α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organi...α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organic compounds with diverse structures.Herein,the advances in the research areas ofα-trifluoromethyl ketone synthesis and their defluorination reactions are reviewed.Discussion on the mechanisms of the typical reactions has also been provided,in hope of affording some guides to the chemistry ofα-trifluoromethyl ketones in the synthetic methods toward themselves and their derivatives.展开更多
The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively red...The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.展开更多
A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the aci...A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the acidic alumina surface effectively activate the carbonyl group ofα,β-unsaturated ketones,significantly enhancing the electrophilicity of theβ-carbon and thereby facilitating selective alkylation at the C3 position of imidazo[1,2-a]pyridines.This method demonstrates excellent functional group compatibility,mild reaction conditions,low reagent costs,and operational simplicity,providing a novel strategy for the efficient synthesis of alkylated imidazo[1,2-a]pyridine derivatives.展开更多
Objective Hypoxia plays a critical role in the pathophysiology of cardiomyopathy,myocardial infarction,and heart failure.Promoting ketone metabolism has been shown to be beneficial for myocardial cells under hypoxic c...Objective Hypoxia plays a critical role in the pathophysiology of cardiomyopathy,myocardial infarction,and heart failure.Promoting ketone metabolism has been shown to be beneficial for myocardial cells under hypoxic conditions.However,the expression and regulatory mechanisms of key enzymes in the ketone pathway under hypoxic conditions are still unclear.This study aimed to investigate the effects of hypoxia on the expression of key enzymes in the ketone metabolic pathway and the underlying regulatory mechanisms involved.Methods H9C2 myocardial cells were cultured for 6 h in an oxygen-glucose-deprived state,and the expression of various genes was detected by quantitative real-time PCR.ELISA and lactate dehydrogenase(LDH)cytotoxicity assay were used to measure CoAs,itaconic acid,and LDH levels,respectively,and the dependence of gene expression on hypoxia-inducible factor-1 alpha(HIF-1α)was evaluated using the inhibitor LW6.Results H9C2 cardiomyocytes exhibited increased ketone body metabolism in response to hypoxia.Hypoxia induced the expression of the ketone body enzymes succinyl-CoA:3-oxoacid CoA transferase(SCOT/OXCT1),3-hydroxybutyrate dehy-drogenase 2(BDH2),and acyl-CoA:cholesterol acyltransferase 1(ACAT1)in cardiomyocytes,with a concomitant increase in the level of acyl-CoA and a decrease in the level of succinyl-CoA.The HIF-1αinhibitor LW6 could partially reverse the expression of BDH2 and ACAT1,as well as the levels of succinyl-CoA.Interestingly,however,hypoxia-induced SCOT/OXCT1 expression was not regulated by the HIF-1αinhibitor.In addition,hypoxia promoted the expression of inflamma-tory factors.Conclusion These data confirm the critical role of ketone metabolism in myocardial hypoxia and help to elucidate the patho-physiology of cardiomyopathy,myocardial infarction and heart failure.展开更多
C-C coupling and hydrodeoxygenation are two important reactions in the production of sustainable aviation fuels(SAFs)with lignocellulose derived oxygenates.However,it is challenging to integrate them into a one-step p...C-C coupling and hydrodeoxygenation are two important reactions in the production of sustainable aviation fuels(SAFs)with lignocellulose derived oxygenates.However,it is challenging to integrate them into a one-step process because the necessity of oxygen containing functional groups in the C-C coupling reactions.Herein,jet fuel range polycycloalkanes and branched alkanes were directly synthesized by a cascade self-aldol condensation/hydrodeoxygenation reaction of lignocellulosic ketones over a zirconium phosphate loaded calcium modified nickel catalyst(NiCa/ZrP)that was prepared by a simple incipient impregnation method.Compared with the catalyst systems that have been reported in literature,the NiCa/ZrP catalyst have many advantages such as fewer step,easier operation and preparation,lower equipment investment and cost,wider applicability,etc.Moreover,the NiCa/ZrP is also applicable for the direct production of jet fuel range alkanes with lignocellulosic ketones and/or alcohols by a cascade dehydrogenation/aldol condensation/hydrodeoxygenation reaction.This work gives a new idea about the reduction of energy consumption and cost by catalyst designing in the manufacture of SAFs from lignocellulose.展开更多
Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation...Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is...展开更多
Peptidyl epoxyketones were potential antitumor agents due to their 20S proteasome inhibitory activities. Based on their structures and special inhibitory mechanism, a series of compounds were designed by linking the e...Peptidyl epoxyketones were potential antitumor agents due to their 20S proteasome inhibitory activities. Based on their structures and special inhibitory mechanism, a series of compounds were designed by linking the epoxyketone moiety （the Cterminal pharmacophore） and the peptide backbones. To make these compounds, we used a novel method to prepare the terminal α,β-unsaturated ketone, the crucial intermediate, from Weinreb amide with satisfactory yield （62%-65%）.展开更多
ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and...ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and diethyl ketone by the one-step synthesis method over this catalyst were studied,and meanwhile,the impact of the catalyst preparation conditions and the reaction conditions on catalyst performance was also investigated.It was observed that under the conditions when Ni loading was 25%,calcination temperature was 400℃ and reduction temperature was 410℃,this catalyst had good catalytic performance on the reaction.The suitable reaction conditions were achieved:reaction temperature was 400℃;reaction at atmospheric pressure;liquid hourly space velocity of raw material of 0.5 h 1 ;and the molar ratio of(methanol)/(methyl ethyl ketone)/(water) was equal to 1/1/1.Under such conditions,the conversion of methyl ethyl ketone could achieve 41.7%,and the overall selectivity of methyl isopropyl ketone and diethyl ketone could achieve 83.3%,which was comparable to the conversion of 38.1% and the selectivity of 82.2% achieved by using palladium as the active material.The good stability made this catalyst have good prospects for industrial application.展开更多
A combination of tetrachlorosilane（TCS） and phenol in dichloromethane was found to be an efficient reagent for hydro-chlorination ofα,β-unsaturated ketones to afford the correspondingβ-chloroketones in good yield...A combination of tetrachlorosilane（TCS） and phenol in dichloromethane was found to be an efficient reagent for hydro-chlorination ofα,β-unsaturated ketones to afford the correspondingβ-chloroketones in good yield at ambient temperature. Reactions of the titled compounds with TCS-NaN_3 as well as with nitriles utilizing TCS-ZnCl_2 to give 1,5-disubstituted tetrazole derivatives orβ-amido ketones respectively are also described.展开更多
A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc has been achieved.A series ofα-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization...A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc has been achieved.A series ofα-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization of 2-aryl-1,1-dibromoalkenes.展开更多
In this paper, an efficient synthesis of cyclopentenyl ketones and cyclohexenyl ketones through tertiary phosphine catalyzed [3 ＋ 2] and [4 ＋ 2] annulations of 1,2-allenic ketones with activated alkenes has been dev...In this paper, an efficient synthesis of cyclopentenyl ketones and cyclohexenyl ketones through tertiary phosphine catalyzed [3 ＋ 2] and [4 ＋ 2] annulations of 1,2-allenic ketones with activated alkenes has been developed. Compared with published synthetic methods on cyclopentenyl ketones and cyclohexenyl ketones, the protocols developed in this paper have the advantages such as readily available starting materials, mild reaction conditions and high efficiency.展开更多
A reaction of α-bromo aromatic ketones in water with microwave irradiation gave the corresponding α-hydroxy aromatic ketones in good yields. The use of microwaves was found to significantly improve yields and shorte...A reaction of α-bromo aromatic ketones in water with microwave irradiation gave the corresponding α-hydroxy aromatic ketones in good yields. The use of microwaves was found to significantly improve yields and shorten the reaction time. This reaction afforded a very clean, convenient method for the synthesis of α-hydroxy aromatic ketones.展开更多
When ketones were treated with ammonium chloride and Oxone in MeOH at room temperature, a direct or-chlorination of ketones was occurred and a series of the corresponding α-chloroketones were obtained in moderate to ...When ketones were treated with ammonium chloride and Oxone in MeOH at room temperature, a direct or-chlorination of ketones was occurred and a series of the corresponding α-chloroketones were obtained in moderate to good yields after 24 h. In this reaction, ammonium chloride was used as the source of chlorine and Oxone was used as an oxidant. This method was simple, convenient and providing a novel procedure for preparation of α-chloroketones.展开更多
Novel reusable MnOx‐N@C catalyst has been developed for the direct oxidation of N‐heterocycles under solvent‐free conditions using TBHP as benign oxidant to give the corresponding N‐heterocyclic ketones. The catal...Novel reusable MnOx‐N@C catalyst has been developed for the direct oxidation of N‐heterocycles under solvent‐free conditions using TBHP as benign oxidant to give the corresponding N‐heterocyclic ketones. The catalytic system exhibited a broad substrate scope and excellent regi‐oselectivity, as well as being amenable to gram‐scale synthesis. This MnOx‐N@C catalyst also showed good reusability and was successfully recycled six times without any significant loss of activity.展开更多
Ketones smoothly reacted with NBS in the presence of a catalytic amount of ptoluenesulfonic acid to give α-bromoketones in good yields in typical ionic liquids, such as [bmim]PF6 and [bmpy]Tf2N, and the ionic liquids...Ketones smoothly reacted with NBS in the presence of a catalytic amount of ptoluenesulfonic acid to give α-bromoketones in good yields in typical ionic liquids, such as [bmim]PF6 and [bmpy]Tf2N, and the ionic liquids could be repeatedly used for the same reaction after the extraction of the α-bromoketones. Then, the one-pot conversion of ketones into thiazoles by the treatment with NBS, and subsequently with thioamides could be also carried out in [bmim]PF6 and [bmpy]Tf2N, respectively Thus, [bmim]PF6 and [bmpy]Tf2N could be used as recyclable reaction media for the preparation α-bromoketones and thiazoles from ketones.展开更多
A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition m...A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .展开更多
Cerium trichloride heptahydrate(CeCl_3·7H_2O) was found to be an efficient and recyclable catalyst for the three-component direct Mannich reaction of anilines and benzaldehydes with acetophenone.This protocol has...Cerium trichloride heptahydrate(CeCl_3·7H_2O) was found to be an efficient and recyclable catalyst for the three-component direct Mannich reaction of anilines and benzaldehydes with acetophenone.This protocol has advantages of high yield,no environmental pollution,mild condition,and simple work-up procedure.展开更多
Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chlorometh...Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.展开更多
The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfa...The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.展开更多
Michael addition of indole and pyrrole to a variety of α, β-unsaturated ketones was efficiently promoted by a catalytic amount of GaCl3 in aqueous media to afford the corresponding products in good to excellent yields.
文摘α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organic compounds with diverse structures.Herein,the advances in the research areas ofα-trifluoromethyl ketone synthesis and their defluorination reactions are reviewed.Discussion on the mechanisms of the typical reactions has also been provided,in hope of affording some guides to the chemistry ofα-trifluoromethyl ketones in the synthetic methods toward themselves and their derivatives.
文摘The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.
文摘A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the acidic alumina surface effectively activate the carbonyl group ofα,β-unsaturated ketones,significantly enhancing the electrophilicity of theβ-carbon and thereby facilitating selective alkylation at the C3 position of imidazo[1,2-a]pyridines.This method demonstrates excellent functional group compatibility,mild reaction conditions,low reagent costs,and operational simplicity,providing a novel strategy for the efficient synthesis of alkylated imidazo[1,2-a]pyridine derivatives.
基金supported by the Specialized Research Fund for the National Natural Science Foundation of China(No.81973511).
文摘Objective Hypoxia plays a critical role in the pathophysiology of cardiomyopathy,myocardial infarction,and heart failure.Promoting ketone metabolism has been shown to be beneficial for myocardial cells under hypoxic conditions.However,the expression and regulatory mechanisms of key enzymes in the ketone pathway under hypoxic conditions are still unclear.This study aimed to investigate the effects of hypoxia on the expression of key enzymes in the ketone metabolic pathway and the underlying regulatory mechanisms involved.Methods H9C2 myocardial cells were cultured for 6 h in an oxygen-glucose-deprived state,and the expression of various genes was detected by quantitative real-time PCR.ELISA and lactate dehydrogenase(LDH)cytotoxicity assay were used to measure CoAs,itaconic acid,and LDH levels,respectively,and the dependence of gene expression on hypoxia-inducible factor-1 alpha(HIF-1α)was evaluated using the inhibitor LW6.Results H9C2 cardiomyocytes exhibited increased ketone body metabolism in response to hypoxia.Hypoxia induced the expression of the ketone body enzymes succinyl-CoA:3-oxoacid CoA transferase(SCOT/OXCT1),3-hydroxybutyrate dehy-drogenase 2(BDH2),and acyl-CoA:cholesterol acyltransferase 1(ACAT1)in cardiomyocytes,with a concomitant increase in the level of acyl-CoA and a decrease in the level of succinyl-CoA.The HIF-1αinhibitor LW6 could partially reverse the expression of BDH2 and ACAT1,as well as the levels of succinyl-CoA.Interestingly,however,hypoxia-induced SCOT/OXCT1 expression was not regulated by the HIF-1αinhibitor.In addition,hypoxia promoted the expression of inflamma-tory factors.Conclusion These data confirm the critical role of ketone metabolism in myocardial hypoxia and help to elucidate the patho-physiology of cardiomyopathy,myocardial infarction and heart failure.
基金supported by the National Key R&D Program of China(2022YFB4201802)the National Natural Science Foundation of China(22178335)DICP(DICP I202448)。
文摘C-C coupling and hydrodeoxygenation are two important reactions in the production of sustainable aviation fuels(SAFs)with lignocellulose derived oxygenates.However,it is challenging to integrate them into a one-step process because the necessity of oxygen containing functional groups in the C-C coupling reactions.Herein,jet fuel range polycycloalkanes and branched alkanes were directly synthesized by a cascade self-aldol condensation/hydrodeoxygenation reaction of lignocellulosic ketones over a zirconium phosphate loaded calcium modified nickel catalyst(NiCa/ZrP)that was prepared by a simple incipient impregnation method.Compared with the catalyst systems that have been reported in literature,the NiCa/ZrP catalyst have many advantages such as fewer step,easier operation and preparation,lower equipment investment and cost,wider applicability,etc.Moreover,the NiCa/ZrP is also applicable for the direct production of jet fuel range alkanes with lignocellulosic ketones and/or alcohols by a cascade dehydrogenation/aldol condensation/hydrodeoxygenation reaction.This work gives a new idea about the reduction of energy consumption and cost by catalyst designing in the manufacture of SAFs from lignocellulose.
基金This work was financially supported by the National Natural Science Foundation of China(No.15076017).
文摘Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is...
基金National Natural Science Foundation of China (Grant No. 30772650 and 20772008)
文摘Peptidyl epoxyketones were potential antitumor agents due to their 20S proteasome inhibitory activities. Based on their structures and special inhibitory mechanism, a series of compounds were designed by linking the epoxyketone moiety （the Cterminal pharmacophore） and the peptide backbones. To make these compounds, we used a novel method to prepare the terminal α,β-unsaturated ketone, the crucial intermediate, from Weinreb amide with satisfactory yield （62%-65%）.
基金Supported by the National Science and Technology Support Program Project (2006BAE03B06)
文摘ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and diethyl ketone by the one-step synthesis method over this catalyst were studied,and meanwhile,the impact of the catalyst preparation conditions and the reaction conditions on catalyst performance was also investigated.It was observed that under the conditions when Ni loading was 25%,calcination temperature was 400℃ and reduction temperature was 410℃,this catalyst had good catalytic performance on the reaction.The suitable reaction conditions were achieved:reaction temperature was 400℃;reaction at atmospheric pressure;liquid hourly space velocity of raw material of 0.5 h 1 ;and the molar ratio of(methanol)/(methyl ethyl ketone)/(water) was equal to 1/1/1.Under such conditions,the conversion of methyl ethyl ketone could achieve 41.7%,and the overall selectivity of methyl isopropyl ketone and diethyl ketone could achieve 83.3%,which was comparable to the conversion of 38.1% and the selectivity of 82.2% achieved by using palladium as the active material.The good stability made this catalyst have good prospects for industrial application.
文摘A combination of tetrachlorosilane（TCS） and phenol in dichloromethane was found to be an efficient reagent for hydro-chlorination ofα,β-unsaturated ketones to afford the correspondingβ-chloroketones in good yield at ambient temperature. Reactions of the titled compounds with TCS-NaN_3 as well as with nitriles utilizing TCS-ZnCl_2 to give 1,5-disubstituted tetrazole derivatives orβ-amido ketones respectively are also described.
基金supported by Natural Science Foundation of China(No,30873153)the Key Projects of Shanghai in Biomedical(No.08431902700)the Scientific Research Foundation of State Education Ministry for the Returned Overseas Chinese Scholars
文摘A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc has been achieved.A series ofα-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization of 2-aryl-1,1-dibromoalkenes.
基金the National Natural Science Foundation of China(Nos.21172057,21272058)the Research Fund for the Doctoral Program of Higher Education(No.20114104110005)forfinancial support
文摘In this paper, an efficient synthesis of cyclopentenyl ketones and cyclohexenyl ketones through tertiary phosphine catalyzed [3 ＋ 2] and [4 ＋ 2] annulations of 1,2-allenic ketones with activated alkenes has been developed. Compared with published synthetic methods on cyclopentenyl ketones and cyclohexenyl ketones, the protocols developed in this paper have the advantages such as readily available starting materials, mild reaction conditions and high efficiency.
基金financially supported by the National Special Fund for State Key Laboratory of Bioreactor Engineering(No.2060204)the National Natural Science Foundation of China(No.20672037)
文摘A reaction of α-bromo aromatic ketones in water with microwave irradiation gave the corresponding α-hydroxy aromatic ketones in good yields. The use of microwaves was found to significantly improve yields and shorten the reaction time. This reaction afforded a very clean, convenient method for the synthesis of α-hydroxy aromatic ketones.
基金Financial support from the Zhejiang Province Natural Science Foundation of China(No.Y4100231)
文摘When ketones were treated with ammonium chloride and Oxone in MeOH at room temperature, a direct or-chlorination of ketones was occurred and a series of the corresponding α-chloroketones were obtained in moderate to good yields after 24 h. In this reaction, ammonium chloride was used as the source of chlorine and Oxone was used as an oxidant. This method was simple, convenient and providing a novel procedure for preparation of α-chloroketones.
基金supported by the National Basic research Program of China (973 Program,2009CB623505)the National Natural Science Foundation of China (21273225)~~
文摘Novel reusable MnOx‐N@C catalyst has been developed for the direct oxidation of N‐heterocycles under solvent‐free conditions using TBHP as benign oxidant to give the corresponding N‐heterocyclic ketones. The catalytic system exhibited a broad substrate scope and excellent regi‐oselectivity, as well as being amenable to gram‐scale synthesis. This MnOx‐N@C catalyst also showed good reusability and was successfully recycled six times without any significant loss of activity.
文摘Ketones smoothly reacted with NBS in the presence of a catalytic amount of ptoluenesulfonic acid to give α-bromoketones in good yields in typical ionic liquids, such as [bmim]PF6 and [bmpy]Tf2N, and the ionic liquids could be repeatedly used for the same reaction after the extraction of the α-bromoketones. Then, the one-pot conversion of ketones into thiazoles by the treatment with NBS, and subsequently with thioamides could be also carried out in [bmim]PF6 and [bmpy]Tf2N, respectively Thus, [bmim]PF6 and [bmpy]Tf2N could be used as recyclable reaction media for the preparation α-bromoketones and thiazoles from ketones.
文摘A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .
基金the financial support from Nanjing University of Science and Technology.
文摘Cerium trichloride heptahydrate(CeCl_3·7H_2O) was found to be an efficient and recyclable catalyst for the three-component direct Mannich reaction of anilines and benzaldehydes with acetophenone.This protocol has advantages of high yield,no environmental pollution,mild condition,and simple work-up procedure.
基金partly financed by the Major State Basic Research Development Program of China(No.2003 CB615700)the National Natural Science Foundation of China(No.20604005).
文摘Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.
基金support and purchase of Hewlett-Packard 6890 GC-Hewlett-Packard 5973N MSD instrument.
文摘The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.
基金support by the Natural Science Foundation of Zhejiang Province(No.Y4051137,Y405015 and Y4080177)
文摘Michael addition of indole and pyrrole to a variety of α, β-unsaturated ketones was efficiently promoted by a catalytic amount of GaCl3 in aqueous media to afford the corresponding products in good to excellent yields.
