Hypoiodite-catalysed oxidative cyclisation of Michael adducts of chalcones with 1,3-dicarbonyl compounds: a facile and versatile approach to substituted furans and cyclopropanes
Through hypoiodite catalysis, the oxidative cyclisation of Michael adducts of chalcones with 1,3-dicarbonyl compounds for divergent synthesis of either furans or cyclopropanes is developed. The selective synthesis of major products...
A simple and atom-economic synthesis of highly substituted thiophenes is demonstrated. Heating a solution of a chalcone and a linear/cyclic 1,3-dicarbonyl compound with elemental sulfur in CH3CN in the presence of NEt3 at 80 °C afforded the corresponding substituted thiophenes in good to excellent yields.
Bi(OTf)3-catalyzed solvent-free synthesis of pyrano[3,2-c]coumarins through a tandem addition/annulation reaction between chalcones and 4-hydroxycoumarins
作者:Mukut Gohain、Johannes H. van Tonder、Barend C.B. Bezuidenhoudt
DOI:10.1016/j.tetlet.2013.05.008
日期:2013.7
A Bi(OTf)3-catalyzedtandemaddition/annulation reaction is described in order to synthesize pyrano[3,2-c]coumarins under solvent-free conditions. Substituted/unsubstituted chalcones were conveniently condensed with various 4-hydroxycoumarins by means of this environmentally benign method which produces water as the only side product.
描述了Bi(OTf)3催化的串联加成/环合反应,以便在无溶剂条件下合成吡喃并[3,2- c ]香豆素。借助于这种环境友好的方法,取代的/未取代的查耳酮方便地与各种4-羟基香豆素缩合,该方法产生水作为唯一的副产物。
Erythrosine B Catalyzed Synthesis of trans-Dihydro-4H-furo[3,2-c]chromen-4-ones through Photocatalytic Dehydrogenative sp
3 C–O Bond Formation
A simple and efficient visible-light-induced methodology has been developed for the selective synthesis of dihydro-4H-furo[3,2-c]chromen-4-one derivatives via dehydrogenative coupling reaction. The methodology is highly useful for the synthesis of varieties of dihydro-4H-furo[3,2-c]chromen-4-ones from readily accessible reactants under oxygen atmosphere. Importantly, the additive-free approach has
开发了一种简单有效的可见光诱导方法,用于通过脱氢偶联反应选择性合成 dihydro-4 H -furo[3,2- c ]chromen-4-one 衍生物。该方法对于在氧气气氛下从容易获得的反应物合成各种二氢-4 H-呋喃[3,2- c ]chromen-4-ones 非常有用。重要的是,这种转变也证明了无添加剂的方法。机理研究的结果表明,这种脱氢反应是通过自由基途径进行的。此外,合成的 dihydro-4 H -furo[3,2- c ]chromen-4-one 已转化为不同的 4 H-furo[3,2- c ]chromen-4-ones 通过简单的协议。
Direct synthesis of alkylated 4-hydroxycoumarin derivatives <i>via</i> a cascade Cu-catalyzed dehydrogenation/conjugate addition sequence
作者:Zhiliang Chen、Hongyi Li、Yanjing Liao、Mengqi Wang、Weiping Su
DOI:10.1039/d3cc01960h
日期:——
An efficient approach for the direct synthesis of alkylated 4-hydroxycoumarin derivatives via a Cu-catalyzed cascade dehydrogenation/conjugate addition sequence starting from simple saturatedketones and 4-hydroxycoumarins has been developed. This protocol features excellent functional-group tolerance, easy scale-up, and a broad substrate scope including bioactive molecules. More importantly, a series