Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as ...Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.展开更多
The mass spectrometric fragmentation of 2a,4-disubstituted 5-benzoyl-2a,3,4,5-tetrahydro-2-phenoxy-azeto{[1,2-a]}[1,5]benzodiazepin-1(2H)-ones has been investigated by means of mass-analyzed ion kinetic energy spectro...The mass spectrometric fragmentation of 2a,4-disubstituted 5-benzoyl-2a,3,4,5-tetrahydro-2-phenoxy-azeto{[1,2-a]}[1,5]benzodiazepin-1(2H)-ones has been investigated by means of mass-analyzed ion kinetic energy spectrometry under electron impact ionization conditions. All compounds tend to lose different moieties, such as phenoxy, phenoxy and H, and phenoxyketene. Both [M +-PhO] and [M +-PhOH] ions could further lose CO, and the [M +-PhOCHCO] ions could lose propene or styrene, PhCON, PhCOHN, and other fragments.展开更多
4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amou...4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amount of HPMoOunder solvent-free conditions.展开更多
A novel and sustainable visible-light-enabled multicomponent reaction involving quinoxalin-2(1H)-ones,indoles,and CF3SO2Na that does not require an external photocatalyst is described.This photoinduced reaction employ...A novel and sustainable visible-light-enabled multicomponent reaction involving quinoxalin-2(1H)-ones,indoles,and CF3SO2Na that does not require an external photocatalyst is described.This photoinduced reaction employs air as the sole oxidant,thereby providing a green and highly step-efficient approach to a series of biologically important trifluoromethylated 3-indolequinoxalin-2(1H)-ones.展开更多
The synthesis of 3-(2'-hydroxybutyl)isobenzofuran-1(3H)-onel from phthalicanhydride via the intermediate 3-(2'-oxoethyl) isobenzofuran-1(3H)-one 6 was described.
On the basis of the interesting structures and biological activities exhibited by several heterocyclic systems possessing the pyridone nucleus such as mappcine and camptothecin, we have planed to design the synthesis,...On the basis of the interesting structures and biological activities exhibited by several heterocyclic systems possessing the pyridone nucleus such as mappcine and camptothecin, we have planed to design the synthesis, crystal studies and antibacterial activity of the new 1-((2- chloroquinolin-3yl)-methyl)-pyridine-2(1H)-one building block. An X-ray analysis has provided valuable insight into the effect of steric factors on the three-dimensional shape of this compound which serves as a useful advanced intermediate in the synthesis of these biologically active molecules. A multistep synthesis of camptothecin (5) has been designed by retrosynthetic analysis as part of an ongoing program on lead anticancer drug.展开更多
The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-cr...The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5)A,β = 99.364(2) °,V = 4332.58(18) A^3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm^-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I 〉 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.展开更多
A visible-light-promoted formal[2+2+1]cyclization of N-aryl glycines with quinoxalin-2(1H)-ones to synthesize tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones have been developed.The protocol features operational simplic...A visible-light-promoted formal[2+2+1]cyclization of N-aryl glycines with quinoxalin-2(1H)-ones to synthesize tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones have been developed.The protocol features operational simplicity,mild reaction conditions with blue LED light employing Ru(bpy)3Cl2.6H2O as a photoredox catalyst,a combination of O2 from air and Cu(OAc)2 as the oxidant and broad substrate applicability.展开更多
A new quinazolinone compound 2,3-dihydro-2-(2-hydroxyphenyl)-3-phenyl- quinazolin-4(1H)-one 3 ([C20H16O2N2]?C2H5OH, Mr = 362.42) and compound 2-(2-hydroxy- benzylidene-amino)-N-phenyl-benzamide 2 (C20H16O2N2, Mr = 316...A new quinazolinone compound 2,3-dihydro-2-(2-hydroxyphenyl)-3-phenyl- quinazolin-4(1H)-one 3 ([C20H16O2N2]?C2H5OH, Mr = 362.42) and compound 2-(2-hydroxy- benzylidene-amino)-N-phenyl-benzamide 2 (C20H16O2N2, Mr = 316.34) were prepared from a precursor of 2-amino-N-phenyl-benzamide 1 (C13H12ON2, Mr = 212.25). Compound 3 was characterized by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic, space group Pbca with a = 1.2889(11), b = 1.6170(14), c = 1.7729(15) nm, V = 3.695(6) nm3, Z = 8, F(000) = 1536, Mr = 362.42, Dc = 1.303 g/cm3, μ(MoKα) = 0.087 mm-1, R = 0.0447 and wR = 0.0879. The crystal structure analysis indicates that the title compound has a two-dimensional network structure formed by hydrogen bonds and electrostatic interactions.展开更多
A new monomer of 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] was synthesized from biphenyl and phthalic anhydride, and a novel copoly(aryl ether ketone) (PPEK) was synthesized from 2, 2-bis(4-hydroxyphenyl)-propane (BPA...A new monomer of 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] was synthesized from biphenyl and phthalic anhydride, and a novel copoly(aryl ether ketone) (PPEK) was synthesized from 2, 2-bis(4-hydroxyphenyl)-propane (BPA), 4, 4'-biphenyl-bis-[4-phthalazin-1(2H)-one], 4, 4- difluorodiphenylketone (DFK). The monomer and copolymer were characterized by FT-IR and 1H-NMR. DSC and TGA were used to the novel polymer.展开更多
The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray d...The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562(15), b = 18.118(3), c = 14.055(2)A, β = 99.855(3)^o, V= 2221.9(6)A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F(000) = 1024, R = 0.0607 and wR = 0.1371.展开更多
The title compound (Z)-1-(3-fluorobenzyl)-5-((3-fluorobenzylimino)(2-hydroxy-4- methoxyphenyl)methyl)pyridin-2(1H)-one (C27H22F2N2O3,Mr = 460.47) was synthesized and crystallized. The crystal belongs to ...The title compound (Z)-1-(3-fluorobenzyl)-5-((3-fluorobenzylimino)(2-hydroxy-4- methoxyphenyl)methyl)pyridin-2(1H)-one (C27H22F2N2O3,Mr = 460.47) was synthesized and crystallized. The crystal belongs to the triclinic system,space group P1 with a = 9.951(6),b = 10.059(6),c = 12.927(7)A,α = 109.828(7),β = 102.304(7),γ = 104.898(7)°,Z = 2,V = 1110.2(11)A^3,Dc =1.377 Mg/m^3,μ(MoKα) = 0.102 mm^-1,F(000) = 480,the final R = 0.0449 and Rw = 0.1250 for 4595 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that both m-fluorobenzyl groups are diorientationally disordered because of the rotation of C–C single bond which was represented as F(1),F(2) and F(1'),F(2'). The diorientational disorder was refined and gave the occupancies of 0.665(4) and 0.335(4) for F(1) and F(1'),0.631(3) and 0.369(3) for F(2) and F(2'). Hydrogen bonds existing in the cell link different components to stabilize the crystal structure. The active data proved that the title compound has good anti-HBV activity.展开更多
Using visible light as energy to form free radicals has important synthetic value.A novel and efficient visible-lightmediated strategy has been developed for the generation of thiobenzene radicals through cerium-catal...Using visible light as energy to form free radicals has important synthetic value.A novel and efficient visible-lightmediated strategy has been developed for the generation of thiobenzene radicals through cerium-catalyzed activation of the disulfides.Through this photochemical reaction,various 3-sulfenylated quinoxalin-2(1H)-ones can be conveniently obtained in good yields with good functional group tolerance.Our transformation provides an alternative that allows rapid access to various C3 sulfenylated quinoxalin-2(1H)-ones in a sustainable and practical manner.展开更多
A novel protocol was developed for the construction of highly functionalized pyridin-2(1H)-ones from 3-formylchromones,ethyl 2-(pyridin-2-yl)acetate derivatives and amines via a complex multicomponent cascade reaction...A novel protocol was developed for the construction of highly functionalized pyridin-2(1H)-ones from 3-formylchromones,ethyl 2-(pyridin-2-yl)acetate derivatives and amines via a complex multicomponent cascade reaction involving targeted duplicated ring-opening and duplicated cyclization reactions which form skeleton-reorganized target compounds.A series of pyridin-2(1H)-ones were produced by this reaction accompanied by the formation of three bonds(one C–N and two C–C bonds)and the cleavage of one bond in one step.This protocol can be used in combinatorial and parallel syntheses of various pyridin-2(1H)-ones with potent biological activity.The advantages of this approach include simple and practical operation(multicomponent one-pot),high yields(up to 91%),and products with potential biological activity.展开更多
A facile and metal-free visible-light-enabled three-component reaction of quinoxalin-2(1 H)-ones,alkenes and CF_(3)SO_(2)Na has been developed under air at room temperature.This photocatalytic tandem reaction using 4 ...A facile and metal-free visible-light-enabled three-component reaction of quinoxalin-2(1 H)-ones,alkenes and CF_(3)SO_(2)Na has been developed under air at room temperature.This photocatalytic tandem reaction using 4 CzIPN as the photocatalyst and air as the green oxidant,provides a mild and environmentally friendly approach to access a series of 3-trifluoroalkylated quinoxalin-2(1 H)-ones.展开更多
Quinoxaline-3-carboxylates and analogues are prevalent key structural motifs in bioactive natural products and synthetic drugs.However, the practical protocol for preparation of these motifs from simple raw materials ...Quinoxaline-3-carboxylates and analogues are prevalent key structural motifs in bioactive natural products and synthetic drugs.However, the practical protocol for preparation of these motifs from simple raw materials under mild conditions remains rare. In this article, we report a facile protocol for the efficient preparation of various quinoxaline-3-carbonyl compounds(30 examples,63%–92%) through oxidation coupling of quinoxalin-2(1H)-ones with readily available carbazates(or acyl hydrazines) in the presence of K_2S_2O_8 as an oxidant in metal-and base-free conditions. When tert-butyl carbazate was used as the coupling reagent,the decarboxylation product 3-(tert-butyl)-1-methylquinoxalin-2(1H)-one was obtained. The application of this process into a gram-scale synthesis can be easily accomplished. Mechanistic investigations reveal that the functionalization of quinoxalin-2(1H)-ones via a free-radical pathway.展开更多
Herein,we report a practical electro-reductive protocol for the direct C-H cyanoalkylation of quinoxalin-2(1 H)-ones via iminyl radical-mediated ring opening.These mild reactions proceed under metal-,reductant-,and re...Herein,we report a practical electro-reductive protocol for the direct C-H cyanoalkylation of quinoxalin-2(1 H)-ones via iminyl radical-mediated ring opening.These mild reactions proceed under metal-,reductant-,and reagent-free conditions to provide synthetically useful cyanoalkylated quinoxalin-2(1 H)-ones.展开更多
A visible-light-induced tandem radical intramolecular cyclization/arylatiion of quinoxalin-2(1H)-ones with bromodifluoroacetamides is described.This protocol allows efficient access to a variety of valuableα,α-diflu...A visible-light-induced tandem radical intramolecular cyclization/arylatiion of quinoxalin-2(1H)-ones with bromodifluoroacetamides is described.This protocol allows efficient access to a variety of valuableα,α-difluoro-y-lactam-fused quinoxalin-2(1H)-ones in moder-ate to good yields under metal-free,mild and redox neutral reaction conditions.This strategy is tolerant of various functional groups and a broad range of substrates.The mechanism experiments suggested an involvement of 5-exo-trig cyclization and a radical pro-cess in this transformation.展开更多
A mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employ...A mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employing 4Cz IPN as the metal-free photocatalyst and dioxygen(air) as the environmentally benign oxidant. A number of sulfonated quinoxalin-2(1H)-ones were obtained in satisfactory yields with favorable functional group tolerance. Radical trapping experiment and fluorescence quenching experiments were performed to elucidate this visible-light mediated radical reaction process.展开更多
文摘Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.
文摘The mass spectrometric fragmentation of 2a,4-disubstituted 5-benzoyl-2a,3,4,5-tetrahydro-2-phenoxy-azeto{[1,2-a]}[1,5]benzodiazepin-1(2H)-ones has been investigated by means of mass-analyzed ion kinetic energy spectrometry under electron impact ionization conditions. All compounds tend to lose different moieties, such as phenoxy, phenoxy and H, and phenoxyketene. Both [M +-PhO] and [M +-PhOH] ions could further lose CO, and the [M +-PhOCHCO] ions could lose propene or styrene, PhCON, PhCOHN, and other fragments.
基金Islamic Azad University of Khorram Abad Council for the financial support
文摘4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amount of HPMoOunder solvent-free conditions.
基金This work was supported by Basic Scientific Research Special Funds(No.2020XZ011)Zhejiang Shuren University,the"Ten-thousand Talents Plan"of Zhejiang Province(No.2019R51012)+1 种基金the Technology Research and Development Program of Hangzhou(No.20191203B28)the National Natural Science Foundation of China(No.21302171).
文摘A novel and sustainable visible-light-enabled multicomponent reaction involving quinoxalin-2(1H)-ones,indoles,and CF3SO2Na that does not require an external photocatalyst is described.This photoinduced reaction employs air as the sole oxidant,thereby providing a green and highly step-efficient approach to a series of biologically important trifluoromethylated 3-indolequinoxalin-2(1H)-ones.
文摘The synthesis of 3-(2'-hydroxybutyl)isobenzofuran-1(3H)-onel from phthalicanhydride via the intermediate 3-(2'-oxoethyl) isobenzofuran-1(3H)-one 6 was described.
基金supported by the Department of Science & Technology Government of India (No. SR/FTP/CS-99/2006)
文摘On the basis of the interesting structures and biological activities exhibited by several heterocyclic systems possessing the pyridone nucleus such as mappcine and camptothecin, we have planed to design the synthesis, crystal studies and antibacterial activity of the new 1-((2- chloroquinolin-3yl)-methyl)-pyridine-2(1H)-one building block. An X-ray analysis has provided valuable insight into the effect of steric factors on the three-dimensional shape of this compound which serves as a useful advanced intermediate in the synthesis of these biologically active molecules. A multistep synthesis of camptothecin (5) has been designed by retrosynthetic analysis as part of an ongoing program on lead anticancer drug.
基金Supported by the Natural Science Foundation of Hubei Province (2006ABB016)Key Science Research Project of Hubei Provincial Department of Education (No.D200724001)the Science Research Project of Yunyang Medical College (No.2008CXG01)
文摘The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5)A,β = 99.364(2) °,V = 4332.58(18) A^3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm^-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I 〉 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.
基金We acknowledge partial financial support from the Ministry of Science and Technology of China(No.2016YFE0132600)Henan Center for Outstanding Overseas Scientists(No.GZS2020001)and Zhengzhou University。
文摘A visible-light-promoted formal[2+2+1]cyclization of N-aryl glycines with quinoxalin-2(1H)-ones to synthesize tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones have been developed.The protocol features operational simplicity,mild reaction conditions with blue LED light employing Ru(bpy)3Cl2.6H2O as a photoredox catalyst,a combination of O2 from air and Cu(OAc)2 as the oxidant and broad substrate applicability.
基金This project was supported by the NNSFC (No. 20371039), National Basic Research Program of China (the 973 Program, No. 2003CB214606), and the Key Laboratory Research and Establishment Program and NSF of Department of Education of Shaanxi Province (No. 03JS006 and No. 04JK143)
文摘A new quinazolinone compound 2,3-dihydro-2-(2-hydroxyphenyl)-3-phenyl- quinazolin-4(1H)-one 3 ([C20H16O2N2]?C2H5OH, Mr = 362.42) and compound 2-(2-hydroxy- benzylidene-amino)-N-phenyl-benzamide 2 (C20H16O2N2, Mr = 316.34) were prepared from a precursor of 2-amino-N-phenyl-benzamide 1 (C13H12ON2, Mr = 212.25). Compound 3 was characterized by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic, space group Pbca with a = 1.2889(11), b = 1.6170(14), c = 1.7729(15) nm, V = 3.695(6) nm3, Z = 8, F(000) = 1536, Mr = 362.42, Dc = 1.303 g/cm3, μ(MoKα) = 0.087 mm-1, R = 0.0447 and wR = 0.0879. The crystal structure analysis indicates that the title compound has a two-dimensional network structure formed by hydrogen bonds and electrostatic interactions.
基金This work is sponsored by the National Natural Science Foundation of China (No. 59473901).
文摘A new monomer of 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] was synthesized from biphenyl and phthalic anhydride, and a novel copoly(aryl ether ketone) (PPEK) was synthesized from 2, 2-bis(4-hydroxyphenyl)-propane (BPA), 4, 4'-biphenyl-bis-[4-phthalazin-1(2H)-one], 4, 4- difluorodiphenylketone (DFK). The monomer and copolymer were characterized by FT-IR and 1H-NMR. DSC and TGA were used to the novel polymer.
基金This work was supported by the National Natural Science Foundation of China (No. 20472072 and 20332060)the CAS Academician Foundation of Zhejiang Province
文摘The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562(15), b = 18.118(3), c = 14.055(2)A, β = 99.855(3)^o, V= 2221.9(6)A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F(000) = 1024, R = 0.0607 and wR = 0.1371.
文摘The title compound (Z)-1-(3-fluorobenzyl)-5-((3-fluorobenzylimino)(2-hydroxy-4- methoxyphenyl)methyl)pyridin-2(1H)-one (C27H22F2N2O3,Mr = 460.47) was synthesized and crystallized. The crystal belongs to the triclinic system,space group P1 with a = 9.951(6),b = 10.059(6),c = 12.927(7)A,α = 109.828(7),β = 102.304(7),γ = 104.898(7)°,Z = 2,V = 1110.2(11)A^3,Dc =1.377 Mg/m^3,μ(MoKα) = 0.102 mm^-1,F(000) = 480,the final R = 0.0449 and Rw = 0.1250 for 4595 observed reflections (I 〉 2σ(I)). X-ray analysis reveals that both m-fluorobenzyl groups are diorientationally disordered because of the rotation of C–C single bond which was represented as F(1),F(2) and F(1'),F(2'). The diorientational disorder was refined and gave the occupancies of 0.665(4) and 0.335(4) for F(1) and F(1'),0.631(3) and 0.369(3) for F(2) and F(2'). Hydrogen bonds existing in the cell link different components to stabilize the crystal structure. The active data proved that the title compound has good anti-HBV activity.
基金supported by the National Natural Science Foundation of China(No.21302171)the Zhejiang Shuren University Basic Scientific Research Special Funds,the“Ten-thousand Talents Plan”of Zhejiang Province(No.2019R51012).
文摘Using visible light as energy to form free radicals has important synthetic value.A novel and efficient visible-lightmediated strategy has been developed for the generation of thiobenzene radicals through cerium-catalyzed activation of the disulfides.Through this photochemical reaction,various 3-sulfenylated quinoxalin-2(1H)-ones can be conveniently obtained in good yields with good functional group tolerance.Our transformation provides an alternative that allows rapid access to various C3 sulfenylated quinoxalin-2(1H)-ones in a sustainable and practical manner.
基金support from 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 protocol was developed for the construction of highly functionalized pyridin-2(1H)-ones from 3-formylchromones,ethyl 2-(pyridin-2-yl)acetate derivatives and amines via a complex multicomponent cascade reaction involving targeted duplicated ring-opening and duplicated cyclization reactions which form skeleton-reorganized target compounds.A series of pyridin-2(1H)-ones were produced by this reaction accompanied by the formation of three bonds(one C–N and two C–C bonds)and the cleavage of one bond in one step.This protocol can be used in combinatorial and parallel syntheses of various pyridin-2(1H)-ones with potent biological activity.The advantages of this approach include simple and practical operation(multicomponent one-pot),high yields(up to 91%),and products with potential biological activity.
基金supported by Youth Innovation and Technology Project of Shandong Province(No.2019KJC021)the International Cooperation Project of Qinghai Province(No.2018-HZ-815)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2018MB009)the Qinghai key laboratory of Tibetan medicine research(No.2017-ZJ-Y11)CAS“Light of West China”Program 2018。
文摘A facile and metal-free visible-light-enabled three-component reaction of quinoxalin-2(1 H)-ones,alkenes and CF_(3)SO_(2)Na has been developed under air at room temperature.This photocatalytic tandem reaction using 4 CzIPN as the photocatalyst and air as the green oxidant,provides a mild and environmentally friendly approach to access a series of 3-trifluoroalkylated quinoxalin-2(1 H)-ones.
基金supported by the Hunan Provincial Natural Science Foundation of China (2019JJ20008)the Construct Program of Applied Characteristic Discipline in Hunan University of Science and Engineering
文摘Quinoxaline-3-carboxylates and analogues are prevalent key structural motifs in bioactive natural products and synthetic drugs.However, the practical protocol for preparation of these motifs from simple raw materials under mild conditions remains rare. In this article, we report a facile protocol for the efficient preparation of various quinoxaline-3-carbonyl compounds(30 examples,63%–92%) through oxidation coupling of quinoxalin-2(1H)-ones with readily available carbazates(or acyl hydrazines) in the presence of K_2S_2O_8 as an oxidant in metal-and base-free conditions. When tert-butyl carbazate was used as the coupling reagent,the decarboxylation product 3-(tert-butyl)-1-methylquinoxalin-2(1H)-one was obtained. The application of this process into a gram-scale synthesis can be easily accomplished. Mechanistic investigations reveal that the functionalization of quinoxalin-2(1H)-ones via a free-radical pathway.
基金the National Natural Science Foundation of China(Nos.21732002,22077071)Frontiers Science Center for New Organic Matter,Nankai University(No.63181206)for generous financial support for our programs。
文摘Herein,we report a practical electro-reductive protocol for the direct C-H cyanoalkylation of quinoxalin-2(1 H)-ones via iminyl radical-mediated ring opening.These mild reactions proceed under metal-,reductant-,and reagent-free conditions to provide synthetically useful cyanoalkylated quinoxalin-2(1 H)-ones.
基金We thank the National Natural Science Foundation of China(No.21101085)the Natural Science Foundation of Liaoning Province(No.2015020196)+2 种基金the Liaoning Revitalization Talents Program(No.XLYC1902085)the PetroChina Innovation Foundation(No.2018D-5007-0507)the Research Project Fund of Liaoning Provincial Department of Education(No.L2019037)for the financial supports.
文摘A visible-light-induced tandem radical intramolecular cyclization/arylatiion of quinoxalin-2(1H)-ones with bromodifluoroacetamides is described.This protocol allows efficient access to a variety of valuableα,α-difluoro-y-lactam-fused quinoxalin-2(1H)-ones in moder-ate to good yields under metal-free,mild and redox neutral reaction conditions.This strategy is tolerant of various functional groups and a broad range of substrates.The mechanism experiments suggested an involvement of 5-exo-trig cyclization and a radical pro-cess in this transformation.
基金supported by Youth Innovation and Technology Project of high School in Shandong Province (No. 2019KJC021)Natural Science Foundation of Qinghai Province of China (No. 2020-ZJ-915)。
文摘A mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employing 4Cz IPN as the metal-free photocatalyst and dioxygen(air) as the environmentally benign oxidant. A number of sulfonated quinoxalin-2(1H)-ones were obtained in satisfactory yields with favorable functional group tolerance. Radical trapping experiment and fluorescence quenching experiments were performed to elucidate this visible-light mediated radical reaction process.