Visible‐light‐induced heterogeneous photocatalysis for decarboxylative alkynylation has been performed. The using of cheap, metal‐free and recyclable graphitic carbonnitride (g‐C3N4) as the photoredox catalyst in the process enables the facile transformation of a variety of carboxylic acids into structurally diverse alkyne‐containing molecular architectures under mild and environmentally‐benign conditions
可见光诱导的非均相光催化脱羧炔基反应。使用便宜,无金属且可回收的石墨氮化碳(g ‐ C 3 N 4)作为该过程中的光氧化还原催化剂,可以在温和和环境友好的条件下将多种羧酸轻松转化为结构多样的含炔分子结构。明显地,反应系统的非均质性质允许催化剂在多次运行中的回收和再利用而不损失反应性。光催化反应也可以以连续流动的方式进行并按比例放大至克级。此外,该策略在未活化烯烃的1,2氨基炔基化中的应用进一步凸显了该策略的制备能力。
Metal-Free Electrophilic Alkynylation of Sulfenate Anions with Ethynylbenziodoxolone Reagents
作者:Stephanie G. E. Amos、Stefano Nicolai、Alec Gagnebin、Franck Le Vaillant、Jerome Waser
DOI:10.1021/acs.joc.9b00050
日期:2019.3.15
Alkynyl sulfoxides are important buildingblocks with a unique reactivity in organic chemistry, but only a few reliable methods have been reported to synthesize them. A novel route to access alkynyl sulfoxides is reported herein by using ethynyl benziodoxolone (EBX) reagents to trap sulfenate anions generated in situ, via a retro-Michael reaction. The reaction takes place under metal-free and mild
A general and efficient method for the direct alkynylation of unactivatedC(sp3)-H bondsunder metal-free condition is described. The reaction smoothly performs undermildconditions and shows excellent functional-group tolerance....
A transition-metal-free synthetic method of various ynones via decarboxylative alkynylation of α-keto acids is described. The reaction is carried out undermildconditions and exhibits remarkable tolerance of functional groups. The mechanism of a radical process is proposed in the reaction.
A facile strategy for accessing 3-alkynylchromones through gold-catalyzed alkynylation/cyclization of o-hydroxyarylenaminones
作者:Manjur O. Akram、Saibal Bera、Nitin T. Patil
DOI:10.1039/c6cc07119h
日期:——
A strategy based on tandem alkynylation ofo-hydroxyarylenaminones followed by intramolecular cyclization has been developed to generate a diverse array of 3-alkynyl chromones.