A cinchona alkaloid catalyzed enantioselective sulfa-Michael/aldol cascade reaction of isoindigos: construction of chiral bispirooxindole tetrahydrothiophenes with vicinal quaternary spirocenters
in addition to a small amount of demethoxylated naphthofuran II and benzoindolinone III (Scheme 1, eq. 1). Although the yield of the heterocyclic compounds II and III was poor, the carbon-carbon bond formation efficiently occurred during the reaction. We also reported the facile synthesis of 3,4-dihydro-2(1H)-quinolinones, 540 HETEROCYCLES, Vol. 90, No. 1, 2015
Studies on single-electron transfer reagents. Part IV reaction of nitrogen heterocycles with sodium naphthalenide
作者:Avijit Banerji、Sukla Maiti (née Jana)
DOI:10.1016/s0040-4020(01)85374-6
日期:1994.1
Reactions of several nitrogen heterocycles with sodium naphthalenide in aprotic solvents were investigated. The reactions were quenched with an aqueous buffer. Quinoline reacted by the single-electron transfer pathway to give a ‘dimeric’ (3), a ‘trimeric’ product (4) and 4-quinolone. 4-Quinazolinone afforded a single ‘dimeric’ product (9). Reaction of isoquinoline in monoglyme gave three ‘dimeric’
NaI-mediated divergent synthesis of isatins and isoindigoes: a new protocol enabled by an oxidation relay strategy
作者:Hong-hua Zhang、Yong-qiang Wang、Long-tao Huang、Long-qing Zhu、Yi-yue Feng、Ying-mei Lu、Quan-yi Zhao、Xue-qiang Wang、Zhen Wang
DOI:10.1039/c8cc04471f
日期:——
A new approach for the synthesis of isatins and isoindigoes by an inexpensive and environmentally friendly NaI-mediated transformation is disclosed.
通过一种廉价且环保的NaI介导转化揭示了一种合成异吲哚和异吲哚的新方法。
COS-triggered oxygen/sulfur exchange of isatins: chemoselective synthesis of functionalized isoindigos and spirothiopyrans <i>via</i> self-condensation and the thio-Diels–Alder reaction
作者:Wei Chen、Hui Zhou、Bai-Hao Ren、Wei-Min Ren、Xiao-Bing Lu
DOI:10.1039/d1ob02157e
日期:——
organocatalytic oxygen/sulfur atom exchangereaction (O/S ER) of isatins by employing carbonyl sulfide (COS) as a novel sulfuring reagent under mild reaction conditions. 8-Diazabicyclo[5.4.0]undec-7-ene (DBU) exhibited excellent activity in this approach. Remarkably, the chemical transformations of in situ generated 3-thioisatins can be tuned via the judicious choice of reaction solvents in a one pot
在此,我们采用羰基硫(COS)作为新型硫化试剂,在温和的反应条件下,首次展示了靛红的有机催化氧/硫原子交换反应(O/S ER)。8-Diazabicyclo[5.4.0]undec-7-ene (DBU) 在这种方法中表现出优异的活性。值得注意的是,原位生成的 3-硫代靛红的化学转化可以通过在一锅法中明智地选择反应溶剂来调节,从而能够通过自缩合过程在 CH 3 CN中选择性形成官能化异靛蓝,或者在 DMSO 中选择性形成螺噻喃在共轭二烯存在下,通过硫代-狄尔斯-阿尔德反应。用实验和密度泛函理论方法进行的机理研究表明,靛红和 COS 之间的 O/S ER 导致形成 3-硫代靛红作为关键中间体,其进一步经历溶剂控制的转化,分别生成异靛蓝或螺硫吡喃。易于访问的基板和操作简单性使该过程适合进一步探索。这种转化的实用性通过基于异靛蓝的药物分子和供体-受体共轭聚合物的克级合成得到证明。
Gold(I)-Catalyzed Dimerization of 3-Diazooxindoles towards Isoindigos
作者:Xinbo Yao、Tao Wang、Zunting Zhang
DOI:10.1002/ejoc.201800809
日期:2018.8.31
Isoindigos were prepared via a gold‐catalyzed dimerization of 3‐diazooxindoles. Besides a broad substrate scope and functional group tolerance, the reaction also exhibited high efficiency on a gram‐scale reaction.