- Effect of Transition Metals on Chemodivergent Cross-Coupling of Acrylamides with Vinyl Acetate via C-H Activation
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A novel chemodivergent cross-coupling of acrylamides and vinyl acetates has been realized via metal-catalyzed vinylic C-H activation. The selective olefinic C-H vinylation and alkenylation reaction was examined with a variety of differently functionalized acrylamides. The reaction efficiently generates a range of highly synthetically valuable butadienes with good functional group tolerance in good to moderate yields. A possible catalytic reaction mechanism involving the chelation-assisted olefinic C-H activation via an acetate-assisted deprotonation pathway is proposed.
- Logeswaran, Ravichandran,Jeganmohan, Masilamani
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supporting information
p. 5679 - 5683
(2021/08/03)
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- Rhodium-Catalyzed Electrooxidative C?H Olefination of Benzamides
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Metal-catalyzed chelation-assisted C?H olefinations have emerged as powerful tools for the construction of functionalized alkenes. Herein, we describe the rhoda-electrocatalyzed C?H activation/alkenylation of arenes. The olefinations of challenging electron-poor benzamides were thus accomplished in a fully dehydrogenative fashion under electrochemical conditions, avoiding stoichiometric chemical oxidants, and with H2 as the only byproduct. This versatile alkenylation reaction also features broad substrate scope and used electricity as a green oxidant.
- Ackermann, Lutz,Struwe, Julia,Zhang, Yan
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supporting information
p. 15076 - 15080
(2020/06/20)
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- PROCESS FOR PREPARING N-METHYL(METH)ACRYLAMIDE
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The invention relates to a process for preparing N-methyl(meth)acrylamide and to the uses thereof.
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Page/Page column 5-6
(2020/02/16)
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- Iridium-catalyzed alkenyl C-H allylation using conjugated dienes
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An iridium-catalyzed C-H allylation of acrylamides with conjugated dienes was developed, using NH-Ts amide as the directing group. The ligand- and additive-free protocol provided a convenient and atom economic synthesis of branched 1,4-diene skeletons, enabling the tolerance of a wide scope of functionalities such as OMe, F, Cl, Br and CF3. The utility of this protocol is also demonstrated by a preparative scale, as well as C-H functionalization of artemisic amide. Furthermore, NH-Ts amide was efficiently removed by methylation and hydrolysis procedures to provide 1,4-dienoic acid.
- Xu, Liangyao,Meng, Keke,Zhang, Jian,Sun, Yaling,Lu, Xiunan,Li, Tingyan,Jiang, Yan,Zhong, Guofu
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supporting information
p. 9757 - 9760
(2019/08/20)
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- Cobalt-Catalyzed Olefinic C-H Alkenylation/Alkylation Switched by Carbonyl Groups
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The first cobalt-catalyzed cross-couplings between olefins has been demonstrated to provide C(alkenyl)-H alkenylation and alkylation products, using complex [Cp?Co(CO)I2]. While coupling partner acrylates afforded conjugated dienoates, α,β-unsaturated ketones led to γ-alkenyl ketones completely, representing a switchable C-H functionalization controlled by different carbonyl groups.
- Li, Tingyan,Shen, Cong,Sun, Yaling,Zhang, Jian,Xiang, Panjie,Lu, Xiunan,Zhong, Guofu
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supporting information
p. 7772 - 7777
(2019/10/10)
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- Exploring the scope of the 29G12 antibody catalyzed 1,3-dipolar cycloaddition reaction
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29G12 is a murine monoclonal antibody programmed to catalyze the regio- and enantioselective 1,3-dipolar cycloaddition reaction between 4-acetamidobenzonitrile N-oxide 1a and N,N-dimethylacrylamide 2a (Toker, J. D.; Wentworth, P., Jr.; Hu, Y.; Houk, K. N.; Janda, K. D. J. Am. Chem. Soc. 2000, 122, 3244). Given the unique nature of 29G12 as a protein biocatalyst for this chemical reaction, we have investigated both the substrate specificity and mechanistic parameters of the 29G12-catalyzed process. These studies have shown that while 29G12 is specific for its dipole substrate Ia, the antibody is highly promiscuous with respect to the dipolarophiles it can process. 29G12 accepts a bulky hydrophobic dipolarophile cosubstrate, with rates of product formation up to 70-fold faster than with the original substrate 2a. In all cases, the respective isoxazoline products are produced with exquisite regio- and stereochemical control (78-98% ee). Comparison between the steady-state kinetic parameters from the 29G12-catalyzed reaction of 1a with the most efficient versus the original dipolarophile cosubstrate (2m and 2a, respectively), reveals that while the effective molarities (EM)s are almost identical (EM (2m) 26 M; EM(2a) 23 M), the affinity of 29G12 for the larger dipolarophile 2m is more than 1 order of magnitude higher than for 2a [Km(2m) 0.44 ± 0.04 mM; Km(2a) 5.8 ± 0.4 mM]. Furthermore, when 2m is the cosubstrate, the affinity of 29G12 for its dipole 1a is also greatly improved [Km(1a) 0.82 ± 0.1 mM compared to Km(1a) 3.4 ± 0.4 mM when 2a is the cosubstrate]. An analysis of the temperature dependence of the 29G12-catalyzed reaction between 1a and 2m reveals that catalysis is achieved via a decrease in enthalpy of activation (ΔΔH? 4.4 kcal mol-1) and involves a large increase in the entropy of activation (ΔΔS? 10.4 eu). The improved affinity of 29G12 for the nitrile oxide Ia in the presence of 2m, coupled with the increase in ΔΔS? during the 29G12-catalyzed reaction between 1a and 2m supports the notion of a structural reorganization of the active site to facilitate this antibody-catalyzed reaction.
- Toker, Jonathan D.,Tremblay, Martin R.,Yli-Kauhaluoma, Jari,Wentworth, Anita D.,Zhou, Bin,Wentworth Jr., Paul,Janda, Kim D.
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p. 7810 - 7815
(2007/10/03)
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- Method of manufacturing N-monosubstituted (meth)acrylamides
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A process for producing N-monosubstituted acrylamides in high yields without forming by-products. The process comprises preparing a β-dialkylamino-(methyl)propionic ester by the reaction of a (meth)-acrylic ester with a specified dialkylamine, converting the formed ester into an N-monosubstituted β-dialkylamino(methyl)propionamide by the reaction thereof with a primary amine in the presence of sodium methoxide, and thermally decomposing the amide under a reduced pressure.
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- Cholinergic agents: Effect of methyl substitution in a series of arecoline derivatives on binding to muscarinic acetylcholine receptors
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Arecoline, arecaidine, and a series of derivatives, differing by the presence or absence of methyl groups at positions on the periphery of the molecule, were prepared, and their binding to muscarinic acetylcholine receptors was tested. On the basis of this study, muscarinic agonism for arecoline series is governed by strict structure-activity relationships, as previously observed for other agonist series. Only minor changes in nitrogen substitution were tolerated in the present series of arecoline derivatives.
- Moos,Bergmeier,Coughenour,Davis,Hershenson,Kester,McKee,Marriott,Schwarz,Tecle,Thomas
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p. 1015 - 1019
(2007/10/02)
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