A novel method for synthesis of quinazoline through the hydrogen transfer/annulation reaction using 2-nitrobenzyl alcohol and benzylamine as starting materials is presented.The reaction is catalyzed by a ruthenium(II)...A novel method for synthesis of quinazoline through the hydrogen transfer/annulation reaction using 2-nitrobenzyl alcohol and benzylamine as starting materials is presented.The reaction is catalyzed by a ruthenium(II)complex bearing a N-heterocyclic carbene nitrogen phosphine(CNP)ligand.The pronouncedα-donating capacity of the carbene within the CNP ligand of the catalyst plays a crucial role in stabilizing the catalytically active species.Additionally,the hemilability of the nitrogen facilitates the creation of coordination vacancies,which are essential for the activation of reaction substrate molecules.The synergistic interplay between these two functionalities markedly enhances catalytic efficiency.This catalytic system shows the significant catalytic activity and selectivity,along with a broad substrate adaptability.All substrates yield the target product in good to excellent yields with the maximum yield reaching 95%.Control experiments have substantiated that benzaldehyde and phenylmethanimine may serve as intermediates in the reaction,thereby reinforcing the role of benzylamine as both a hydrogen donor and a nitrogen source in the process.展开更多
The first example of TBAI/H_(2)O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtaine...The first example of TBAI/H_(2)O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtained in good to excellent yields with exclusive chemoselectivities and excellent regioselectivities. The H-hydrogen bond served as a key factor for the electrocatalytic production of aminomethyl radical at lower oxidative potential.展开更多
Indoles and their derivatives are an important class of N-heterocycles.In this article,iridium-catalyzed annulation reactions of N-aryl-2-aminopyridines to synthesize indole derivatives are designed and developed,whic...Indoles and their derivatives are an important class of N-heterocycles.In this article,iridium-catalyzed annulation reactions of N-aryl-2-aminopyridines to synthesize indole derivatives are designed and developed,which utilize vinylene carbonate as a new C2 synthon.This protocol is expected to provide a facile and useful access to various indole derivatives.展开更多
In this study, we proposed a novel method to investigate the advanced oxidation process of neonicotinoids(NNIs) from the perspective of concomitant chemiluminescence(CL) reaction. It was found that in the presence of ...In this study, we proposed a novel method to investigate the advanced oxidation process of neonicotinoids(NNIs) from the perspective of concomitant chemiluminescence(CL) reaction. It was found that in the presence of cobalt ions with cyanoimino NNIs, acetamiprid(ACE) and thiacloprid(THI), could promote peroxymonosulfate and Ru(bpy)_(3)^(2+) to produce strong CL, but no CL occurred with nitro-involved NNIs as alternatives. Experimental dada from UV absorption spectra and chemiluminescence spectra suggested that new cyclic compounds might be formed during the reaction. Based on the results of free radical scavenging experiment and mass spectra, a new degradation and reaction mechanism of cyanoiminocontaining NNIs was proposed. ACE or THI were first attacked by SO_(4)^(·-) to form benzyl radicals, which in turn reacted with the carbon atoms of cyano group through electrophilic addition reaction in the formation of intramolecular ring. Then a redox reaction between Ru(bpy)_(3)^(3+) and imino group immediately took place with CL emission(610 nm). The new mechanistic knowledge would be meaningful for other contaminants for their interactions with PMS.展开更多
Palladium-catalyzed oxidative formal [4 + 1] annulation of pyridine-substituted acrylonitriles toward divergent fused N-heterocycles synthesis is reported. The heterodifunctionalization reaction with Cu(OAc);and urea ...Palladium-catalyzed oxidative formal [4 + 1] annulation of pyridine-substituted acrylonitriles toward divergent fused N-heterocycles synthesis is reported. The heterodifunctionalization reaction with Cu(OAc);and urea as the nitrogen source accesses to nitrile-substituted pyrazolo[1,5-a]pyridines in moderate to good yields, while the homodifunctionalization reaction with FeBr;leads to synthesis of nitrilesubstituted indolizines in excellent yields.展开更多
A[Cp*RhCl_(2)]_(2)-catalyzed intramolecular annulation reaction via aminoalkylation of alkenes with diazo compounds has been developed to construct highly-functionalized isoindolinones.This approach exhibits step econ...A[Cp*RhCl_(2)]_(2)-catalyzed intramolecular annulation reaction via aminoalkylation of alkenes with diazo compounds has been developed to construct highly-functionalized isoindolinones.This approach exhibits step economy,mild reaction conditions,and good functional group tolerance,facilitating access to a wide range of highly-valuable functionalized isoindolinones with high level of yields(up to 99%yield).展开更多
in this work, the phosphine-catalyzed annulation reactions between modified allylic derivatives and polar 1,1-dicyano-1,3-dienes have been studied. In the catalysis of PPh3 （20 mol%）, a [4 ＋ 1 ] annulation reaction...in this work, the phosphine-catalyzed annulation reactions between modified allylic derivatives and polar 1,1-dicyano-1,3-dienes have been studied. In the catalysis of PPh3 （20 mol%）, a [4 ＋ 1 ] annulation reaction is realized between a series of l,l-dicyano-2,4-diaryl-1,3-dienes and ethoxycarbonyl-activated allylic acetate, producing polysubstituted cyclopentenes in modest to excellent yields. It is also observed that the substituents of both 1,3-dienes and allylic derivatives have a significant influence on the annulation mode： under the catalysis of PPh3 or PBu3 （20 mol%）, regioselective [3 ＋ 2] annulation products are formed from differently substituted substratcs.展开更多
A phosphine-catalyzed [4＋2] annulation of a-substituted allenoate with exocyclic alkene moiety of oxindoles or indan-1,3-diones has been developed. Thus, under the catalysis of PPh3 （20 mol%）, a series of spirooxin...A phosphine-catalyzed [4＋2] annulation of a-substituted allenoate with exocyclic alkene moiety of oxindoles or indan-1,3-diones has been developed. Thus, under the catalysis of PPh3 （20 mol%）, a series of spirooxindole- or spiroindan-1,3-dione-cyclohexenes have been obtained in moderate to excellent yields and regioselectivity from the annulations of a-methyl allenoates with 3-methyleneoxindoles or 2-methyleneindan-1,3-diones. This method offers an easy access to structurally novel spirocyclohexenes.展开更多
An inexpensive BF3·Et20-catalyzed annulation reaction of arylacetaldehydes with arylalkynes has been developed. Various substituted phenylacetaldehydes and phenylacetylenes can undergo this reaction, producing co...An inexpensive BF3·Et20-catalyzed annulation reaction of arylacetaldehydes with arylalkynes has been developed. Various substituted phenylacetaldehydes and phenylacetylenes can undergo this reaction, producing corresponding α-aryl substituted naphthalene derivatives. Use of inexpensive and readily available BF3·Et20 catalyst constitutes the most attractive advantage of this transformation.展开更多
Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantiose...Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantioselective annulation of SCBs with terminal alkynes remains a challenge.Herein,we report a rhodium-catalyzed asymmetric annulation reaction of SCBs with terminal alkynes,which relies on the newly identified chiral sulfinamide phosphine ligand Ming-Phos.This catalytic system exhibits unique effects under mild conditions,leading to the direct synthesis of structurally diverse chiral silacycles in moderate to good yields with high enantioselectivities(up to 95%ee).展开更多
文摘A novel method for synthesis of quinazoline through the hydrogen transfer/annulation reaction using 2-nitrobenzyl alcohol and benzylamine as starting materials is presented.The reaction is catalyzed by a ruthenium(II)complex bearing a N-heterocyclic carbene nitrogen phosphine(CNP)ligand.The pronouncedα-donating capacity of the carbene within the CNP ligand of the catalyst plays a crucial role in stabilizing the catalytically active species.Additionally,the hemilability of the nitrogen facilitates the creation of coordination vacancies,which are essential for the activation of reaction substrate molecules.The synergistic interplay between these two functionalities markedly enhances catalytic efficiency.This catalytic system shows the significant catalytic activity and selectivity,along with a broad substrate adaptability.All substrates yield the target product in good to excellent yields with the maximum yield reaching 95%.Control experiments have substantiated that benzaldehyde and phenylmethanimine may serve as intermediates in the reaction,thereby reinforcing the role of benzylamine as both a hydrogen donor and a nitrogen source in the process.
基金financial support from the University of South China。
文摘The first example of TBAI/H_(2)O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtained in good to excellent yields with exclusive chemoselectivities and excellent regioselectivities. The H-hydrogen bond served as a key factor for the electrocatalytic production of aminomethyl radical at lower oxidative potential.
文摘Indoles and their derivatives are an important class of N-heterocycles.In this article,iridium-catalyzed annulation reactions of N-aryl-2-aminopyridines to synthesize indole derivatives are designed and developed,which utilize vinylene carbonate as a new C2 synthon.This protocol is expected to provide a facile and useful access to various indole derivatives.
基金financial supports from the National Natural Science Foundation of China(Nos.81960600and 81760601)the Natural Science Foundation of Jiangxi Province(Nos.20192BAB205089 and 20192BAB205091)。
文摘In this study, we proposed a novel method to investigate the advanced oxidation process of neonicotinoids(NNIs) from the perspective of concomitant chemiluminescence(CL) reaction. It was found that in the presence of cobalt ions with cyanoimino NNIs, acetamiprid(ACE) and thiacloprid(THI), could promote peroxymonosulfate and Ru(bpy)_(3)^(2+) to produce strong CL, but no CL occurred with nitro-involved NNIs as alternatives. Experimental dada from UV absorption spectra and chemiluminescence spectra suggested that new cyclic compounds might be formed during the reaction. Based on the results of free radical scavenging experiment and mass spectra, a new degradation and reaction mechanism of cyanoiminocontaining NNIs was proposed. ACE or THI were first attacked by SO_(4)^(·-) to form benzyl radicals, which in turn reacted with the carbon atoms of cyano group through electrophilic addition reaction in the formation of intramolecular ring. Then a redox reaction between Ru(bpy)_(3)^(3+) and imino group immediately took place with CL emission(610 nm). The new mechanistic knowledge would be meaningful for other contaminants for their interactions with PMS.
基金financial support from the Natural Science Foundation of Jiangxi Provincial Education Department (Nos. GJJ201422, GJJ190754, GJJ190776)Science and Technology Project of Ganzhou City。
文摘Palladium-catalyzed oxidative formal [4 + 1] annulation of pyridine-substituted acrylonitriles toward divergent fused N-heterocycles synthesis is reported. The heterodifunctionalization reaction with Cu(OAc);and urea as the nitrogen source accesses to nitrile-substituted pyrazolo[1,5-a]pyridines in moderate to good yields, while the homodifunctionalization reaction with FeBr;leads to synthesis of nitrilesubstituted indolizines in excellent yields.
文摘A[Cp*RhCl_(2)]_(2)-catalyzed intramolecular annulation reaction via aminoalkylation of alkenes with diazo compounds has been developed to construct highly-functionalized isoindolinones.This approach exhibits step economy,mild reaction conditions,and good functional group tolerance,facilitating access to a wide range of highly-valuable functionalized isoindolinones with high level of yields(up to 99%yield).
基金Acknowledgement Financial support from National Natural Science Foundation of China （Nos. 21072100 21121002 21272119） is gratefully acknowledged.
文摘in this work, the phosphine-catalyzed annulation reactions between modified allylic derivatives and polar 1,1-dicyano-1,3-dienes have been studied. In the catalysis of PPh3 （20 mol%）, a [4 ＋ 1 ] annulation reaction is realized between a series of l,l-dicyano-2,4-diaryl-1,3-dienes and ethoxycarbonyl-activated allylic acetate, producing polysubstituted cyclopentenes in modest to excellent yields. It is also observed that the substituents of both 1,3-dienes and allylic derivatives have a significant influence on the annulation mode： under the catalysis of PPh3 or PBu3 （20 mol%）, regioselective [3 ＋ 2] annulation products are formed from differently substituted substratcs.
基金Financial support from the Fundamental Research Funds for the Central Universities （No. KYZ201749） and the National Natural Science Foundation of China （Nos. 21272119, J1103306） are gratefully acknowledged.
文摘A phosphine-catalyzed [4＋2] annulation of a-substituted allenoate with exocyclic alkene moiety of oxindoles or indan-1,3-diones has been developed. Thus, under the catalysis of PPh3 （20 mol%）, a series of spirooxindole- or spiroindan-1,3-dione-cyclohexenes have been obtained in moderate to excellent yields and regioselectivity from the annulations of a-methyl allenoates with 3-methyleneoxindoles or 2-methyleneindan-1,3-diones. This method offers an easy access to structurally novel spirocyclohexenes.
基金the financial supports from Sichuan Provincial Department of Education (11ZA108)National Natural Science Foundation of China (21202109 and 21072140)+1 种基金Special Funds of Sichuan Normal University for Sharing the Large Precision Equipments (DJ2012-07,DJ2011-16)Sichuan Normal University
文摘An inexpensive BF3·Et20-catalyzed annulation reaction of arylacetaldehydes with arylalkynes has been developed. Various substituted phenylacetaldehydes and phenylacetylenes can undergo this reaction, producing corresponding α-aryl substituted naphthalene derivatives. Use of inexpensive and readily available BF3·Et20 catalyst constitutes the most attractive advantage of this transformation.
基金the funding support of the National Key R&D Program of China(No.2021YFF0701601)NSFC(Nos.22031004 and 21921003)+1 种基金Shanghai Municipal Education Commission(No.20212308)Science and Technology Commission of Shanghai Municipality(No.23ZR1404800).
文摘Asymmetric ring-expansion reactions of silacyclobutanes(SCBs)with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds.However,the achievement of highly enantioselective annulation of SCBs with terminal alkynes remains a challenge.Herein,we report a rhodium-catalyzed asymmetric annulation reaction of SCBs with terminal alkynes,which relies on the newly identified chiral sulfinamide phosphine ligand Ming-Phos.This catalytic system exhibits unique effects under mild conditions,leading to the direct synthesis of structurally diverse chiral silacycles in moderate to good yields with high enantioselectivities(up to 95%ee).
