A highly efficient and environmentally benign protocol for the synthesis of 2-amino-5,7-dimethoxy-4- aryl/alkyl-4H-chromene-3-carbonitrile derivatives by one-pot three-component coupling reacting of aromatic aldehydes...A highly efficient and environmentally benign protocol for the synthesis of 2-amino-5,7-dimethoxy-4- aryl/alkyl-4H-chromene-3-carbonitrile derivatives by one-pot three-component coupling reacting of aromatic aldehydes, malononitrile and 3,5-dimethoxy phenol under reflux condition has been developed in aqueous EtOH media using Na2O-Al2O3-P2O5 glass-ceramic system.展开更多
The reactive intermediate generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylate was trapped by 6- quinolinol to produce highlyfunctionalized 4H-chromenes in fairly good yields.
An efficient synthesis of functionalized 4H-chromenes by the tandem reaction of β,γ-unsaturated α- ketoesters with 2-naphthols, 1 -naphthols, and 1,3-dihydroxynaphthalenes has been accomplished with high selectivit...An efficient synthesis of functionalized 4H-chromenes by the tandem reaction of β,γ-unsaturated α- ketoesters with 2-naphthols, 1 -naphthols, and 1,3-dihydroxynaphthalenes has been accomplished with high selectivity and excellent yields in the presence of a catalytic amount of bismuth triflate [Bi（OTf）3, 5 mol%] under mild conditions. The functionalized 4H-chromene synthesis and our previous 2H- chromene hemiacetal synthesis could complement each other to enrich reaction diversity.展开更多
A novel organocatalytic cascade process initiated by 1,6-conjugated addition has been successfully developed. A range of pharmaceutically active 2-amino-4-aryl-4H-chromenes were readily obtained in high yields（88%-99...A novel organocatalytic cascade process initiated by 1,6-conjugated addition has been successfully developed. A range of pharmaceutically active 2-amino-4-aryl-4H-chromenes were readily obtained in high yields（88%-99%） and excellent enantiopurities（86%-99% ee）. The functionalized para-Quinone methides（p-OMs） could be facilely obtained.展开更多
A Cu（I）-catalyzed one-pot tandem reaction of 2-bromobenzyl bromides with 1,3-dicarbonyl compounds leading to 4H- chromene derivatives has been developed. This new approach toward 4H-chromenes combines several reacti...A Cu（I）-catalyzed one-pot tandem reaction of 2-bromobenzyl bromides with 1,3-dicarbonyl compounds leading to 4H- chromene derivatives has been developed. This new approach toward 4H-chromenes combines several reactions in one pot and builds molecular complexity from readily available starting materials.展开更多
A simple, efficient, and environmentally benign method for the synthesis of 4H-chromene derivatives was developed using well ordered and recoverable amino functionalized silica gel as a base catalyst. The 4H-chromene ...A simple, efficient, and environmentally benign method for the synthesis of 4H-chromene derivatives was developed using well ordered and recoverable amino functionalized silica gel as a base catalyst. The 4H-chromene derivatives were obtained in short time and excellent yield （87%-96%） by three component reaction of aldehydes, malononitrile and cyclic 1,3-diketones in water at 70 ℃.展开更多
Chromenes represent an important class of six-membered heterocycles and have drawn tremendous attention in recent years. In this article, we report a convenient and practical synthesis of this heterocycle by a silver(...Chromenes represent an important class of six-membered heterocycles and have drawn tremendous attention in recent years. In this article, we report a convenient and practical synthesis of this heterocycle by a silver(I)-catalyzed cycloaddition reaction between in situ generated ortho-quinone methides and N-allenamides. Diverse 4H-chromenes were synthesized in good to excellent yields under very mild conditions.展开更多
An efficient and environmentally benign procedure for the reactions of three components condensation of sali- cylaldehyde and two different CH acids to give 2-amino-4H-chromenes catalyzed by a series of basic-function...An efficient and environmentally benign procedure for the reactions of three components condensation of sali- cylaldehyde and two different CH acids to give 2-amino-4H-chromenes catalyzed by a series of basic-functional- ized ionic liquids was reported. The most possible reaction pathway was proposed for the first time by performing density functional theory （DFT） calculations. Both cation and anion of [Bmim]OH have a cooperative effect on the reaction. [Bmim]＋ increases the electrophilicity of salicylaldehyde via intermolecular hydrogen bonds, while OH deprives proton of two CH acids to strengthen their nucleophilic ability.展开更多
A novel method for the preparation of highly functionalized 4-oxo-3-(1H-pyrrol-3-yl)-4H-chromenes(OPCMs)from 3-formylchromones andα-isocyanoacetates via an unprecedented three-component[1+1+3]cycloaddition reaction i...A novel method for the preparation of highly functionalized 4-oxo-3-(1H-pyrrol-3-yl)-4H-chromenes(OPCMs)from 3-formylchromones andα-isocyanoacetates via an unprecedented three-component[1+1+3]cycloaddition reaction in one pot was developed.The three-component cascade reaction was enabled by refluxing a mixture of the substrates in 1,4-dioxane in the presence of Ag_(2)CO_(3) as a Lewis acid promoter.As a result,a series of functionalized pyrroles(OPCMs,3),was prepared regioselectively and in high yields(80%-88%)through the formation of three bonds.This protocol can be used in the synthesis of OPCMs rather than through conventional,multi-step reactions and is suitable for both combinatorial and parallel syntheses of pyrroles.展开更多
基金the Najafabad Branch,Islamic Azad University for financial support of this research
文摘A highly efficient and environmentally benign protocol for the synthesis of 2-amino-5,7-dimethoxy-4- aryl/alkyl-4H-chromene-3-carbonitrile derivatives by one-pot three-component coupling reacting of aromatic aldehydes, malononitrile and 3,5-dimethoxy phenol under reflux condition has been developed in aqueous EtOH media using Na2O-Al2O3-P2O5 glass-ceramic system.
文摘The reactive intermediate generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylate was trapped by 6- quinolinol to produce highlyfunctionalized 4H-chromenes in fairly good yields.
基金supported by the Science and Technology Development Project of Weihai (Nos.2011DXGJ13,2012DXGJ02)the Natural Science Foundation of Shandong Province (No.ZR2012BM002)the National Natural Science Foundation of China (Nos.21202028,21372054)
文摘An efficient synthesis of functionalized 4H-chromenes by the tandem reaction of β,γ-unsaturated α- ketoesters with 2-naphthols, 1 -naphthols, and 1,3-dihydroxynaphthalenes has been accomplished with high selectivity and excellent yields in the presence of a catalytic amount of bismuth triflate [Bi（OTf）3, 5 mol%] under mild conditions. The functionalized 4H-chromene synthesis and our previous 2H- chromene hemiacetal synthesis could complement each other to enrich reaction diversity.
基金financially supported by the National Natural Science Foundation of China(No.21402163)the Fundamental Research Funds for the Central Universities of Southwest Minzu University (No. 2016NGJPY02)+1 种基金the Graduate Innovation Project of Southwest Minzu University (No. CX2017SZ016)the Undergraduate Innovation Project of Southwest Minzu University (No. S201610656092)
文摘A novel organocatalytic cascade process initiated by 1,6-conjugated addition has been successfully developed. A range of pharmaceutically active 2-amino-4-aryl-4H-chromenes were readily obtained in high yields（88%-99%） and excellent enantiopurities（86%-99% ee）. The functionalized para-Quinone methides（p-OMs） could be facilely obtained.
基金supported by the National Natural Science Foundation of China(Nos20972042 and 21172057)the Opening Foundation of Zhejiang Provincial Top Key Discipline
文摘A Cu（I）-catalyzed one-pot tandem reaction of 2-bromobenzyl bromides with 1,3-dicarbonyl compounds leading to 4H- chromene derivatives has been developed. This new approach toward 4H-chromenes combines several reactions in one pot and builds molecular complexity from readily available starting materials.
文摘A simple, efficient, and environmentally benign method for the synthesis of 4H-chromene derivatives was developed using well ordered and recoverable amino functionalized silica gel as a base catalyst. The 4H-chromene derivatives were obtained in short time and excellent yield （87%-96%） by three component reaction of aldehydes, malononitrile and cyclic 1,3-diketones in water at 70 ℃.
基金supported by the National Natural Science Foundation of China(21572118,21750110444)the Natural Science Foundation of Shandong Province(ZR2018MB010)+1 种基金subject construction funds(104.205.2.5)Tang scholar award of Shandong University
文摘Chromenes represent an important class of six-membered heterocycles and have drawn tremendous attention in recent years. In this article, we report a convenient and practical synthesis of this heterocycle by a silver(I)-catalyzed cycloaddition reaction between in situ generated ortho-quinone methides and N-allenamides. Diverse 4H-chromenes were synthesized in good to excellent yields under very mild conditions.
文摘An efficient and environmentally benign procedure for the reactions of three components condensation of sali- cylaldehyde and two different CH acids to give 2-amino-4H-chromenes catalyzed by a series of basic-functional- ized ionic liquids was reported. The most possible reaction pathway was proposed for the first time by performing density functional theory （DFT） calculations. Both cation and anion of [Bmim]OH have a cooperative effect on the reaction. [Bmim]＋ increases the electrophilicity of salicylaldehyde via intermolecular hydrogen bonds, while OH deprives proton of two CH acids to strengthen their nucleophilic ability.
基金the Natural Science Foundation of Yunnan Province(No.2019FY003003)the National Natural Science Foundation of China(No.21662042)the Scientific and Technological Innovation Team of Green Synthesis and Activity Research of Natural-like Heterocyclic Compound Libraries in Universities of Yunnan Province(No.C17624011121).
文摘A novel method for the preparation of highly functionalized 4-oxo-3-(1H-pyrrol-3-yl)-4H-chromenes(OPCMs)from 3-formylchromones andα-isocyanoacetates via an unprecedented three-component[1+1+3]cycloaddition reaction in one pot was developed.The three-component cascade reaction was enabled by refluxing a mixture of the substrates in 1,4-dioxane in the presence of Ag_(2)CO_(3) as a Lewis acid promoter.As a result,a series of functionalized pyrroles(OPCMs,3),was prepared regioselectively and in high yields(80%-88%)through the formation of three bonds.This protocol can be used in the synthesis of OPCMs rather than through conventional,multi-step reactions and is suitable for both combinatorial and parallel syntheses of pyrroles.
