- Strategic design and refinement of Lewis acid-base catalysis by rare-earth-metal-containing polyoxometalates
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Efficient polyoxometalate (POM)-based Lewis acid-base catalysts of the rare-earth-metal-containing POMs (TBA6RE-POM, RE = Y3+, Nd3+, Eu3+, Gd3+, Tb3+, or Dy 3+) were designed and
- Suzuki, Kosuke,Sugawa, Midori,Kikukawa, Yuji,Kamata, Keigo,Yamaguchi, Kazuya,Mizuno, Noritaka
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- Easily accessible lithium compound catalyzed mild and facile hydroboration and cyanosilylation of aldehydes and ketones
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Simple and readily accessible lithium compounds such as 2,6-di-tert-butyl phenolate lithium (1a), 1,1′ dilithioferrocene (1b) and nacnac lithium (1c) are found to be efficient single site catalysts for hydroboration of a range of aldehydes and ketones wit
- Bisai, Milan Kumar,Das, Tamal,Vanka, Kumar,Sen, Sakya S.
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- Rasta resin-PPh3BnCl and its use in chromatography-free carbonyl cyanosilylation reactions
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Rasta resin-PPhnCl, a new heterogeneous polystyrene-based phosphonium salt, has been synthesized and used to catalyze cyanosilylation reactions of aldehydes and ketones. It was found to be more efficient as a catalyst than a similar heterogeneous phosphon
- Teng, Yan,Toy, Patrick H.
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- Methyltriphenylphosphonium iodide catalyzes the addition of trimethylsilyl cyanide to aldehydes
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Methyltriphenylphosphonium iodide catalyzes the formation of cyanohydrin trimethylsilyl ethers of aliphatic, aromatic and heterocyclic aldehydes.
- Córdoba, Rubén,Plumet, Joaquín
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- Synthesis of magnetically recoverable imidazolium hydrogen carbonate and its application as an N-heterocyclic carbene catalyst to cyanosilylation of aldehydes and ketones
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We prepared a magnetically recoverable imidazolium hydrogen carbonate by immobilizing an imidazolium hydrogen carbonate on magnetite and applied it as an N-heterocyclic carbene catalyst to the cyanosilylation of aldehydes and ketones. By employing the magnetite-supported imidazolium hydrogen carbonate as a catalyst, the cyanosilylation proceeded at 60?°C to provide the corresponding trimethylsilylated cyanohydrin in a fair chemical yield. Moreover, after the reaction, the magnetic catalyst was readily recovered by use of an external magnet and could be reused up to five times.
- Fujii, Akira,Choi, Jun-Chul,Fujita, Ken-ichi
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- Cyanosilylation of carbonyl compounds with trimethylsilyl cyanide catalyzed by an yttrium-pillared silicotungstate dimer
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An yttrium-pillared silicotungstate dimer (see picture) catalyzes the cyanosilylation of structurally diverse ketones and aldehydes with trimethylsilyl cyanide (TMSCN). The reactions proceed selectively and afford the corresponding cyanohydrin trimethylsi
- Kikukawa, Yuji,Suzuki, Kosuke,Sugawa, Midori,Hirano, Tomohisa,Kamata, Keigo,Yamaguchi, Kazuya,Mizuno, Noritaka
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- OXIDATION OF α,β-UNSATURATED ALDEHYDES
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A variety of methods for the conversion of α,β-unsaturated aldehydes to the corresponding acids have been explored.The best approach uses sodium chlorite and gives the desired transformation even in systems where steric hindrance and/or sensitive functionality are present.
- Bal, Balkrishna S.,Childers, Wayne E.,Pinnick, Harold W.
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- Inorganic/organic salts as heterogeneous basic catalysts for cyanosilylation of carbonyl compounds
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The addition of TMSCN to carbonyl compounds catalyzed by K 2CO3 as heterogeneous catalyst gave the corresponding cyanohydrin trimethylsilyl ethers from 20 minutes to 24 hours with 62% to 99% yields without solvent at room temperature
- He, Bin,Li, Yan,Feng, Xiaoming,Zhang, Guolin
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- A tricyclic aluminum alkoxide catalyst for aldehyde trimethylsilylcyanation
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Trimethylsilylcyanation of aldehydes is efficiently accomplished with a low concentration of catalyst 1 under mild conditions in acetonitrile. This protocol tolerates a variety of electron-rich, neutral, and deficient aryl, heterocyclic, and alkyl aldehyd
- Raders, Steven M.,Verkade, John G.
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- Trimethylsilylcyanation of aldehydes and ketones catalyzed by diorganotin dichlorides
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Dibutyltin dichloride and diphenyltin dichloride functioned as effective catalysts for the trimethylsilylcyanation of aldehydes and ketones. Isolated yields ranged from 71% to 97%.
- Whitesell, James K.,Apodaca, Richard
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- An improved synthesis of cyanohydrins in the presence of solid LiClO4 under solvent-free conditions
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Several cyanohydrins were synthesized by the reaction of trimethylsilyl cyanide with carbonyl compounds in the presence of solid lithium perchlorate in high yields under solvent-free conditions.
- Azizi, Najmedin,Saidi, Mohammad R.
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- Dodecatungestophosphoric acid (H3PW12O40) as a solid green Br?nsted acid catalyzes high yielding and efficient trimethylcyanosylilation reactions of aldehydes and ketones by trimethylsilyl cyanide
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An efficient solvent-free method is described for the addition of TMSCN to carbonyl groups employing dodecatungestophosphoric acid (H3PW 12O40) as a heterogeneous and environmentally benign catalyst. By this method, aromat
- Firouzabadi, Habib,Iranpoor, Nasser,Jafari, Abbas Ali
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- Fe(Cp)2PF6: An efficient catalyst for cyanosilylation of carbonyl compounds under solvent free condition
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An efficient method for the addition of trimethylsilyl cyanide (TMSCN) to various aldehydes and ketones has been described using Fe(Cp)2PF6 (2.5 mol%) as a catalyst under solvent free condition. Excellent yields of trimethylsilylethe
- Khan, Noor-ul H.,Agrawal, Santosh,Kureshy, Rukhsana I.,Abdi, Sayed H.R.,Singh, Surendra,Jasra, Raksh V.
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- Lithium chloride: An active and simple catalyst for cyanosilylation of aldehydes and ketones
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LiCl acts as a highly effective catalyst for cyanosilylation of various aldehydes and ketones to the corresponding silylated cyanohydrins. The reaction proceeds smoothly with a substrate/catalyst molar ratio of 100-100 000 at 20-25 °C under solvent-free conditions. α,β-Unsaturated aldehydes are completely converted to the 1,2-adducts. The cyanation products can be isolated by direct distillation of the reaction mixture.
- Kurono, Nobuhito,Yamaguchi, Masayo,Suzuki, Ken,Ohkuma, Takeshi
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- Gold(III)-catalyzed cyanosilylation of ketones and aldehydes
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Gold(III) chloride was found to be a highly efficient catalyst for the cyanosilylation of various ketones and aldehydes. The reactions were complete within 30 minutes at room temperature in the presence of only one mol% gold(III) chloride, yielding the co
- Woo, Kyung Cho,Sung, Min Kang,Medda, Amiya K.,Lee, Jungkyu K.,Choi, Insung S.,Lee, Hee-Seung
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- Gold-catalyzed cyanosilylation reaction: Homogeneous and heterogeneous pathways
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Gold had been considered to be an extremely inert metal, but recently it was found that nanometersized gold particles on metal-oxide supports acted as catalysts for simple organic reactions, such as oxidation and hydrogenation, even at or below room tempe
- Cho, Woo Kyung,Lee, Jungkyu K.,Kang, Sung Min,Chi, Young Shik,Lee, Hee-Seung,Choi, Insung S.
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- Potassium exchanged zirconium hydrogen phosphate as heterogeneous catalyst in cyanosilylation of carbonyl compounds
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Layered zirconium hydrogen phosphate exchanged with potassium ion was found to be an efficient heterogeneous catalyst for cyanosilylation of carbonyl compounds.
- Curini, Massimo,Epifano, Francesco,Marcotullio, Maria Carla,Rosati, Ornelio,Rossi, Monia
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- A Tin-tungsten mixed oxide as an efficient heterogeneous catalyst for C-C Bond Bond-Forming reactions
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The tin-tungsten mixed oxide prepared by the calcination of the tin-tungsten hydroxide precursor with a Sn/W molar ratio of 2 at 800 °C (SnW2-800) acts as an effective and reusable solid catalyst for C-C bond-forming reactions, such as the cyclization of citronellal, the Diels-Alder reaction, and the cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (TMSCN). Various kinds of structurally diverse aliphatic, aromatic, and unsaturated, heteroatom-containing substrates could be converted into the desired products in high to excellent yields. The observed catalyses for these reactions were truly heterogeneous and the recovered catalyst could be reused several times without an appreciable loss of its high catalytic performance. The Bronsted acid sites generated on the aggregated polytungstate species on SnW2-800 likely play an important role in the C-C bond-forming reactions.
- Ogasawara, Yoshiyuki,Uchida, Sayaka,Yamaguchi, Kazuya,Mizuno, Noritaka
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- A novel yttrium-based metal-organic framework for the efficient solvent-free catalytic synthesis of cyanohydrin silyl ethers
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A new porous metal-organic framework (MOF) with the chemical formula [Y5L6(OH)3(DMF)3]·5H2O (1) (where L = 3-amino-4-hydroxybenzoate) has been prepared by a solvothermal procedure. The structural char
- Cepeda, Javier,Echenique-Errandonea, Estitxu,Fernández, Ignacio,Pérez, Juana M.,Rodríguez-Diéguez, Antonio,Rojas, Sara,Seco, José M.
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supporting information
p. 11720 - 11724
(2021/09/06)
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- Cooperative thiourea-Bronsted acid organocatalysis: Enantioselective cyanosilylation of aldehydes with TMSCN
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We report a new thiourea - Bronsted acid cooperative catalytic system for the enantioselective cyanosilylation of aldehydes with yields up to 90% and enantioselectivities up to 88%. The addition of an achiral acid was found to be crucial for high asymmetric induction. Mechanistic investigations using a combination of NMR, ESI-MS, and density functional theory computations (including solvent corrections) at the M06/6-31G(d,p) level of theory suggest that the key catalytic species results from the cooperative interaction of bifunctional thioureas and an achiral acid that form well-defined chiral hydrogen-bonding environments.
- Zhang, Zhiguo,Lippert, Katharina M.,Hausmann, Heike,Kotke, Mike,Schreiner, Peter R.
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experimental part
p. 9764 - 9776
(2012/01/03)
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- Dibutyltin dibromide-catalyzed trimethylsilylcyanation of aldehydes and imines
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Dibutyltin dibromide efficiently catalyzes addition of tri-methylsilyl cyanide to aldehydes and aldimines. Various tri-methylsilylated cyanohydrins and α-aminonitriles are obtained in moderate to high yield by this method. Copyright
- Yanagisawa, Akira,Matsumoto, Takuya,Arai, Takayoshi,Yoshida, Kazuhiro
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scheme or table
p. 336 - 337
(2010/01/16)
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- An expeditious synthesis of cyanohydrin trimethylsilyl ethers using tetraethylammonium 2-(carbamoyl)benzoate as a bifunctional organocatalyst
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Phthalimide and tetraethylammonium hydroxide react via an unusual pathway to afford tetraethylammonium 2-(carbamoyl)benzoate (TEACB) which is of interest as a bifunctional organocatalyst. TEACB (0.5 mol %) was found to catalyze the addition of trimethylsi
- Dekamin, Mohammad G.,Sagheb-Asl, Solmaz,Reza Naimi-Jamal
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scheme or table
p. 4063 - 4066
(2009/10/11)
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- Efficient control of π-alkyne and vinylidene complex pathways for the W(CO)5(L)-catalyzed synthesis of two types of nitrogen-containing bicyclic compounds
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When ω-acetylenic dienol silyl ethers containing NMs part in the tether were treated with a catalytic amount of W(CO)6 under photoirradiation, 2-azabicyclo[3.3.0]octanes were obtained in good yield via π-alkyne complexes. On the other hand, treatment of the same substrates with a catalytic amount of W(CO)6 in the presence of n-Bu3N under the same reaction conditions gave 3-azabicyclo[3.3.0]octanes in good yield exclusively via vinylidene complexes. Thus, the π-alkyne and vinylidene complex pathways are easily controlled by using a catalytic amount of W(CO)5(L) and an amine. Copyright
- Onizawa, Yuji,Kusama, Hiroyuki,Iwasawa, Nobuharu
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p. 802 - 803
(2008/09/20)
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- Cyanosilylation of aldehydes and ketones catalyzed by nanocrystalline magnesium oxide
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Cyanosilylation of various aldehydes and ketones with TMSCN proceeded smoothly under mild conditions to give the corresponding cyanohydrin trimethylsilyl ethers in the presence of nanocrystalline magnesium oxide. The cyanohydrin trimethylsilyl ethers of aldehydes produced cyanohydrins in good to high yields on treatment with 2 N HCl. 29Si NMR spectral evidence proved that the reaction proceeds through the hypervalent silicate species by coordination to O2-/O- (Lewis basic site) of nanocrystalline magnesium oxide. Copyright Taylor & Francis Group, LLC.
- Lakshmi Kantam,Mahendar, Koosam,Sreedhar, Bojja,Vijay Kumar,Choudary
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experimental part
p. 3919 - 3936
(2009/04/11)
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- Neutral π-nucleophile-catalyzed cyanation of aldehydes and ketones
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1-Methoxy-2-methyl-1-(trimethylsiloxy)propene, a neutral π-nucleophile, was found to be able to efficiently catalyze the cyanation (cyanosilylation and cyanocarbonation) of various aldehydes and ketones, and this study provided the first illustration of u
- Wang, Xiu,Tian, Shi-Kai
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p. 1416 - 1420
(2008/03/11)
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- Organocatalytic activation of TMSCN by basic ammonium salts for efficient cyanation of aldehydes and imines
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Basic ammonium salts act as highly effective catalysts for the cyanosilylation of aldehydes and in Strecker-type aminonitrile synthesis using TMSCN as cyanide source at 25 °C under extremely mild conditions, affording very good to excellent yields of silylated cyanohydrins and α-aminonitriles.
- Raj, I. Victor Paul,Suryavanshi, Gurunath,Sudalai
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p. 7211 - 7214
(2008/03/11)
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- Lewis base catalyzed addition of trimethylsilyl cyanide to aldehydes
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A variety of achiral Lewis bases were found to catalyze the addition of TMSCN to the aldehydes. Among them, phosphines and amines were the most efficient catalysts. In addition, several chiral amines and phosphines were examined in a catalytic, asymmetric
- Denmark, Scott E.,Chung, Won-Jin
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p. 4002 - 4005
(2007/10/03)
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- Highly efficient trialkylsilylcyanation of aldehydes, ketones and imines catalyzed by a nucleophilic N-heterocyclic carbene
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The synthetic utility of N-heterocyclic carbenes was demonstrated by the trialkylsilylcyanation of aldehydes, ketones and imines. In the presence of a catalytic amount of 3a, the reactions with Me3SiCN proceeded smoothly to give the corresponding cyanohydrin trimethylsilyl ethers or amino nitrile derivatives in good to excellent yields.
- Kano, Taichi,Sasaki, Kouji,Konishi, Teppei,Mii, Haruka,Maruoka, Keiji
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p. 4615 - 4618
(2007/10/03)
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- Cyanosilylation of aldehydes catalyzed by N-heterocyclic carbenes
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N-Heterocyclic carbenes produced in situ from salts of imidazolium, benzimidazolium, pyrido[1,2-c]imidazolium, imidazolinium, thiazolium, and triazolium catalyze the addition of trimethylsilylcyanide to aldehydes to yield cyanohydrin trimethylsilyl ethers. The use of C2-symmetric imidazolidenyl carbene derived from (R,R)-1,3-bis[(1-naphthyl)ethyl]imidazolium chloride led to enantioselective cyanosilylation.
- Suzuki, Yumiko,Bakar, M.D., Abu,Muramatsu, Kazuyuki,Sato, Masayuki
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p. 4227 - 4231
(2007/10/03)
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- The substrate spectrum of mandelate racemase: Minimum structural requirements for substrates and substrate model
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Mandelate racemase (EC 5.1.2.2) is one of the few biochemically well-characterized racemases. The remarkable stability of this cofactor-independent enzyme and its broad substrate tolerance make it an ideal candidate for the racemization of non-natural α-hydroxycarboxylic acids under physiological reaction conditions to be applied in deracemization protocols in connection with a kinetic resolution step. This review summarizes all aspects of mandelate racemase relevant for the application of this enzyme in preparative-scale biotransformations with special emphasis on its substrate tolerance. Collection and evaluation of substrate structure-activity data led to a set of general guidelines, which were used as basis for the construction of a general substrate model, which allows a quick estimation of the expected activity for a given substrate.
- Felfer, Ulfried,Goriup, Marian,Koegl, Marion F.,Wagner, Ulrike,Larissegger-Schnell, Barbara,Faber, Kurt,Kroutil, Wolfgang
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p. 951 - 961
(2007/10/03)
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- Solvent-free synthesis of cyanohydrin derivatives catalysed by triethylamine
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A very simple one-step environmentally friendly procedure for the synthesis of O-substituted cyanohydrins from aldehydes and ketones, in the absence of solvent, employing minimum amounts of the corresponding cyanides has been optimised. Aldehydes react more rapidly than ketones using triethylamine as catalyst offering in both cases almost quantitative yields of the corresponding O-trimethylsilyl, O-methoxycarbonyl, O-benzoyl and O-acetyl cyanohydrins. Georg Thieme Verlag Stuttgart.
- Baeza, Alejandro,Najera, Carmen,Retamosa, Ma. De Gracia,Sansano, Jose M.
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p. 2787 - 2797
(2007/10/03)
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- Synthesis of 13C-dehydrocoelenterazine and NMR studies on the bioluminescence of a Symplectoteuthis model
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The bioluminescence of luminous squid (Symplectoteuthis oualaniensis) is presumed to be initiated by the addition of the sulfhydryl residue of a photoprotein to dehydrocoelenterazine (DCL). To clarify this step, a novel synthetic route was established to label DCL with 13C. Dithiothreitol (DTT) and glutathione (GSH) were used as photoprotein models. The addition of DTT and GSH to 13C-labeled DCL gave luminous chromophores. Its structures were confirmed by NMR and MS spectrometry. The DTT adduct emitted light under alkaline condition to produce an oxidized compound. Thus we succeeded in modeling the bioluminescence of a photoprotein with DTT. (C) 2000 Elsevier Science Ltd.
- Kuse, Masaki,Isobe, Minoru
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p. 2629 - 2639
(2007/10/03)
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- Enzymatic Preparation of Optically Active Cyanohydrin Acetates
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A series of cyanohydrin acetates (1)-(47) of widely varying structures, potential chiral building blocks for numerous synthetic applications, has been prepared in good chemical and often high optical yields by enzymatic hydrolysis of their racemic acetates in the presence of an ester hydrolase from Pseudomonas sp.
- Almsick, Andreas van,Buddrus, Joachim,Hoenicke-Schmidt, Petra,Laumen, Kurt,Schneider, Manfred P.
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p. 1391 - 1393
(2007/10/02)
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- Trimethylsilyl Cyanide - A Reagent for Umpolung, XI. On the Ambident Character of Substituted Allylic Anions.
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The dependence of the α/γ-ratio of alkylation products on several factors has been determined with 1-cyano-3-aryl-1-(trimethylsiloxy)allylic anions.Increasing amounts of γ-product are found in more polar solvents, with larger alkali ions, on addition of HMPT, with smaller alkyl groups in the electrophile, and especially with p-cyanophenyl groups.In contrast, temperature and leaving groups have minor effects.On substitution of the O-silyl group by O-methyl and O-ethoxycarbonyl, α-alkylation predominates strongly.The results are compared to known allylic anions.Furthermore, the isomerisation of compounds of type C to type B is described as well as a new addition reaction of cyanoformates to aldehydes.
- Huenig, Siegfried,Reichelt, Helmut
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p. 1772 - 1800
(2007/10/02)
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- A Simple One-Pot Synthesis of Silylated and Acylated Cyanohydrins
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Reaction of variety of aldehydes and ketones with chlorotrimethylsilane and acyl chlorides in the presence of lithium cyanide to give trimethylsilylcyanohydrins and acylcyanohydrins is described.
- Yoneda, Ryuji,Santo, Kazunori,Harusawa, Shinya,Kurihara, Takushi
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p. 1054 - 1055
(2007/10/02)
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- Trimethylsilyl Cyanide - A Reagent for Umpolung, V. Nucleophilic Acylation of Alkylating Reagents with α,β-Unsaturated Aldehydes.
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The readily accessible adducts 3 from α,β-unsaturated aldehydes and trimethylsilyl cyanide react smoothly after deprotonation (LDA) as anions 3A with different alkylating agents in 1-position.Removal of the protective group under mild conditions yields the α,β-unsaturated ketones 5 in 60 - 80 percent overall yield.The stability of anions 3A is increased by an O-triethylsilyl group.Alkylation of 3A in 3-position (partly) is caused by 3-acceptor substituents.Nucleophilic acylation with α-alkoxyaldehydes produces 1,2-diketones via a new route.
- Hertenstein, Ulrich,Huenig, Siegfried,Oeller, Manfred
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p. 3783 - 3802
(2007/10/02)
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