- Synthetic Scope of Br?nsted Acid-Catalyzed Reactions of Carbonyl Compounds and Ethyl Diazoacetate
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The comprehensive study of the reactions of carbonyl compounds and ethyl diazoacetate in the presence of a Br?nsted acid catalyst is described. In result, a broad range of 3-oxo-esters were synthesized from a variety of ketones and aliphatic aldehydes by 1,2-aryl/alkyl/hydride shift. Aryl-methyl ketones produced only aryl-migrated products, whereas other ketones yielded a mixture of products. For diaryl ketones, the identity of two inseparable migrated products was confirmed by two-dimensional NMR spectroscopy.
- Rahaman, Mizzanoor,Ali, M. Shahnawaz,Jahan, Khorshada,Hinz, Damon,Belayet, Jawad Bin,Majinski, Ryan,Hossain, M. Mahmun
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p. 6138 - 6147
(2021/05/06)
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- Copper-Mediated Deuterotrifluoromethylation of α?Diazo Esters
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A copper-mediated deuterotrifluoromethylation of α?diazo esters under the promotion of deuterium oxide (D2O) has been developed for the synthesis of deuterium-labeled trifluoromethyl compounds. This deuterotrifluoromethylation reaction is of broad scope and can afford the deuterated products with higher than 99% isotopic purity. Moreover, the results of this investigation also provide some experimental evidences to support our previously proposed trifluoromethylation mechanism.
- Hu, Mingyou,Xie, Qiqiang,Li, Xinjin,Ni, Chuanfa,Hu, Jinbo
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supporting information
p. 469 - 472
(2016/05/24)
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- gem-Difluoroolefination of Diazo Compounds with TMSCF3 or TMSCF2Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors
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A new olefination protocol for transition-metal-free cross-coupling of two carbene fragments arising from two different sources, namely, a nonfluorinated carbene fragment resulting from a diazo compound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazo compounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazo compounds with TMSCF3, which possesses a narrow substrate scope due to a demanding requirement on the reactivity of diazo compounds and in-situ-generated CuCF3, this transition-metal-free protocol affords a general and efficient approach to various disubstituted 1,1-difluoroalkenes, including difluoroacrylates, diaryldifluoroolefins, as well as arylalkyldifluoroolefins. In view of the ready availability of diazo compounds and difluorocarbene reagents and versatile transformations of 1,1-difluoroalkenes, this new gem-difluoroolefination method is expected to find wide applications in organic synthesis.
- Hu, Mingyou,Ni, Chuanfa,Li, Lingchun,Han, Yongxin,Hu, Jinbo
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supporting information
p. 14496 - 14501
(2015/11/27)
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- Copper-mediated trifluoromethylation of α-diazo esters with TMSCF3: The important role of water as a promoter
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Copper-mediated trifluoromethylation of α-diazo esters with TMSCF3 reagent has been developed as a new method to prepare α-trifluoromethyl esters. This trifluoromethylation reaction represents the first example of fluoroalkylation of a non-fluorinated carbene precursor. Water plays an important role in promoting the reaction by activating the "CuCF3" species prepared from CuI/TMSCF3/CsF (1.0:1.1:1.1). The scope of this trifluoromethylation reaction is broad, and its efficiency is demonstrated in the synthesis of a variety of aryl-, benzyl-, and alkyl-substituted 3,3,3-trifluoropropanoates.
- Hu, Mingyou,Ni, Chuanfa,Hu, Jinbo
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supporting information
p. 15257 - 15260
(2012/10/29)
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- A new diversity oriented and metal-free approach to highly functionalized 3H-pyrimidin-4-ones
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A new synthesis of 3H-pyrimidin-4-ones, characterized by four different sets of decorations, is presented. The strategy is based on the synthetic elaboration of readily available α-substituted β-ketoesters that, upon transformation into the corresponding acyl enamines, have been cyclized to give 6H-1,3-oxazin-6-ones. These reactive intermediates have been in turn cleanly converted into highly functionalized pyirimidinones, by treatment with an appropriate primary amine. The whole sequence does not need the use of any metal mediator or catalyst.
- Riva, Renata,Banfi, Luca,Basso, Andrea,Zito, Paola
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experimental part
p. 2107 - 2122
(2011/05/08)
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- Highly regio- and enantioselective organocatalytic conjugate addition of alkyl methyl ketones TO A β-silylmethylene malonate
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(S)-N-(2-Pyrrolidinylmethyl)pyrrolidine/trifluoroacetic acid (3:1) combination catalyzed the direct addition of alkyl methyl ketones to β-dimethyl(phenyl)silylmethylene malonate at the methyl terminal with high yield and excellent regio- and enantioselectivity. The silyl group played crucial roles in regioselection and substrate reactivity.
- Chowdhury, Raghunath,Ghosh, Sunil K.
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supporting information; experimental part
p. 3270 - 3273
(2009/12/01)
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- Asymmetric synthesis of 2-substituted butane-1,4-diols by hydrogenation of homochiral fumaramide derivatives
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Diastereoselective hydrogenation of homochiral fumaramides 1 derived from (2R)-Oppolzer's sultam was observed by analysis of the 1H NMR spectra of the succinamide mixtures with de's of 77-88%. Reduction of these succinamides using LiAlH4 gave the corresponding (2S)-butane-1,4- diols and established that addition of hydrogen takes place selectively on the re-face of fumaramides 1. The stereoselectivity was confirmed by estimating the ee's from the 19F NMR spectra of the Mosher's diesters of the diols. This methodology was applied to the synthesis of selected pyrrolidine natural products in homochiral form.
- Jawaid, Samaila,Farrugia, Louis J.,Robins, David J.
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p. 3979 - 3988
(2007/10/03)
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- One-pot synthesis of α-bromoesters and ketones from β-ketoesters and diketones using supported reagents system
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A simple and efficient method has been developed for the synthesis of α-bromoesters and ketones from β-ketoesters and diketones in one pot using a supported reagents system, CuBr2/Al2O 3-Na2CO3/Al2O3, in which β-ketoester reacts first with CuBr2/Al2O3 and the product, α-bromo-β-ketoester, reacts with Na 2CO3/Al2O3 to give the final product, α-bromoesters in good yields.
- Aoyama, Tadashi,Takido, Toshio,Kodomari, Mitsuo
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p. 1873 - 1876
(2007/10/03)
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- Catalytic radical addition of carbonyl compounds to alkenes by Mn(II)/Co(II)/O2 system
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The radical addition of enolizable carbonyl compounds such as malonates and malononitrile to alkenes was successfully achieved through a catalytic process using the Mn(II)/Co(II)/O2 system to afford the corresponding adducts in fair to good yields. Dimethyl malonate added to 1,5-cyclooctadiene to produce a fused bicycle compound.
- Hirase, Kouji,Iwahama, Takahiro,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 970 - 973
(2007/10/03)
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- Process for the preparation of organic compounds with manganese cataylsts or the like
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A process of the present invention produces an organic compound by allowing a compound containing an electron attractive group of following Formula (1): 1wherein Y is an electron attractive group; and Rb and Rc are each a hydrogen atom or an organic group, where Y, Rb and Rc may respectively be combined with each other to form a ring with an adjacent carbon atom, to react with a compound containing an unsaturated carbon-carbon bond of following Formula (2) or 2wherein Rd, Re, Rf, Rg, Ri and Rj are each a hydrogen atom or an organic group, where Rd, Re, Rf and Rg may respectively be combined to form a ring with one or two adjacent carbon atoms, and Ri and Rj may be combined to form a ring with adjacent two carbon atoms, in the presence of oxygen and a catalytic compound of a Group 5, 6, 7, 8 or 9 element of the Periodic Table of Elements to yield a compound of following Formula (3) or (8): 3wherein Z is a hydrogen atom or a hydroxyl group; and Y, Rb, Rc, Rd, Re, Rf, Rg, Ri and Rj have the same meanings as defined above. This process can efficiently produce a compound having an alkyl group or alkenyl group bonded at the alpha position of an electron attractive group, or a derivative thereof, by catalytic radical addition reaction.
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- PROCESS FOR THE PREPARATION OF ORGANIC COMPOUNDS WITH MANGANESE CATALYSTS OR THE LIKE
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A process of the present invention produces an organic compound by allowing a compound containing an electron attractive group of following Formula (1):wherein Y is an electron attractive group; and Rb and Rc are each a hydrogen atom or an organic group, where Y, Rb and Rc may respectively be combined with each other to form a ring with an adjacent carbon atom, to react with a compound containing an unsaturated carbon-carbon bond of following Formula (2) or (7):wherein Rd, Re, Rf, Rg, Ri and Rj are each a hydrogen atom or an organic group, where Rd, Re, Rf and Rg may respectively be combined to form a ring with one or two adjacent carbon atoms, and Ri and Rj may be combined to form a ring with adjacent two carbon atoms, in the presence of oxygen and a catalytic compound of a Group 5, 6, 7, 8 or 9 element of the Periodic Table of Elements to yield a compound of following Formula (3) or (8):wherein Z is a hydrogen atom or a hydroxyl group; and Y, Rb, Rc, Rd, Re, Rf, Rg, Ri and Rj have the same meanings as defined above. This process can efficiently produce a compound having an alkyl group or alkenyl group bonded at the alpha position of an electron attractive group, or a derivative thereof, by catalytic radical addition reaction.
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