以K 2 S 2 O 8 -氮掺杂石墨烯的混合物为氧化剂,从芳基炔酸酯和亚硝酸盐直接得到一系列高收率的3-nitro-4-aryl-2 H -chromen-2-ones在室温下的含水介质中。还报道了该反应的合理机制。它表明该产物是通过硝基自由基加成、螺环化和酯迁移的级联反应形成的。与合成 3-nitro-4-aryl-2 H的已知方法相比-chromen-2-ones 来自芳基炔酸酯,该协议是环保、可持续、实用和节能的,并且不使用有害的硝基源。此外,这种方法中使用的氮掺杂石墨烯可以很容易地回收和重复使用至少四次而不会失去其活性。
Visible Light-Induced Decarboxylative Acylarylation of Phenyl Propiolates with α-Oxocarboxylic Acids to Coumarins Catalyzed by Hypervalent Iodine Reagents under Transition Metal-Free Conditions
作者:Shuai Yang、Hui Tan、Wangqin Ji、Xiangbiao Zhang、Pinhua Li、Lei Wang
DOI:10.1002/adsc.201600721
日期:2017.2.2
No Abstract
没有摘要
An efficient light on–off one-pot method for the synthesis of 3-styryl coumarins from aryl alkynoates
An efficientone-pot stepwise method to synthesize 3-styryl-4-arylcoumarins from simple alkynoates is demonstrated. On the basis of the control experiments, a possible mechanism involving light-driven radical cyclization and Pd-catalysed cross-coupling processes for this synthesismethod is proposed. The results of X-ray analysis and spectroscopy experiments prove that the substituent effect has a
Visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids to coumarin derivatives under metal-free conditions
作者:Wenchao Yang、Shuai Yang、Pinhua Li、Lei Wang
DOI:10.1039/c5cc00878f
日期:——
A visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids has been developed at room temperature under metal-free conditions.
已在室温下无金属条件下开发了苯基丙炔酸酯与亚砜酸的可见光引发氧化环化反应。
Visible-light photoredox catalyzed cyclization of aryl alkynoates for the synthesis of trifluoromethylated coumarins
作者:Mei-jie Bu、Guo-ping Lu、Chun Cai
DOI:10.1016/j.catcom.2018.06.009
日期:2018.8
for the synthesis of coumarin derivatives via visible-lightphotoredoxcatalysis has been developed using fac-Ir(ppy)3 as the photocatalyst under mild conditions. Trifluoromethanesulfonyl chloride is utilized as the trifluoromethylation reagent, which is cheap and readily available. Aryl alkynoates are trifluoromethylated, then undergo a radical cyclization and a cascade ester migration to generate target
Synthesis of 3-sulfonyl coumarins through radical sulfonylation with disulfides under catalyst-free conditions
作者:Hexiang Ren、Ming Zhang、Ai Qin Zhang
DOI:10.1016/j.tet.2018.07.014
日期:2018.8
strategy for the synthesis of 3-sulfonyl coumarins via ipso-cyclization/1,2-ester migration from substituted phenyl 3-phenylpropiolates with disulfides and potassium persulfate as sulfonylating reagents was developed, halogen and many other electron-withdrawing or -donating functional groups are tolerated. When naphthalen-1-yl 3-phenylpropiolate was used as a starting material, a spiro compound was obtained