu, Sheng-Mei,Bolm, Carsten
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supporting information; experimental part
p. 8920 - 8923
(2009/05/30)
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- Mild and efficient pentafluorophenylammonium triflate (PFPAT)-catalyzed C-acylations of enol silyl ethers or ketene silyl (Thio)acetals with acid chlorides
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A pentafluorophenylammonium triflate (PFPAT) catalyst (5 mol %) successfully promoted C-acylation of enol silyl ethers with acid chloride to produce various β-diketones (12 examples; 62-92% yield). Similarly, C-acylation of ketene silyl acetals or ketene
- Iida, Akira,Osada, Jun,Nagase, Ryohei,Misaki, Tomonori,Tanabe, Yoo
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p. 1859 - 1862
(2008/02/02)
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- The preparation and reaction of enolates within micro reactors
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Over the past 5 years, interest in the miniaturisation of chemical synthesis has grown rapidly, however in order to facilitate transfer of the technology from its current position as a research tool to industrial applications, a core understanding of the challenges associated with transferring reactions from the macro to the micro domain is required. This paper therefore aims to broach this problem by investigating the application of micro reactors to a range of commonly employed synthetic reactions including acylation, aldol, alkylation, 1,4-conjugate addition (Michael addition) and the Knoevenagel condensation. Comparison of the results obtained with traditional batch techniques enable us to highlight some of the advantages associated with micro reaction technology.
- Wiles, Charlotte,Watts, Paul,Haswell, Stephen J.,Pombo-Villar, Esteban
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p. 10757 - 10773
(2007/10/03)
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- Investigations into the regioselective C-deuteration of acyclic and exocyclic enolates
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Results are reported on the regioselective C-deuteration of a series of related acyclic and exocyclic enolates derived from substituted aryl ketones. We comment on factors, such as the presence of additives and the structural nature of the enolate, that influence the observed C-deuteration and discuss the role of the deuterium donor. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Eames, Jason,Coumbarides, Gregory S.,Suggate, Michael J.,Weerasooriya, Neluka
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p. 634 - 641
(2007/10/03)
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- Reactions of perfluoroalkanesulfonyl chlorides with silyl enol ethers catalyzed by a ruthenium(II) phosphine complex
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Reactions of trifluoromethane- and tridecafluorohexanesulfonyl chlorides with silyl enol ethers have been investigated in the presence of a ruthenium(II) phosphine complex. Perfluoroalkylation and chlorination occurred depending on the substituent of silyl enol ether; i.e. perfluoroalkylated compound was selectively obtained in the reactions with silyl enol ether possessing an electron-withdrawing group, on the other hand, chlorinated compounds selectively formed in the reaction with a silyl enol ether possessing electron-donating group.
- Kamigata, Nobumasa,Udodaira, Kumiko,Shimizu, Toshio
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p. 155 - 168
(2007/10/03)
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- Synthesis and isolation of α-oxo sulfines
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The synthesis of several α-oxo sulfines is discribed. Various α-oxo sulfines can be isolated as such. The Diels-Alder reaction of these sulfines with 1,3-dienes can be catalyzed by Lewis acids.
- Damen, Theodorus J. G.,Zwanenburg, Binne
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p. 319 - 320
(2007/10/03)
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- A simple procedure for the synthesis of 3-(substituted-sulfanyl)-4-hydroxy-6-substituted-pyran-2-ones
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A series of 3-(substituted sulfanyl)-4-hydroxy-6-substituted-pyran-2-ones were synthesized for Human immunodeficiency virus-1 protease inhibition. These compounds were synthesized in a simple and convergent fashion to allow us a rapid preparation of many structurally diversified analogues. Thus the condensation of trimethylsilyl enol ethers of corresponding ketones, with 2-(S-substituted)propane-1,3-dioates afforded the corresponding pyrones in 24-70% isolated yields.
- Para,Ellsworth,Vara Prasad
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p. 1619 - 1624
(2007/10/02)
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- Mechanism of Arylation of Nucleophiles by Aryllead Triacetates. Part 2. Support for a Ligand Coupling Process and X-Ray Molecular Structure of (p-Methoxyphenyl)-α-methylphenacyllead(IV) Diacetate
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In the presence of boron trifluoride-diethyl ether complex p-methoxyphenyllead triacetate 4 and the propiophenone silyl enol ether 6 were found to undergo a rapid reaction to give (p-methoxyphenyl)-α-methylphenacyllead diacetate 9 in high yield.Analogous products, 5, 10 and 11, respectively, were formed when the silyl enol ethers of acetophenone, butyrophenone and isobutyrophenone were treated under the same conditions with aryllead compound 4.The diorganolead diacetates 9, 10 and 11 were relatively unstable, giving a number of products when heated at 60 deg C in chloroform.In each case there was significant elimination of Pb(OAc)2, with formation of the product of ligand coupling, the deoxybenzoin. α-Methylphenacyl(o-prop-2-enyloxy)phenyllead diacetate 21, which was produced to probe the mechanism of the coupling reaction, behaved similarly to compound 9, giving no dihydrobenzofuran derivatives.Therefore, it would appear that aryl free radicals are most probably not produced in these thermal reactions, and a ligand-coupling mechanism is proposed.
- Morgan, Jacqueline,Buys, Irmi,Hambley, Trevor W.,Pinhey, John T.
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p. 1677 - 1682
(2007/10/02)
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- Synthesis and 13C FT NMR spectroscopy of furan-2,3-dione derivatives
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Substituted furan-2,3-diones were obtained by condensation of oxalyl chloride with silyl enol ether of para-substituted acetophenones (R = H, CH3, OCH3, Cl, Br, F), propiophenone, 1-tetralone, 6-methoxytetralone and 1-benzosuberone.The spectroscopic data obtained from IR, UV, 1H and 13C NMR studies are quite similar whichever are the substituents. furan-2,3-dione / 1H and 13C NMR / UV and IR spectra
- Hnach, M.,Aycard, J. P.,Zineddine, H.
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p. 393 - 396
(2007/10/02)
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- A regiodefined synthesis of α-trimethylsilyl ketones catalyzed by rhodium(I) hydride complex
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Regiodefined synthesis of α-trimethylsilyl ketones is attained by one of three different routes: isomerization of β-trimethylsilyl allyl alcohols (route A), isomerization of β'-trimethylsilyl allyl alcohols (route B), and dehydrogenation of β-trimethylsil
- Sato, Susumu,Matsuda, Isamu,Izumi, Yusuke
-
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- Pyridylseleno Group in Organic Synthesis. Preparation and Oxidation of α-(2-Pyridylseleno) Carbonyl Compounds Leading to α,β-Unsaturated Ketones and Aldehydes
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α-(2-Pyridylseleno) carbonyl compounds (A) were prepared by the reaction of ketones or aldehydes with 2-pyridylselenenyl bromide under various conditions (acidic, basic, or after conversion to silyl enol ethers) in good to excellent yields.Oxidation of A thus prepared affords α,β-unsaturated carbonyl compounds in excellent yields even in the cases where satisfactory results were not obtained by the oxidation of the corresponding α-phenylseleno carbonyl compounds.These results indicate that the 2-pyridylseleno group is a better leaving group than the phenylseleno group in selenoxide elimination leading to enones.
- Toshimitsu, Akio,Owada, Hiroto,Terao, Keiji,Uemura, Sakae,Okano, Masaya
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p. 3796 - 3800
(2007/10/02)
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- Carbon-Carbon Bond Formation by the Use of Chloroiodomethane as a C1 Unit. III. A Convenient Synthesis of the Mannich Base from Enol Silyl Ether by a Combination of Chloroiodomethane and N,N,N',N'-Tetramethylmethanediamine
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The Mannich dimethylaminomethylation of carbonyl compounds is conveniently carried out via enol trimethylsilyl ethers by a combination of chloroiodomethane (CH2ClI) and N,N,N',N'-tetramethylmethanediamine (TMMD) in DMSO as the solvent at ambient temperatute.The mechanism of the transformation is discussed on the basis of product analysis and 1H NMR spectral studies.The reagent system CH2ClI/TMMD also provides a convenient route to the Eschenmoser's salt ().
- Miyano, Sotaro,Hokari, Hiroshi,Hashimoto, Harukichi
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p. 534 - 539
(2007/10/02)
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- THE MANNICH REACTION OF CARBONYL COMPOUNDS VIA SILYL ENOL ETHERS BY A COMBINATION OF CHLOROIODOMETHANE AND N,N,N',N'-TETRAMETHYLDIAMINOMETHANE
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The Mannich dimethylaminomethylation of carbonyl compounds is conveniently carried out via trimethylsilyl enol ethers by a combination of chloroiodomethane and N,N,N',N'-tetramethyldiaminomethane in DMSO or DMF as the solvent at ambient temperature.
- Miyano, Sotaro,Hokari, Hiroshi,Mori, Akira,Hashimoto, Harukichi
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p. 1213 - 1214
(2007/10/02)
-