- Synthesis of new bipyridine N,N′-dioxides and their application in asymmetric allylation of benzaldehyde and aldol addition to acetophenone
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Abstract: Two methods for the synthesis of new axially chiral bipyridine N,N′-dioxides based on catalytic [2+2+2] cyclotrimerization of diynes with nitriles were developed. The N,N′-dioxides were used as catalysts in enantioselective allylation of benzaldehyde with allyltrichlorosilane and aldol reaction of trichlorosilyl ketene acetal of methyl acetate with acetophenone. Graphical abstract: [Figure not available: see fulltext.].
- Bedná?ová, Eva,Ne?as, David,Císa?ová, Ivana,Du?ek, Michal,Lamaty, Frédéric,Kotora, Martin
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- Hydroxy-Directed Amidation of Carboxylic Acid Esters Using a Tantalum Alkoxide Catalyst
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We describe herein a new strategy for the chemoselective synthesis of amides by using a metal-catalyzed hydroxy-directed reaction. A hydroxy group located at the β-position of an ester group promoted the activation of a carbonyl group with a tantalum alkoxide catalyst followed by amidation reactions, leading to a wide variety of β-hydroxyamides with excellent chemeselectivity. The chemoselective amidation strategy can be extended to the catalytic synthesis of dipeptide derivatives, which remains challenging research subjects in modern organic synthesis.
- Tsuji, Hiroaki,Yamamoto, Hisashi
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supporting information
p. 14218 - 14221
(2016/11/13)
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- Photoaddition reactions of acetylpyridines with silyl ketene acetals: SET vs [2 + 2]-cycloaddition pathways
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Photoaddition reactions of silyl ketene acetals with 2-, 3- and 4-acetylpyridine have been explored. The results show that the acetylpyridines react with an electron rich, dimethyl-substituted silyl ketene acetal via a pathway in which excited state singl
- Cho, Dae Won,Park, Hea Jung,Yoon, Ung Chan,Lee, Hyang-Yeol,Mariano, Patrick S.
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p. 10304 - 10313
(2013/01/15)
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- Base-catalyzed dehydrogenative Si-o coupling of dihydrosilanes: Silylene protection of diols
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The direct dehydrogenative coupling of 1,3- and 1,4-diols and dihydrosilanes is efficiently catalyzed by CsO(10 mol%), cleanly affording six- and seven-membered 1,3-dioxo-2-silacycles with dihydrogen as the sole by-product. Conversely, 1,2-diols do not yield the expected 1,3-dioxo-2- silacyclopentanes, essentially forming cyclic disiloxanes instead. Aside from the synthetic convenience, the procedure itself is also useful for straight-forward diol derivatization prior to GLC analysis. Georg Thieme Verlag Stuttgart · New York.
- Grajewska, Agnieszka,Oestreich, Martin
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supporting information; experimental part
p. 2482 - 2484
(2010/11/18)
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- Iron-catalyzed oxidative addition of alkoxycarbonyl radicals to alkenes with carbazates and air
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Clean and simple: Alkoxycarbonyl radicals generated from carbazates by iron catalysis in air underwent addition to a variety of alkenes to give the corresponding β-hydroxyesters (see scheme). The simple experimental procedure for this transformation has the added advantage that the reagents are environmentally friendly. R1,R2=alkyl, alkynyl, aryl, CO2Et; [Fe(Pc)]=iron phthalocyanine. Copyright
- Taniguchi, Tsuyoshi,Sugiura, Yuki,Zaimoku, Hisaaki,Ishibashi, Hiroyuki
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supporting information; experimental part
p. 10154 - 10157
(2011/02/24)
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- Ni-catalyzed activation of α-chloroesters: a simple method for the synthesis of α-arylesters and β-hydroxyesters
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Coupling reactions of α-chloroesters with aryl halides (α-arylation) or carbonyl compounds (Reformatsky) using nickel catalyst allow, under mild conditions, the preparation of various functionalized aryl propionic acid derivatives or β-hydroxyesters. In the synthesis of aryl propionic acid derivatives, the process is efficient with aryl halides bearing either electron-withdrawing or electron-donating groups.
- Durandetti, Muriel,Gosmini, Corinne,Périchon, Jacques
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p. 1146 - 1153
(2007/10/03)
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- Iron-catalysed Reformatsky-type reactions
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A Reformatsky-type reaction has been developed using iron catalysis in acetonitrile or DMF. Reduction of iron(II) bromide by manganese metal in acetonitrile provides a low-valent iron catalyst, which is the active species; under these conditions, α-chloro
- Durandetti, Muriel,Perichon, Jacques
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p. 1542 - 1548
(2007/10/03)
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- Lewis base catalyzed, enantioselective aldol addition of methyl trichlorosilyl ketene acetal to ketones
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The catalytic enantioselective addition of an acetate enolate equivalent to ketones is described. Methyl trichlorosilyl ketene acetal reacts with a wide range of ketones in the presence of pyridine N-oxide to afford the aldol addition products in excellen
- Denmark, Scott E.,Fan, Yu,Eastgate, Martin D.
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p. 5235 - 5248
(2007/10/03)
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- Some uses of mischmetall in organic synthesis
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Mischmetall, an alloy of the light lanthanides, has been used in a variety of organic reactions, either as a coreductant in samarium(II)-mediated reactions (Barbier and Grignard-type reactions, pinacolic coupling reactions) or as the promoter of Reformatsky-type reactions. It has been also employed as the starting material for easy syntheses of lanthanide trihalides, the reactivity of which has been explored in Imamoto and Luche-Fukuzawa reactions and in Mukaiyama aldol reactions.
- Lannou, Marie-Isabelle,Hélion, Florence,Namy, Jean-Louis
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p. 10551 - 10565
(2007/10/03)
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- Iron-mediated electrochemical reaction of α-chloroesters with carbonyl compounds
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(Matrix presented) Reformatsky-type reactions have been performed efficiently using an electroassisted iron-complex catalysis. Valuable product such as β-hydroxyesters, ketones or nitriles are thus prepared with high yields.
- Durandetti, Muriel,Meignein, Clothilde,Perichon, Jacques
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p. 317 - 320
(2007/10/03)
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- Catalytic, enantioselective aldol additions to ketones
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Catalytic, enantioselective additions of a trichlorosilyl ketene acetal to ketones have been demonstrated. The trichlorosilyl enolate of methyl acetate undergoes a rapid and high-yielding aldol addition to a wide range of ketones (aromatic, olefinic, acet
- Denmark, Scott E.,Fan, Yu
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p. 4233 - 4235
(2007/10/03)
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- Convenient Synthetic Sequence for the Preparation of Indanones
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A convenient and general methods is reported for the synthesis of indanones from aryl ketones or aldehydes.
- Smonou, Ioulia,Orfanopoulos, Michael
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p. 1387 - 1397
(2007/10/02)
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- Electroreductive Ring-Opening of α,β-Epoxy Carbonyl Compounds and Their Homologues through Recyclable Use of Diphenyl Diselenide or Diphenyl Ditelluride as a Mediator
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A novel access to β-hydroxy carbonyl compounds from the corresponding α,β-epoxy compounds has been attained through the recyclable use of diphenyl diselenide or diphenyl ditelluride as an electroreduction mediator in a MeOH-NaClO4-(Pt) system. α,β-Epoxy ketones are converted to the corresponding aldols in the presence of malonic esters.Similarly, α,β-epoxy esters and nitriles can be reduced to the corresponding β-hydroxy compounds in the presence of acetic acid.
- Inokuchi, Tsutomu,Kusumoto, Masahiko,Torii, Sigeru
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p. 1548 - 1553
(2007/10/02)
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- ELECTROREDUCTIVE COUPLING OF METALLYLCHLORIDE OR METHYL CHLOROACETATE WITH CARBONYL COMPOUNDS CAATLYZED BY NICKEL BIPYRIDINE COMPLEXES
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An efficient electrosynthesis of homoallyl alcohols or β-hydroxy esters in the presence of catalytic amounts of the NiBr2(2,2'-bipyridine) complex has been developed from mixed electrolysis of metellylchloride, or methyl chloroacetate with several carbonyl compounds, using a one-compartment cell equiped with a sacrificial zinc anode.
- Sibille, Soline,d'Incan, Esther,Leport, Luis,Massebiau, Marie-Claude,Perichon, Jacques
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