A mild one-pot approach to 3-arylacetylene coumarins with potential AIE activities was developed via photosensitizer-free photocatalysis and thermocatalysis.
通过无光敏剂光催化和热催化,开发了一种新型的一锅法合成具有潜在AIE活性的3-芳基乙炔香豆素。
Cyanomethylation and Cyclization of Aryl Alkynoates with Acetonitrile under Transition-Metal-Free Conditions: Synthesis of 3-Cyanomethylated Coumarins
作者:Yulan Yu、Shengyi Zhuang、Ping Liu、Peipei Sun
DOI:10.1021/acs.joc.6b02155
日期:2016.11.18
Cyanomethylated coumarins were synthesized via cyanomethylation and cyclization of aryl alkynoates using cheap and available reagent acetonitrile as the cyanomethyl source in the presence of TBPB (tert-butyl peroxybenzoate) under transition-metal-free conditions. For the substrates with various substituents on benzene ring, the reaction proceeded smoothly to give the corresponding products in moderate
Visible-light-mediated direct difluoromethylation of alkynoates: synthesis of 3-difluoromethylated coumarins
作者:Mei Zhu、Weijun Fu、Zhiqiang Wang、Chen Xu、Baoming Ji
DOI:10.1039/c7ob02366a
日期:——
developed. The well-designed photoredox system induces a single-step, regioselective installation of a CF2H onto alkynes. Difluoromethyl sulfone was used as an easy to handle CF2H radical source to afford the desired 3-difluoromethylated coumarins in moderate to good yields via radical-triggered tandem difluoromethylation/5-exo cyclization/ ester migration process.
Persulfate-nitrogen doped graphene mixture as an oxidant for the synthesis of 3-nitro-4-aryl-2<i>H</i>-chromen-2-ones from aryl alkynoate esters and nitrite
作者:Palani Natarajan、Priya、Deachen Chuskit
DOI:10.1039/d2ob00827k
日期:——
s in good yields have directly been obtained from aryl alkynoate esters and nitrite by employing a mixture of K2S2O8-nitrogen doped graphene as an oxidant in a watery medium at room temperature. A plausible mechanism for the reaction is also reported. It reveals that the product is formed through a cascade of nitroradical addition, spirocyclization, and ester migration. When compared to known methods
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。
GARCIA H.; IBORRA S.; PRIMO J.; MIRANDA M. A., J. ORG. CHEM., 51,(1986) N 23, 4432-4436