- N-Ethynylation of Anilides Decreases the Double-Bond Character of Amide Bond while Retaining trans-Conformation and Planarity
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Activated amide bonds have been attracting intense attention; however, most of the studied moieties have twisted amide character. To add a new strategy to activate amide bonds while maintaining its planarity, we envisioned the introduction of an alkynyl group on the amide nitrogen to disrupt amide resonance by nN→Csp conjugation. In this context, the conformations and properties of N-ethynyl-substituted aromatic amides were investigated by DFT calculations, crystallography, and NMR spectroscopic analysis. In contrast to the cis conformational preference of N-ethyl- and vinyl-substituted acetanilides, N-ethynyl-substituted acetanilide favors the trans conformation in the crystal and in solution. It also has a decreased double bond character of the C(O)?N bond, without twisting of the amide. N-Ethynyl-substituted acetanilides undergo selective C(O)?N bond or N?C(sp) bond cleavage reactions and have potential applications as activated amides for coupling reactions or easily cleavable tethers.
- Yamasaki, Ryu,Morita, Kento,Iizumi, Hiromi,Ito, Ai,Fukuda, Kazuo,Okamoto, Iwao
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supporting information
p. 10118 - 10122
(2019/07/05)
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- Enamide-benzyne-[2 + 2] cycloaddition: Stereoselective tandem [2 + 2]-pericyclic ring-opening-intramolecular N-tethered [4 + 2] cycloadditions
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Image Presented Benzyne-[2 + 2] cycloadditions with enamides are described. This effort led to the development of a highly stereoselective tandem [2 + 2] cycloaddition-pericyclic ring-opening-intramolecular-N-tethered-[4 + 2] cycloaddition for rapid assembly of nitrogen heterocycles.
- Feltenberger, John B.,Hayashi, Ryuji,Tang, Yu,Babiash, Eric S.C.,Hsung, Richard P.
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supporting information; experimental part
p. 3666 - 3669
(2011/02/25)
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- INVESTIGATION OF THE STRUCTURES OF AND THE INTRAMOLECULAR INTERACTIONS IN N-VINYLAMIDES BY MEANS OF MULTINUCLEAR NMR SPECTROSCOPIC (1H, 13C, 15N, 17O) DATA AND THE RESULTS OF QUANTUM-CHEMICAL CALCULATIONS
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As a result of an analysis of the parameters of the 1H, 13C, 15N, and 17O NMR spectra of a number of N-vinylanilides it was established that the phenyl ring is orthogonal to the plane of the amido group, while the vinyl and carbonyl groups are coplanar.Th
- Afonin, A. V.,Trofimov, B. A.,Malysheva, S. F.,Vashchenko, A. V.
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p. 181 - 190
(2007/10/02)
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- SINGLE-STAGE SYNTHESIS OF 3-ARYLAMINO-1-BUTYNES FROM ANILIDES AND ACETYLENE
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3-Arylamino-1-butynes were obtained with 20-50percent yields by the reaction of anilides and acetylene (130-160 deg C, initial pressure 12 atm) in the presence of the superbasic system formed during the hydrogenolysis of the anilide by metallic potassium in tetrahydrofuran or dioxane.
- Trofimov, B. A.,Malysheva, S. F.,Vyalykh, E. P.
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p. 1405 - 1409
(2007/10/02)
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