An efficient and versatile tandem process of acetalization and cycloisomerization reactions has been developed for the reactions of 1-alkynyl-2-carbonylquinoline substrates. The reaction occurs thanks to Au(I) and Ag(I) catalysis. Silver(I) catalysis has been extensively studied (11 different silver species) on a broad range of quinoline derivatives (variation of alkyne substituent, of carbonyl function
α-pyrone derivatives via the formation of two C–O bonds. In this project, K2S2O8 has been introduced as an efficient oxygen source and C–H functionalization agent in regioselective oxidative cyclizationreaction with a relatively broad substrate scope.
开发了一种新颖且有效的烯醛无金属 C-H 官能化方法,通过形成两个 C-O 键来合成α-吡喃酮衍生物。在该项目中,K 2 S 2 O 8被引入作为区域选择性氧化环化反应中的有效氧源和C-H官能化剂,具有相对广泛的底物范围。
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。
Na2S·9H2O mediated facile synthesis of 1,3-dihydrofuro[3,4-b]quinoline derivatives via domino reduction approach
作者:Rashmi Singh、Tanu Gupta、Vishal Prasad Sharma、Radhey M. Singh、Ashish Kumar Tewari
DOI:10.1016/j.tet.2021.132447
日期:2021.10
A simple, highly efficient method for synthesis of 1,3-dihydrofuro[3,4-b]quinoline is described by the reaction of o-arylalkynyl quinoline aldehydes with Na2S·9H2O via domino reduction approach. The method is simple and proceeds under mild condition under an air atmosphere to give 1,3-dihydrofuro[3,4-b]quinoline in good to excellent yields. The beauty of the reaction is cyclization as well as reduction
邻芳炔基喹啉醛与Na 2 S·9H 2 O通过多米诺还原法反应,描述了一种简单、高效的合成1,3-二氢呋喃[3,4- b ]喹啉的方法。该方法简单,在温和条件下,在空气气氛下进行,以良好至极好的收率得到1,3-二氢呋喃[3,4- b ]喹啉。该反应的美妙之处在于在同一个反应釜中进行了环化和还原。在相同的反应条件下也讨论了醛向伯醇的转化。
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。