Quinoxaline 1, 4-dioxides (QdNOs) are quinox-aline derivatives which have been used as an-timicrobial agents and growth promoters in animals widely. They are also assumed to cure human disease such as anticancer, anti...Quinoxaline 1, 4-dioxides (QdNOs) are quinox-aline derivatives which have been used as an-timicrobial agents and growth promoters in animals widely. They are also assumed to cure human disease such as anticancer, antitubercular and inhibiting parasite. QdNOs such as carbadox and their major metabolites induced a special decline of aldosterone production from the swine adrenal in vivo and in vitro, and thus cause hypovolemia, hyponatremia and hyperkalemia. This can also be expected to be the case for human. As a mainly physiological hormone and a novel steroid with potent mineralocorticoid activity, aldosterone plays an important role in the pathophysiological process of brain, renal and heart disease progression and may be a renal and vascular risk factor. Here, we provide evidence to support the hypothesis that QdNOs may lead potential benefits in aldosterone dysmetabolism disease via the synthesis deficiency of aldosterone in adrenal and/or the cardiovascular tissues. If the hypothesis is true, it may provide a new option into the therapy for aldosterone dysmetabolism disease, especially in cardiovascular system, and thus assume a broader application of QdNOs.展开更多
Dihydro-(2H)-1 .2.4-benzothiadizine-1. 1-dioixdes were prepared in good yields via reductive cyclization of o-nitrobenzenesulfonamidcs with aldchydes promoted by Sml2 under mild and neutral condition.
A straightforward electrochemical reduction of benzo[b]thiophene 1,1-dioxides with HFIP as the hydrogen donor has been reported in an undivided cell under metal-free conditions.Moreover,the tolerance of various functi...A straightforward electrochemical reduction of benzo[b]thiophene 1,1-dioxides with HFIP as the hydrogen donor has been reported in an undivided cell under metal-free conditions.Moreover,the tolerance of various functional groups and scaled-up experiments showed the practicability and potential applications of this methodology.展开更多
A series of novel axially chiral 2,2＇-bipyridine N,N＇-dioxides bearing C1 or C2-symmetry have been synthesized by the use of enantiopure a-amino acids as chiral sources. The absolute stereochemistry of the axial chi...A series of novel axially chiral 2,2＇-bipyridine N,N＇-dioxides bearing C1 or C2-symmetry have been synthesized by the use of enantiopure a-amino acids as chiral sources. The absolute stereochemistry of the axial chirality of these organocatalysts has been clearly assigned by means of CD measurements together with literature protocols. The reactivities and enantioselectivities of these organocatalysts have been examined in the reactions of aromatic aldehydes with allyltrichlorosilane, thus providing the desired products with moderate yields and enantioselectivies.展开更多
The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger sec...The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.展开更多
The alcoholysis mechanism of 1,2-thiazetidine-1,1-dioxide with methanol, in which the relatively stable product is sulfonate ester, has been investigated by quantum chemical method. Our calculations indicate the react...The alcoholysis mechanism of 1,2-thiazetidine-1,1-dioxide with methanol, in which the relatively stable product is sulfonate ester, has been investigated by quantum chemical method. Our calculations indicate the reaction for alcoholysis of 1,2-thiazetidine-1,1-dioxide proceeds via two possible mechanisms: concerted and stepwise. In the stepwise mechanism, two possible reaction pathways can be followed while only one possible reaction pathway can be followed in the concerted mechanism.展开更多
The structural and electronic properties of the solid 5,7-dinitrobenzo-1,2,3,4-tetrazine-1,3-dioxide（DNBTDO） under the hydrostatic pressure of 0~100 GPa were investigated using density functional theory method. The ...The structural and electronic properties of the solid 5,7-dinitrobenzo-1,2,3,4-tetrazine-1,3-dioxide（DNBTDO） under the hydrostatic pressure of 0~100 GPa were investigated using density functional theory method. The predicted crystal structure with the LDA/CA-PZ functional agrees well with the experimental data at the ambient pressure. The structural results show that the b axis is the most compressible, whereas the a and c axes both have slight variation with pressure. The band gap generally decreases with the increasing pressure, which shows that the DNBTDO molecular crystal undergoes an electronic phase transition from semiconductor to metallic system. Through the analysis of band gap, the title compound is most sensitive at 70 GPa. The density of states analysis indicates that the strong peaks split into some small peaks and become wider under compression, which shows the increase of charge overlap and delocalization among the bonded atoms in the system.展开更多
Electrolyte additives are pivotal for stable cycling of rechargeable sodium-ion batteries(SIBs),which dictate the creation of the protective interface film on electrodes.Cyclic sulfur-containing additives,such as1,3,2...Electrolyte additives are pivotal for stable cycling of rechargeable sodium-ion batteries(SIBs),which dictate the creation of the protective interface film on electrodes.Cyclic sulfur-containing additives,such as1,3,2-dioxathiolane-2,2-dioxide(DTD),with the structure of sulfur surrounded by four oxygen atoms,have been proposed but less knowledge is available on the relationship between their molecular structures and interfacial stability.This work compares two similar molecule structure of cyclic sulfurcontaining additives,DTD and ethylene sulfite(ES),to investigate their effects on the electrochemical performance of NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)||hard carbon(HC)pouch cells.Therein,ES with the structure of sulfur surrounded by three oxygen atoms,as electrolyte additive,is investigated in the SIBs for the first time.It is shown that adding 3.0%ES or 2.0%DTD(the optimal proportion)in the Control electrolyte(1 M NaPF_(6)in EC:EMC=3:7 with 5.0%FEC in weight)can improve cyclic stability and rate performance,respectively.Even under the high-temperature conditions,both ES and DTD exhibit good performance,but DTD is superior.Combinations of electrochemical methods,multi-spectroscopy,and theoretical calculations have been employed to evaluate and compare the effects of ES and DTD on sodium-ion battery.They reveal that ES and DTD can generate different content and composition by redox reaction on cathode and anode surface.The more and effective high-valence sulfur-containing components for DTD are the main reason to explain the better effect on DTD.This work shares new insights into the relationship between cyclic sulfur-containing additive molecule structure and electrolyte-electrode interface films effect,which fills the blanks of previous research.展开更多
Alkaloids are natural, semisynthetic or synthetic organic compounds, normally polar with basic chemical properties and containing at least one nitrogen atom in a heterocyclic ring. Some synthetic or semisynthetic subs...Alkaloids are natural, semisynthetic or synthetic organic compounds, normally polar with basic chemical properties and containing at least one nitrogen atom in a heterocyclic ring. Some synthetic or semisynthetic substances resemble the alkaloid architecture. Trivalent nitrogen in these substances is normal;however, some natural and semisynthetic alkaloids have pentavalent nitrogen. The drug pholcodine is a derivative of morphine. Pholcodine has very little addiction- developing effect. It is a semisynthetic alkaloid that was first synthesized in 1950 by Chabrier et al. Pholcodine possesses antitussive (cough relief) properties similar to codeine, morphine and ethylmorphine. The drug was used in liquid formulations as Tuxi and Tuxi Forte, and it is in present use in Tuxidrin as liquid mixture and in tablet form. Pholcodine is an Active Pharmacological Ingredient (API) in tablets and liquid mixtures. Leiras International and Weifa in Norway manufacture medical forms with pholcodine. Several impurities in pholcodine were described by J. Roe in 1997 and by Denk et al. in 2000 and 2002. In addition, several degradation products may be formed in liquid formulations under storage. Some of these products are related not to the original production of pholcodine but rather to its oxidation under storage. The appearance of degradation products strongly depends on the storage temperature and pH of the liquid phase. Pholcodine-N-oxide and pholcodine-N,N’-dioxide are among the degradation (oxidation) products;pholcodine can also degrade to morphine. There is little information about the toxicity of the N-oxide and no information on the N,N’-di- oxide of pholcodine. In this study, the fact that morphine is generated during the storage of formulations containing pholcodine is presented. Another antitussive mixture under the name Cosylan was analyzed to examine the oxidation of ethylmorphine to ethylmorphine-N-oxide. Ethylmorphine is the API in Cosylan.展开更多
A highly efficient asymmetric(3 + 2) cycloaddition of α-diazo pyrazoleamides with silyl enol ethers was realized by employing a chiral N,N’-dioxide-Ni(II) complex catalyst. The process includes the formation of chir...A highly efficient asymmetric(3 + 2) cycloaddition of α-diazo pyrazoleamides with silyl enol ethers was realized by employing a chiral N,N’-dioxide-Ni(II) complex catalyst. The process includes the formation of chiral nickel carbenoid intermediate and the following enantioselective cycloaddition reaction. The desired dihydrofuran O,O-acetal derivatives were obtained in good yields(up to 90%) with high enantioselectivity(up to 99% ee) under mild reaction conditions within short reaction time. On the basis of the determination of the catalyst structure, a possible transition state mode was proposed.展开更多
A potassium organic-inorganic hybrid complex {H2[K（PMo12O40）（CH3CN）3]- （dpdo）2（H2O）}n 1 （dpdo = 4,4＇-bipyridine-N,N＇-dioxide） with special channels for the chain-like assembly of decorated Keggin-type anio...A potassium organic-inorganic hybrid complex {H2[K（PMo12O40）（CH3CN）3]- （dpdo）2（H2O）}n 1 （dpdo = 4,4＇-bipyridine-N,N＇-dioxide） with special channels for the chain-like assembly of decorated Keggin-type anions was synthesized and structurally characterized. The crystal structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Cmcm with a = 20.5328（17）, b = 16.8877（14）, c = 16,1454（14） A, V = 5598.4（8） A^3, Z = 4, C26H29N7O45KMo12P, Mr= 2380.91, Dc = 2.825 g/cm^3,μ = 2.813 mm^-1, F（000） = 4528, the final R = 0.0324 and wR = 0.0880 for 2577 observed reflections with I 〉 2σ（I）. Compound 1 exhibits a 3D network structure with large channels hosting decorated poly-anion chains as vips.展开更多
To develop innovative photocycloadditions between excited carbonyl compounds with C-C bonds and address the absence of catalytic asymmetric ver-sions,herein we report a chiral Lewis acid-mediated catalytic enantiosele...To develop innovative photocycloadditions between excited carbonyl compounds with C-C bonds and address the absence of catalytic asymmetric ver-sions,herein we report a chiral Lewis acid-mediated catalytic enantioselective formal photocycloaddition of excited triplet aldehydes with C-C bond of ben-zocyclobutenones under low catalyst loading(as low as 0.5 mol%).A series of control experiments and density functional theory calculations have con-firmed the existence of diradical intermediates.The Lu(III)/N,N′-dioxide complex plays a crucial role in not only enhancing phosphorescence emission inten-sity but also extending the triplet lifetimes of alde-hydes,which makes it possible for addressing the formidable issue of enantioselective control with in-volved highly reactive triplet intermediates.This ap-proach offers a straightforward avenue to highly enantioenriched 3,4-dihydroisocoumarins in high yields,some of which exhibited anticancer activity upon testing.展开更多
In order to improve the performance of organic luminescent materials,lots of studies have been carried out at the molecular level.However,these materials are mostly applied as solids or aggregates in practical applica...In order to improve the performance of organic luminescent materials,lots of studies have been carried out at the molecular level.However,these materials are mostly applied as solids or aggregates in practical applications,in which the relationship between aggregation structure and luminescent property should be paid more attention.Here,we obtained five phenothiazine 5,5-dioxide(O-PTZ)derivatives with distinct molecular conformations by rational design of chemical structures,and systematically studied their room-temperature phosphorescence(RTP)effect in solid state.It was found that O-PTZ dimers with quasi-equatorial(eq)conformation tended to show strongerπ-πinteraction than quasi-axial(ax)conformers in crystal state,which was more conducive to the generation of RTP.Based on this result,a multi-level structural model of organic solids was proposed to draw the relationship between aggregation structure and RTP effect,just like the research for the structureproperty relationship of proteins.Using this structural model as the guide,boosted RTP efficiency from 1%to 20%was successfully achieved in the corresponding host-vip doping system,showing its wide applicability.展开更多
We report the first asymmetric three-component nucleophilic addition/dearomative[4+2]cycloaddition/isomerization cascade of transient dipoles generated from N-heteroarenes and allenoates with methyleneindolinones in t...We report the first asymmetric three-component nucleophilic addition/dearomative[4+2]cycloaddition/isomerization cascade of transient dipoles generated from N-heteroarenes and allenoates with methyleneindolinones in the presence of chiral N,N′-dioxide/metal complexes.This tandem reaction enabled rapid access to versatile chiral polycyclic N-heterocycles with good to excellent enantioselectivities under mild reaction conditions in spite of the strong background reaction,including 1,2-dihydroisoquinoline,1,2-dihydropyridine derivatives,and others.Meanwhile,a series of control experiments were conducted to elucidate the reaction mechanism and the roles of additives.展开更多
Asymmetric nucleophilic addition of 3-substituted NBoc oxindoles to 3-bromooxindoles was designed to directly construct hetero-3,3′-bisoxindoles,with varying vicinal quaternary carbon stereocenters and N-substituents...Asymmetric nucleophilic addition of 3-substituted NBoc oxindoles to 3-bromooxindoles was designed to directly construct hetero-3,3′-bisoxindoles,with varying vicinal quaternary carbon stereocenters and N-substituents.The reaction progressed efficiently with high yields,good diastereo-and enantioselectivity(up to>99%ee)under mild reaction conditions catalyzed by chiral N,N′-dioxide/metal complexes.This methodology enabled the facile transformation of the generated hetero-3,3’-bisoxindoles into diverse hexahydropyrroloindole alkaloids with potential antiparasitic and anticancer properties.展开更多
文摘Quinoxaline 1, 4-dioxides (QdNOs) are quinox-aline derivatives which have been used as an-timicrobial agents and growth promoters in animals widely. They are also assumed to cure human disease such as anticancer, antitubercular and inhibiting parasite. QdNOs such as carbadox and their major metabolites induced a special decline of aldosterone production from the swine adrenal in vivo and in vitro, and thus cause hypovolemia, hyponatremia and hyperkalemia. This can also be expected to be the case for human. As a mainly physiological hormone and a novel steroid with potent mineralocorticoid activity, aldosterone plays an important role in the pathophysiological process of brain, renal and heart disease progression and may be a renal and vascular risk factor. Here, we provide evidence to support the hypothesis that QdNOs may lead potential benefits in aldosterone dysmetabolism disease via the synthesis deficiency of aldosterone in adrenal and/or the cardiovascular tissues. If the hypothesis is true, it may provide a new option into the therapy for aldosterone dysmetabolism disease, especially in cardiovascular system, and thus assume a broader application of QdNOs.
文摘Dihydro-(2H)-1 .2.4-benzothiadizine-1. 1-dioixdes were prepared in good yields via reductive cyclization of o-nitrobenzenesulfonamidcs with aldchydes promoted by Sml2 under mild and neutral condition.
基金supported by the National Natural Science Foundation of China(21801152 and 21572110)We thank the Youth Innovation Science and Technology Plan of Colleges and Universities in Shandong Province(2021KJ076).
文摘A straightforward electrochemical reduction of benzo[b]thiophene 1,1-dioxides with HFIP as the hydrogen donor has been reported in an undivided cell under metal-free conditions.Moreover,the tolerance of various functional groups and scaled-up experiments showed the practicability and potential applications of this methodology.
基金We thank Beijing Municipal Commission of Edu- cation （No. JC015001200902）, Beijing Municipal Natu- ral Science Foundation （Nos. 710201, 2122008）, Basic Research Foundation of Beijing University of Technol- ogy （X40 15001201101）, Funding Project for Academic Human Resources Development in Institutions ofHigher Learning Under the Jurisdiction of Beijing Municipality （No. PHR201008025）, Doctoral Scientific Research Start-up Foundation of Beijing University of Technology （No. 52015001200701） for financial sup- ports.
文摘A series of novel axially chiral 2,2＇-bipyridine N,N＇-dioxides bearing C1 or C2-symmetry have been synthesized by the use of enantiopure a-amino acids as chiral sources. The absolute stereochemistry of the axial chirality of these organocatalysts has been clearly assigned by means of CD measurements together with literature protocols. The reactivities and enantioselectivities of these organocatalysts have been examined in the reactions of aromatic aldehydes with allyltrichlorosilane, thus providing the desired products with moderate yields and enantioselectivies.
基金Supported by the National Natural Science Foundation of China(No. 2 98730 2 5 )
文摘The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.
文摘The alcoholysis mechanism of 1,2-thiazetidine-1,1-dioxide with methanol, in which the relatively stable product is sulfonate ester, has been investigated by quantum chemical method. Our calculations indicate the reaction for alcoholysis of 1,2-thiazetidine-1,1-dioxide proceeds via two possible mechanisms: concerted and stepwise. In the stepwise mechanism, two possible reaction pathways can be followed while only one possible reaction pathway can be followed in the concerted mechanism.
基金supported by the National Natural Science Foundation of China(No.U1304111)Program for Science&Technology Innovation Talents in Universities of Henan Province(No.14HASTIT039)the Innovation Team of Henan University of Science and Technology(2015XTD001)
文摘The structural and electronic properties of the solid 5,7-dinitrobenzo-1,2,3,4-tetrazine-1,3-dioxide（DNBTDO） under the hydrostatic pressure of 0~100 GPa were investigated using density functional theory method. The predicted crystal structure with the LDA/CA-PZ functional agrees well with the experimental data at the ambient pressure. The structural results show that the b axis is the most compressible, whereas the a and c axes both have slight variation with pressure. The band gap generally decreases with the increasing pressure, which shows that the DNBTDO molecular crystal undergoes an electronic phase transition from semiconductor to metallic system. Through the analysis of band gap, the title compound is most sensitive at 70 GPa. The density of states analysis indicates that the strong peaks split into some small peaks and become wider under compression, which shows the increase of charge overlap and delocalization among the bonded atoms in the system.
基金supported by the National Natural Science Foundation of China(21875076)the Guangdong Provincial International Joint Research Center for Energy Storage Materials(2023A0505090009)the Science and Technology Planning Project of Guangzhou City(2023B03J1278)。
文摘Electrolyte additives are pivotal for stable cycling of rechargeable sodium-ion batteries(SIBs),which dictate the creation of the protective interface film on electrodes.Cyclic sulfur-containing additives,such as1,3,2-dioxathiolane-2,2-dioxide(DTD),with the structure of sulfur surrounded by four oxygen atoms,have been proposed but less knowledge is available on the relationship between their molecular structures and interfacial stability.This work compares two similar molecule structure of cyclic sulfurcontaining additives,DTD and ethylene sulfite(ES),to investigate their effects on the electrochemical performance of NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)||hard carbon(HC)pouch cells.Therein,ES with the structure of sulfur surrounded by three oxygen atoms,as electrolyte additive,is investigated in the SIBs for the first time.It is shown that adding 3.0%ES or 2.0%DTD(the optimal proportion)in the Control electrolyte(1 M NaPF_(6)in EC:EMC=3:7 with 5.0%FEC in weight)can improve cyclic stability and rate performance,respectively.Even under the high-temperature conditions,both ES and DTD exhibit good performance,but DTD is superior.Combinations of electrochemical methods,multi-spectroscopy,and theoretical calculations have been employed to evaluate and compare the effects of ES and DTD on sodium-ion battery.They reveal that ES and DTD can generate different content and composition by redox reaction on cathode and anode surface.The more and effective high-valence sulfur-containing components for DTD are the main reason to explain the better effect on DTD.This work shares new insights into the relationship between cyclic sulfur-containing additive molecule structure and electrolyte-electrode interface films effect,which fills the blanks of previous research.
文摘Alkaloids are natural, semisynthetic or synthetic organic compounds, normally polar with basic chemical properties and containing at least one nitrogen atom in a heterocyclic ring. Some synthetic or semisynthetic substances resemble the alkaloid architecture. Trivalent nitrogen in these substances is normal;however, some natural and semisynthetic alkaloids have pentavalent nitrogen. The drug pholcodine is a derivative of morphine. Pholcodine has very little addiction- developing effect. It is a semisynthetic alkaloid that was first synthesized in 1950 by Chabrier et al. Pholcodine possesses antitussive (cough relief) properties similar to codeine, morphine and ethylmorphine. The drug was used in liquid formulations as Tuxi and Tuxi Forte, and it is in present use in Tuxidrin as liquid mixture and in tablet form. Pholcodine is an Active Pharmacological Ingredient (API) in tablets and liquid mixtures. Leiras International and Weifa in Norway manufacture medical forms with pholcodine. Several impurities in pholcodine were described by J. Roe in 1997 and by Denk et al. in 2000 and 2002. In addition, several degradation products may be formed in liquid formulations under storage. Some of these products are related not to the original production of pholcodine but rather to its oxidation under storage. The appearance of degradation products strongly depends on the storage temperature and pH of the liquid phase. Pholcodine-N-oxide and pholcodine-N,N’-dioxide are among the degradation (oxidation) products;pholcodine can also degrade to morphine. There is little information about the toxicity of the N-oxide and no information on the N,N’-di- oxide of pholcodine. In this study, the fact that morphine is generated during the storage of formulations containing pholcodine is presented. Another antitussive mixture under the name Cosylan was analyzed to examine the oxidation of ethylmorphine to ethylmorphine-N-oxide. Ethylmorphine is the API in Cosylan.
基金the National Natural Science Foundation of China(No. 22188101)Sichuan Science and Technology Program (No.2021YJ0561)Sichuan University (No. 2020SCUNL204)for financial support。
文摘A highly efficient asymmetric(3 + 2) cycloaddition of α-diazo pyrazoleamides with silyl enol ethers was realized by employing a chiral N,N’-dioxide-Ni(II) complex catalyst. The process includes the formation of chiral nickel carbenoid intermediate and the following enantioselective cycloaddition reaction. The desired dihydrofuran O,O-acetal derivatives were obtained in good yields(up to 90%) with high enantioselectivity(up to 99% ee) under mild reaction conditions within short reaction time. On the basis of the determination of the catalyst structure, a possible transition state mode was proposed.
基金supported by the Natural Science Foundation of Henan Province and the Science Research Startup Foundation of Henan Normal University (NO. 0707)
文摘A potassium organic-inorganic hybrid complex {H2[K（PMo12O40）（CH3CN）3]- （dpdo）2（H2O）}n 1 （dpdo = 4,4＇-bipyridine-N,N＇-dioxide） with special channels for the chain-like assembly of decorated Keggin-type anions was synthesized and structurally characterized. The crystal structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Cmcm with a = 20.5328（17）, b = 16.8877（14）, c = 16,1454（14） A, V = 5598.4（8） A^3, Z = 4, C26H29N7O45KMo12P, Mr= 2380.91, Dc = 2.825 g/cm^3,μ = 2.813 mm^-1, F（000） = 4528, the final R = 0.0324 and wR = 0.0880 for 2577 observed reflections with I 〉 2σ（I）. Compound 1 exhibits a 3D network structure with large channels hosting decorated poly-anion chains as vips.
基金the National Key Research and Development Program of China(grant no.2022YFA1504301)the National Natural Science Foundation of China(grant no.92256302)for financial support.
文摘To develop innovative photocycloadditions between excited carbonyl compounds with C-C bonds and address the absence of catalytic asymmetric ver-sions,herein we report a chiral Lewis acid-mediated catalytic enantioselective formal photocycloaddition of excited triplet aldehydes with C-C bond of ben-zocyclobutenones under low catalyst loading(as low as 0.5 mol%).A series of control experiments and density functional theory calculations have con-firmed the existence of diradical intermediates.The Lu(III)/N,N′-dioxide complex plays a crucial role in not only enhancing phosphorescence emission inten-sity but also extending the triplet lifetimes of alde-hydes,which makes it possible for addressing the formidable issue of enantioselective control with in-volved highly reactive triplet intermediates.This ap-proach offers a straightforward avenue to highly enantioenriched 3,4-dihydroisocoumarins in high yields,some of which exhibited anticancer activity upon testing.
基金National Natural Science Foundation of China,Grant/Award Numbers:52273191,22235006Natural Science Foundation of Tianjin City,Grant/Award Number:22JCYBJC00760+3 种基金Open Project Program of Wuhan National Laboratory for Optoelectronics,Grant/Award Number:2020WNLOKF013starting Grants of Tianjin University and Tianjin GovernmentIndependent Innovation Fund of Tianjin University,Grant/Award Number:2023XPD-0014Guangzhou AIE Higher Research Institute。
文摘In order to improve the performance of organic luminescent materials,lots of studies have been carried out at the molecular level.However,these materials are mostly applied as solids or aggregates in practical applications,in which the relationship between aggregation structure and luminescent property should be paid more attention.Here,we obtained five phenothiazine 5,5-dioxide(O-PTZ)derivatives with distinct molecular conformations by rational design of chemical structures,and systematically studied their room-temperature phosphorescence(RTP)effect in solid state.It was found that O-PTZ dimers with quasi-equatorial(eq)conformation tended to show strongerπ-πinteraction than quasi-axial(ax)conformers in crystal state,which was more conducive to the generation of RTP.Based on this result,a multi-level structural model of organic solids was proposed to draw the relationship between aggregation structure and RTP effect,just like the research for the structureproperty relationship of proteins.Using this structural model as the guide,boosted RTP efficiency from 1%to 20%was successfully achieved in the corresponding host-vip doping system,showing its wide applicability.
基金the National Natural Science Foundation of China(grant no.21772127).
文摘We report the first asymmetric three-component nucleophilic addition/dearomative[4+2]cycloaddition/isomerization cascade of transient dipoles generated from N-heteroarenes and allenoates with methyleneindolinones in the presence of chiral N,N′-dioxide/metal complexes.This tandem reaction enabled rapid access to versatile chiral polycyclic N-heterocycles with good to excellent enantioselectivities under mild reaction conditions in spite of the strong background reaction,including 1,2-dihydroisoquinoline,1,2-dihydropyridine derivatives,and others.Meanwhile,a series of control experiments were conducted to elucidate the reaction mechanism and the roles of additives.
基金support from the National Natural Science Foundation of China(grant nos.21625205 and U19A2014).
文摘Asymmetric nucleophilic addition of 3-substituted NBoc oxindoles to 3-bromooxindoles was designed to directly construct hetero-3,3′-bisoxindoles,with varying vicinal quaternary carbon stereocenters and N-substituents.The reaction progressed efficiently with high yields,good diastereo-and enantioselectivity(up to>99%ee)under mild reaction conditions catalyzed by chiral N,N′-dioxide/metal complexes.This methodology enabled the facile transformation of the generated hetero-3,3’-bisoxindoles into diverse hexahydropyrroloindole alkaloids with potential antiparasitic and anticancer properties.
