- HYDROGEN TRANSFER FROM CROTYLTRI-n-BUTYLSTANNANE TO CARBON RADICALS
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Attempted reaction of carbon centered radicals with crotyltri-n-butylstannane leads not to C-C bond formation as with 2-propenyltri-n-butylstannane, but to hydrogen abstraction resulting in production of butadiene and tri-n-butylstannyl radicals.
- Keck, Gary E.,Yates, John B.
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- Niobium-Catalyzed Intramolecular Addition of O-H and N-H Bonds to Alkenes: A Tool for Hydrofunctionalization
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A convenient, versatile, and easy to handle intramolecular hydrofunctionalization of alkenes (C-O and C-N bonds formation) is reported using a novel niobium-based catalytic system. This atom economic and eco-friendly methodology provides an additional synthetic tool for the straightforward formation of valuable building blocks enabling molecular complexity. Various pyran, furan, pyrrolidine, piperidine, lactone, and lactam derivatives as well as spirocyclic compounds are produced in high yields and selectivities.
- Ferrand, Laura,Tang, Yue,Aubert, Corinne,Fensterbank, Louis,Mouriès-Mansuy, Virginie,Petit, Marc,Amatore, Muriel
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supporting information
p. 2062 - 2065
(2017/04/28)
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- Catalytic Synthesis of Saturated Oxygen Heterocycles by Hydrofunctionalization of Unactivated Olefins: Unprotected and Protected Strategies
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A mild, general, and functional group tolerant intramolecular hydroalkoxylation and hydroacyloxylation of unactivated olefins using a Co(salen) complex, an N-fluoropyridinium salt, and a disiloxane reagent is described. This reaction was carried out at ro
- Shigehisa, Hiroki,Hayashi, Miki,Ohkawa, Haruna,Suzuki, Tsuyoshi,Okayasu, Hiroki,Mukai, Mayumi,Yamazaki, Ayaka,Kawai, Ryohei,Kikuchi, Harue,Satoh, Yui,Fukuyama, Akane,Hiroya, Kou
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supporting information
p. 10597 - 10604
(2016/09/04)
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- On the understanding of BF3·Et2O-promoted intra- and intermolecular amination and oxygenation of unfunctionalized olefins
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BF3·Et2O was found to be effective for both intra- and intermolecular amination and oxygenation of unfunctionalized olefins. In the presence of 3 equiv. of BF3·Et2O, intramolecular hydroamination of N-(pent-4-enyl)-p-toluenesulfonamides, N-(hex-5-enyl)-p-toluenesulfonamides, intermolecular hydroamination between sulfonamides and cyclohexene, norbornene or styrene, lactonization of pent-4-enoic acid or hex-5-enoic acid compounds and esterification of cyclohexene with different carboxylic acids all proceeded readily, leading to the corresponding amination or oxygenation products in up to 99% isolated yields. Preliminary NMR experiments and DFT calculations suggested that the intramolecular hydroamination reactions proceeded via a sulfonimidic acid intermediate (N=S-OH), and formation of the corresponding Bronsted acid HF or HBF4 was less likely.
- Yang, Chun-Hua,Fan, Wen-Wen,Liu, Gong-Qing,Duan, Lili,Li, Lin,Li, Yue-Ming
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p. 61081 - 61093
(2015/08/03)
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- Synthesis of β,β-disubstituted γ-butyrolactones by chemo-selective oxidation of 1,4-diols and γ-hydroxy olefins with rucl3/NaIO4
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Substituted γ-butyrolactones represent an important group of structural fragments commonly found in natural products, receptor ligands, and drug molecules. Interest in preparing a library of substituted γ-butyrolactones and finding that limited routes to β-substituted lactones exist, led to the development of an efficient approach for the synthesis of β,β-disubstituted γ-butyrolactones. Readily prepared substituted 1,4-diols and γ-hydroxy olefins were treated with the -RuCl3/NaIO4 oxidation system to provide the target β,β-disubstituted γ-butyrolactones in modest to good yields. The reaction goes through a lactol intermediate that was isolated and characterized for selected compounds. The approach supplies an efficient and versatile method for the synthesis of these important heterocyclic structures. Importantly, the present work is the first report that demonstrates the ability of RuCl3/NaIO4 to selectively oxidize primary hydroxyl groups in the presence of secondary alcohols to prepare lactones in good yields.
- Gao, Rong,Fan, Rong,Canney, Daniel J.
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p. 661 - 665
(2015/03/14)
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- Cationic iron-catalyzed addition of carboxylic acids to olefins
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Cationic iron salts were found to be good catalysts for intraand intermolecular addition of carboxylic acids to olefins, which afforded the corresponding esters in good yields. Copyright
- Komeyama, Kimihiro,Mieno, Yasuhiro,Yukawa, Syotaro,Morimoto, Takayuki,Takaki, Ken
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p. 752 - 753
(2008/02/09)
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- Unusual iodine catalyzed lactonization of γ-methyl-γ,δ-pentenoic acids: A facile synthesis of γ,γ-dimethyl-γ-butyrolactones
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γ,γ-Dimethyl-γ-butyrolactones were exclusively obtained from γ-methyl-γ,δ-pentenoic acids with a catalytic amount of iodine in good yields in methylene chloride.
- Kim, Kyoung Mahn,Ryu, Eung K.
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p. 1441 - 1444
(2007/10/03)
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- REDUCTION OF TELLURIUM - CARBON BONDS OF TELLUROLACTONES AND TELLUROETHERS
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The lactones and cyclic ethers produced in the tellurocyclofunctionalization of unsaturated carboxylic acids and alcohols are efficiently detellurated by tri-n-butyl tin hydride.Trapping of the intermediate free radicals with methyl acrylate leads to the corresponding adducts in moderate to good yields.
- Comasseto, J. V.,Ferraz, H. M. C.,Brandt, C. A.,Gaeta, K. K.
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p. 1209 - 1212
(2007/10/02)
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- CHARACTERIZATION OF NEW OXIDATION PRODUCTS OF THE PERCHLORATE SALT OF THE METHADONE METABOLITE, (+/-)-2-ETHYLIDENE-1,5-DIMETHYL-3,3-DIPHENYLPYRROLIDINE (EDDP)
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The oxidation of (+/-)-2-ethyl-1,5-dimethyl-3,3-diphenylpyrrolinium perchlorate (1, EDDP) with m-chloroperbenzoic acid (MCPBA) afforded diastereomeric 2-(4',4'-diphenylheptan-5'-one-2'-yl)-oxaziridine (2), 4,4-diphenyl-2,5-heptadione (3), and the known compounds 2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline (5, EMDP) and 1,5-dimethyl-3,3-diphenylpyrrolidone (4, DDP). 13C and 1H NMR results for the new compounds and mechanisms for their formation are discussed.
- Abbott, Frank S.,Slatter, J. Gregory,Kang, Gun Il
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p. 245 - 248
(2007/10/02)
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