- Benzoazepine-Fused Isoindolines via Intramolecular (3 + 2)-Cycloadditions of Azomethine Ylides with Dinitroarenes
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Aminobenzaldehydes bearing a pendant 3,5-dinitrophenyl group react thermally with N-substituted α-amino acids to form unprecedented benzoazepine-fused isoindolines. The reaction proceeds via a dearomatization/rearomatization sequence involving an intramolecular (3 + 2)-cycloaddition between the in situ formed azomethine ylide and the dinitroarene. Various glycine derivatives are tolerated as well as branched substrates based on cyclic, α-mono-, and α,α-disubstituted amino acids, giving single diastereomers in many cases. The method is scalable and gives products with a nitro group ready for further manipulation.
- Wales, Steven M.,Rivinoja, Daniel J.,Gardiner, Michael G.,Bird, Melissa J.,Meyer, Adam G.,Ryan, John H.,Hyland, Christopher J. T.
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supporting information
p. 4703 - 4708
(2019/06/27)
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- Blue light-promoted photolysis of aryldiazoacetates
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Aryldiazoacetates can undergo photolysis under blue light irradiation (460-490 nm) at room temperature and under air in the presence of numerous trapping agents, such as styrene, carboxylic acids, amines, alkanes and arenes, thus providing a straighforward and general platform for their mild functionalization.
- Jurberg, Igor D.,Davies, Huw M. L.
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p. 5112 - 5118
(2018/06/12)
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- Catalytic Ynamide Oxidation Strategy for the Preparation of α-Functionalized Amides
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A Lewis acid-catalyzed alkyne oxidation strategy has been developed to produce diverse α-functionalized amides from readily and generally available ynamides. An efficient zinc(II)-catalyzed oxidative azidation and thiocyanation has been achieved, providing facile access to synthetically useful α-azido amides and α-thiocyanate amides, respectively. This chemistry can also be extended to oxidative halogenations by employing the 2-halopyridine N-oxide as both the oxidant and the halogen source, and its mechanistic rationale is also supported by density functional theory calculations. Moreover, NaBARF has been demonstrated to catalyze such an alkyne oxidation effectively, thus further excluding the metal carbene pathway in this cascade reaction.
- Pan, Fei,Li, Xin-Ling,Chen, Xiu-Mei,Shu, Chao,Ruan, Peng-Peng,Shen, Cang-Hai,Lu, Xin,Ye, Long-Wu
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p. 6055 - 6062
(2016/09/09)
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- Iridium porphyrin catalyzed N-H insertion reactions: Scope and mechanism
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Ir(TTP)CH3 catalyzed N-H insertion reactions between ethyl diazoacetate (EDA) or methyl phenyldiazoacetate (MPDA) and a variety of aryl, aliphatic, primary, and secondary amines to generate substituted glycine esters with modest to high yields. Aniline substrates generally gave yields above 80%, with up to 105 catalyst turnovers, and without slow addition of the diazo reagent. Good yields were also achieved with aliphatic amines, though higher catalyst loadings and slow addition of the amine were necessary in some cases. Primary amines reacted with EDA to generate both single- and double-insertion products, either of which could be produced selectively in high yield with the proper choice of stoichiometric ratios and reaction temperature. Notably, mixed trisubstituted amines, RN(CH2CO2Et) (CHPhCO2Me), were generated from the insertion of 1 equiv of EDA and 1 equiv of MPDA into primary amines. The N-H insertion mechanism was examined using substrate competition studies, trapping experiments, and multiple spectroscopic techniques. Substrate competition studies using pairs of amines with EDA or MPDA revealed Hammett correlations with respective slopes of ρ = 0.15 and ρ+ = -0.56 as well as kinetic isotope ratios of k H/kD = 1.0 ± 0.2 and 2.7 ± 0.2. Competitive amine binding to the iridium center was demonstrated by kinetics and equilibrium binding studies. Equilibrium binding constants ranged from 102 to 105. Monitoring the reaction by absorption spectroscopy revealed a transient metalloporphyrin complex. The lifetime of this species was dependent on the nature of the amine substrate, which suggests that the catalytic cycle proceeds through a metal-ylide intermediate.
- Anding, Bernie J.,Woo, L. Keith
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p. 2599 - 2607
(2013/06/26)
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- OXAZOLE COMPOUNDS, COMPOSITIONS AND METHODS OF USE
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The present invention relates generally to compounds represented in Formula (I), pharmaceutical compositions comprising them and methods of treating of diseases or disorders such as cancer.
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Page/Page column 38
(2010/01/07)
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- A novel four-component synthesis of N-substituted amino acid esters
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A library of N-substituted amino acid esters was synthesized using a solid phase bound organic isocyanide that provides a C1 synthon to the final molecule. This novel four-component, one-pot reaction delivers the final products in acceptable yields with high purities of the crude reaction products, facilitating the final purification. The preparation of the isocyano resin is also described the intermediates being controlled by ATR-spectroscopy.
- Henkel, Bernd,Weber, Lutz
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p. 1877 - 1879
(2007/10/03)
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- Novel formation and crystal structure of 2-(2,2,2-trifluoroethylidene)-6-trifluoro-methyl-2,3-dihydro-4H-1,4-oxazin-3- ones from N-acetyl-N-alkyl-α-amino acids
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The title compounds (2a-g) were formed from N-acetyl-N-alkyl-α-amino acids (1a-g) on treatment with trifluoroacetic anhydride in the presence of pyridine. The structure of the product (2a) was determined by single crystal X-Ray analysis.
- Kawase, Masami,Saito, Setsuo,Kikuchi, Hiroyuki,Miyamae, Hiroshi
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p. 2185 - 2195
(2007/10/03)
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- STUDIES WITH COENZYME MODEL SYSTEMS
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The chemistry and applications of models of tetrahydrofolate and pyridine nucleotide coenzymes are discussed.
- Pandit, U. K.
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p. 987 - 994
(2007/10/02)
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