N‐Ethynylation of Anilides Decreases the Double‐Bond Character of Amide Bond while Retaining
<i>trans</i>
‐Conformation and Planarity
作者:Ryu Yamasaki、Kento Morita、Hiromi Iizumi、Ai Ito、Kazuo Fukuda、Iwao Okamoto
DOI:10.1002/chem.201901451
日期:2019.8
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
活化的酰胺键引起了广泛的关注。然而,大多数研究的部分具有扭曲的酰胺特性。为了增加激活酰胺键并保持其平面性的新策略,我们设想在酰胺氮上引入炔基,以通过n N→C sp的结合破坏酰胺共振。在这种情况下,通过DFT计算,晶体学和NMR光谱分析研究了N-乙炔基取代的芳族酰胺的构象和性质。与N-乙基和乙烯基取代的乙酰苯胺的顺式构象偏爱相反,N-乙炔基取代的乙酰苯胺更倾向于反式晶体和溶液中的构象。它还具有降低的C(O)-N键双键特性,而不会发生酰胺扭曲。N-乙炔基取代的乙酰苯胺进行选择性的C(O)-N键或N-C(sp)键裂解反应,并作为偶联反应或易于裂解的系链的活化酰胺,具有潜在的应用前景。