FeCl3·6H2O-catalyzed facile and efficient synthesis of pyrano[4,3-b]quinolines and isochromenes
作者:Mrityunjaya Asthana、Jay Bahadur Singh、Radhey M. Singh
DOI:10.1016/j.tetlet.2015.12.102
日期:2016.2
developed for the synthesis of 1,3-disubstituted 1H-pyrano[4,3-b]quinolines from o-arylethnylquinonylmethanol via 6-endo-dig cyclization of alcoholic –OH onto alkynes in good to excellent yields. The reaction conditions were successfully exploited on primary and tertiary alcohol analogs. The reagent was further generalized with the aromatic alcohol analogs providing the synthesis of isochromenes in
廉价的1摩尔%的FeCl 3 ·6H 2 ö试剂已经被用于合成开发1,3-二取代1 ħ吡喃并[4,3- b ]喹啉由ö经由6 -arylethnylquinonylmethanol -内将醇-OH环化成良好至优异收率的炔烃。反应条件已成功地用于伯醇和叔醇类似物。该试剂进一步用芳族醇类似物泛化,从而以高收率合成了异色烯。从伯醇到仲醇到叔醇的反应速率和产率的提高可以归因于烷基的诱导作用,其增强了羟基的亲核性并加速了环化模式。
Base-free NIS promoted electrophilic cyclization of alkynes: an efficient synthesis of iodo substituted pyrano[4,3-b]quinolines
作者:Bhawana Singh、Atish Chandra、Seema Singh、Radhey M. Singh
DOI:10.1016/j.tet.2010.10.081
日期:2011.1
A simple and mild procedure for the synthesis of iodo substituted 1H-pyrano[4,3-b]quinolines has been achieved using NIS reagent in the absence of base from 2-alkynylquinoline-3-carboxaldehydes via intramolecular electrophiliccyclization onto alkynes in good to excellent yields in a short duration of time. The reactions proceeded smoothly in a normal solvent in aerobic atmosphere at room temperature
在没有碱的情况下,使用NIS试剂通过分子内亲电环化到炔烃上,从2-炔基喹啉3-羧醛中制得了一种简单,温和的合成碘代1 H-吡喃并[4,3- b ]喹啉的简单方法在短时间内获得出色的产量。反应在室温下于普通溶剂中在有氧气氛中顺利进行。喹啉或炔基部分上取代基的存在对环化反应速率没有影响。还讨论了钯催化的碘基向C–C键的转化。
Chemoselective Azidation of <i>o</i>-Alkynylaldehydes over [3 + 2] Cycloaddition and Subsequent Staudinger Reaction: Access to Benzonaphthyridines/Naphthyridines
作者:Pradeep Kumar、Trapti Aggarwal、Akhilesh K. Verma
DOI:10.1021/acs.joc.7b01016
日期:2017.6.16
conditions is described. Mechanisticstudies confirm the formation of azido-pyranoquinolines through nucleophilic attack of azide on pyrilium intermediate over [3 + 2] cycloaddition of the azide on the alkyne. The synthesized azido-pyranoquinolines were transformed into benzonaphthyridines via Staudinger reaction. The mechanistic pathway was supported by deuterium labeling experiment and X-ray crystallographic
Radical Promoted Synthesis of Furoquinolines
<i>via</i>
Anomalous Dakin‐Type Reaction
作者:Sushmita、Trapti Aggarwal、Kapil Mohan Saini、Akhilesh K. Verma
DOI:10.1002/adsc.202100674
日期:2021.10.5
approach for the selectivesynthesis of furo[3,2-b]quinolines and benzylidene-1,3-dihydrofuro[3,4-b]quinolines have been achieved from 2-alkynyl quinoline-3-carbaldehydes by fine-tuning of base and oxidant in good yields. In the presence of an oxidant, the reaction afforded the 5-endo-dig cyclized furoquinolines by decarbonylative intramolecular cyclizationvia a Dakin-type reaction; however, in the
通过微调从 2-炔基喹啉-3-甲醛中实现了选择性合成呋喃[3,2- b ]喹啉和亚苄基-1,3-二氢呋喃[3,4- b ]喹啉的自由基促进方法碱和氧化剂的高产率。在氧化剂的存在下,该反应通过Dakin 型反应通过脱羰分子内环化得到 5-endo-dig 环化呋喃喹啉;然而,在没有氧化剂的情况下,通过还原性分子内环化选择性地获得了 5-exo-dig 环化产物。X 射线晶体学研究进一步支持呋喃喹啉的形成。所提出的机制得到了控制实验的良好支持。
Unveiling the Three-Component Phosphonylation on Alkynylaldehydes: Toolbox toward Fluorescent Molecules
作者:Deepika Thakur、Trapti Aggarwal、Muskan、Sushmita、Akhilesh K. Verma
DOI:10.1021/acs.joc.2c02915
日期:2023.2.17
A regioselective tandem approach for annulated napthyridines/isoquinolines embedded with the phosphine oxide group under mild reaction conditions has been achieved in good to excellent yields. The designed strategy involves the triflate-induced formation of new C sp3–P and C sp2–N bondformation in one pot. This protocol was also well tolerated for the construction of densely functionalized organo-phosphorylated
在温和的反应条件下,已经实现了一种区域选择性串联方法,用于嵌入氧化膦基团的环状萘啶/异喹啉,收率良好。设计的策略涉及三氟甲磺酸诱导在一个锅中形成新的 C sp 3 -P 和 C sp 2 -N 键。该协议对于以良好的产量构建密集功能化的有机磷酸化色烯也具有很好的耐受性。此外,膦衍生的磺胺二甲嘧啶和磺胺甲恶唑药物也以良好的收率成功合成。机理研究表明,离子通路和区域选择性6-内切酶的形成通过 X 射线晶体学研究证实了环化产物。有趣的是,选择性化合物的光物理研究揭示了它们的激发荧光特性。