An efficient protocol for the Cα-H heteroarylation of ethers, amides, and alcohols using air and light under mild conditions is described. The reaction is applicable to a wide spectrum of functional groups. The generation of C-radicals via photoinduced aerobic oxidation of ethers, amides, and alcohols is the key feature of the process. Control experiments suggest a radical pathway for the reaction
描述了在温和条件下使用空气和光对醚、酰胺和醇进行 Cα - H 杂芳基化的有效方案。该反应适用于广泛的官能团。通过醚、酰胺和醇的光诱导有氧氧化产生 C-自由基是该过程的关键特征。对照实验表明该反应的自由基途径。
Dual C(sp<sup>3</sup>)–H Functionalization of Cyclic Ethers via Singlet Oxygen-Mediated Ring Opening and Ring Closing
A metal-free dual C(sp3)–H bond functionalization of saturated cyclic ethers via photooxidative singlet oxygen-mediated ringopening and ring closing has been developed, providing a method for generating hydrobenzofurans/pyrans/dioxins. Mechanistic studies have confirmed that ring-opening intermediates were effectively generated by singlet oxygen-mediated C(sp3)–H activation and efficiently reacted
A long-range tautomeric effect on a new Schiff isoniazid analogue, evidenced by NMR study and X-ray crystallography
作者:Constantin I. Tănase、Constantin Drăghici、Sergiu Shova、Anamaria Hanganu、Emese Gal、Cristian V. A. Munteanu
DOI:10.1039/c8nj01680a
日期:——
Long-range tautomerism to a N,O-aminal thereby closing a tetrahydrofuran ring was evidenced for an isoniazid analogue, whose accidental synthesis is presented in the paper. The isoniazid analogue was synthesized by the reaction of isoniazid with 2-hydroxy-tetrahydrofuran which was demonstrated to exist in old THF together with other peroxides, especially 2-HOO-THF. The same compound was efficiently
对于异烟肼类似物,证明其长距离互变异构为N,O-氨基,从而闭合四氢呋喃环,在本文中提出了其意外合成。异烟肼类似物是通过异烟肼与2-羟基-四氢呋喃的反应合成的,该反应已证明与其他过氧化物特别是2-HOO-THF一起存在于旧的THF中。通过在异烟肼存在下还原该过氧化物,可从含有2-HOO-THF的THF中有效地获得相同的化合物。还合成了2,4-二硝基苯基hydr。1,4-丁二醇的氧化和所得的单醛与异烟肼的反应得到相同的化合物。DMSO- d 6的NMR光谱证明存在线性互变异构体并且通过X射线分析证实是晶体中的单个互变异构体。在CDCl 3的NMR光谱中发现环状N,O-氨基互变异构体,这是由于分子内HCl催化的羟基向线性互变异构体的双键CH N的加成,从而封闭了四氢呋喃环。根据鲍德温规则(5- exo -trig),这是有利的环化。对于从前列腺素合成中使用的从两种乳糖醇获得的两种异烟肼类似物,也
Aerobic C–H Functionalization Using Pyrenedione as the Photocatalyst
作者:Jie Wu、Dejiang Huang、Yuannian Zhang、Xin Yang
DOI:10.1055/s-0040-1707135
日期:2020.9
disclose a visible-light-promoted aerobic alkylation of activated C(sp3)–H bonds using pyrenedione (PYD) as the photocatalyst. Direct C–H bond alkylation of tetrahydrofuran with alkylidenemalononitriles is accomplished in over 90% yield in the presence of 5 mol% of PYD and 18 W blue LED light under ambient conditions. The substrate scope is extended to ethers, thioethers, and allylic C–H bonds in reactions
Synthesis of Ag/g-C<sub>3</sub>
N<sub>4</sub>
Composite as Highly Efficient Visible-Light Photocatalyst for Oxidative Amidation of Aromatic Aldehydes
作者:Lingling Wang、Min Yu、Chaolong Wu、Nan Deng、Chao Wang、Xiaoquan Yao
DOI:10.1002/adsc.201600138
日期:2016.8.18
resonance (LSPR) effect of Ag NPs exhibited high photocatalytic activities toward aerobic oxidative amidation of aromatic aldehydes under visiblelight irradiation. Good to excellent yields were achieved for various substrates under the light of a 25 W compact fluorescent light (CFL) bulb in air. The operationally easy procedure provides an economical, green, and mild alternative for the formation
在此贡献中,合成了Ag / g-C 3 N 4纳米复合材料,并用作可见光照射下有机反应的高效绿色光催化剂。经过改良的溶剂热焙烧工艺,以三聚氰胺和氰尿酰氯为前体,合成了层状多孔g-C 3 N 4。银纳米颗粒(NPs)可以很好地固定在g-C 3 N 4纳米片上,该片是通过简便的浸渍-焙烧方法制备的。廉价,稳定的g‐C 3 N 4Ag NPs的局部表面等离子体激元共振(LSPR)效应对可见光辐照下芳香醛的需氧氧化酰胺化表现出很高的光催化活性。在空气中使用25 W紧凑型荧光灯(CFL)灯泡的情况下,各种基板的良率都达到了很好的水平。操作简便的程序为形成酰胺键提供了一种经济,绿色和温和的替代方法。