Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great signif...Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.展开更多
Our work reported that the so-called pure carbon nanotubes(CNTs)can be synthesized without metallic catalyst by chemical vapor deposition(CVD).The as-prepared CNTs have average diameter of 50 nm and length over severa...Our work reported that the so-called pure carbon nanotubes(CNTs)can be synthesized without metallic catalyst by chemical vapor deposition(CVD).The as-prepared CNTs have average diameter of 50 nm and length over several microns.Analysis of intermediate objects in the products indicates that their formation mechanism follows the wire-to-tube model.Besides,according to thermodynamic analysis of the driving force combing with experimental results,we find that the thermal gradient can effectively favor the formation of CNTs in our metallic catalyst-free CVD.展开更多
The copper-catalyzed and metal-free azide-alkyne click polymerizations have become efficient tools for polymer synthesis. However,the 1,3-dipolar polycycloadditions between internal alkynes and azides are rarely emplo...The copper-catalyzed and metal-free azide-alkyne click polymerizations have become efficient tools for polymer synthesis. However,the 1,3-dipolar polycycloadditions between internal alkynes and azides are rarely employed to construct functional polymers. Herein, the polycycloadditions of dibutynoate(1) and tetraphenylethene-containing diazides(2) were carried out at 100 °C for 12 h under solvent-and catalyst-free conditions, producing soluble poly(methyltriazolylcarboxylate)s(PMTCs) with high molecular weights in high yields. The resultant polymers were thermally stable with 5% weight loss temperatures up to 377 °C. The PMTCs showed aggregation-induced emission(AIE)properties. They could work as fluorescent sensors for detecting explosive with high sensitivity, and generate two-dimensional fluorescent photopatterns with high resolution. Furthermore, their triazolium salts could be utilized for cell-imaging applications.展开更多
A series of new photodegradable poly(furan-amine)s(PFAs) were synthesized by a one-pot, catalyst-free, multicomponent cyclopolymerization between diisocyanides, dialkylacetylene dicarboxylates, and aromatic dialdehyde...A series of new photodegradable poly(furan-amine)s(PFAs) were synthesized by a one-pot, catalyst-free, multicomponent cyclopolymerization between diisocyanides, dialkylacetylene dicarboxylates, and aromatic dialdehydes. All polymerizations were conducted in toluene at 100 ℃ for 6 h without inert gas protection and furnished polymers with a satisfactory molecular weight(Mw up to32200) and yield. The PFA structure was confirmed by spectroscopic techniques, such as GPC, FTIR, and NMR, as well as by comparison with a model compound. The polymers exhibited good solubility in common organic solvents and thermal stability. All the PFAs had high refractive indices in the visible light region(400 nm to 800 nm). Moreover, the PFAs were substantially degraded by UV irradiation due to the presence of furan rings. The film thickness reduction rate could be over 90%.展开更多
The tandem reaction of photoinduced double hydrogen-atom transfer and deoxygenative transborylation for chemo-and site-selective reduction of nitroarenes into aryl amines under catalyst-free, room temperature conditio...The tandem reaction of photoinduced double hydrogen-atom transfer and deoxygenative transborylation for chemo-and site-selective reduction of nitroarenes into aryl amines under catalyst-free, room temperature conditions was disclosed in excellent yields. In this reaction, isopropanol(^(i)PrOH) was used as hydrogen donor and tetrahydroxydiboron [B_(2)(OH)_(4)] as deoxygenative reagent with green, cheap, and commercially available credentials. In particular, a wide range of reducible functional groups such as halogen(-Cl,-Br and even-I), alkenyl, alkynyl, aldehyde, ketone, carboxyl, and cyano are all tolerated. Moreover,the reaction preferentially reduces the nitro group at the electron-deficient site over another nitro group in the same molecule. A detailed mechanistic investigation in combination of experiments and theoretical calculations gave a reasonable explanation for the reaction pathway.展开更多
Oxidation of petroleum-based byproduct dicyclopentadiene derived diformyltricyclodecanes(DFTD) to dicarboxyltriclodecanesacids(DCTDA) was conducted under catalyst-free and ultra-low temperature conditions with O2 as o...Oxidation of petroleum-based byproduct dicyclopentadiene derived diformyltricyclodecanes(DFTD) to dicarboxyltriclodecanesacids(DCTDA) was conducted under catalyst-free and ultra-low temperature conditions with O2 as oxidant. In the perspective of industry process, oxygen pressure and contents, solvent and raw material initial concentrations were screened to evaluate their influence on DCTDA generation. Results indicate that DFTD oxidation can occur rather easily under no-catalyst and ultra-low temperature conditions with O2 as oxidant. Oxygen content and pressure had positive effect on DCTDA production, γ-valerolactone(GVL) behaved best on DFTD generation in dynamics, while methanol could be used as a protective solvent to preserve DFTD.Besides, the existence of water in solvent was not beneficial to DCTDA production because of poor DFTD compatibility with water. The mechanisms of O2 and solvent influence on DCTDA generation were discussed. Meanwhile,the oxidation route of DFTD–Intermediate–DCTDA was proposed. The present work exhibits the valued potential of DFTD, which will have a positive effect on high added value of petroleum based by-products.展开更多
A facile procedure for the synthesis, of quinoxalines is being reported starting from benzil and 1,2-diaminobenzene. The reactions were carried out catalyst-free, solvent-free and under microwave irradiation condition...A facile procedure for the synthesis, of quinoxalines is being reported starting from benzil and 1,2-diaminobenzene. The reactions were carried out catalyst-free, solvent-free and under microwave irradiation conditions in high yield （84-98%） with short time （3-6 min） and environmental benign, as well as convenient operation. The structures of all the compounds have been confirmed on the basis of their IR, 1H NMR, and/or 13C NMR, mass spectral data.展开更多
A facile procedure for the synthesis of 2,4,5-lriarylimidazoles is being reported starting from benzil, aromatic aldehyde and ammonium acetate. The reactions were carried out with catalyst-free, solvent-free and under...A facile procedure for the synthesis of 2,4,5-lriarylimidazoles is being reported starting from benzil, aromatic aldehyde and ammonium acetate. The reactions were carried out with catalyst-free, solvent-free and under microwave irradiation conditions in high yield （80-99%） with short time （3-5 min） and environmental benign, as well as convenient operation. The structures of the compounds have been confirmed on the basis of their IR, 1H NMR, and/or 13C NMR, MS, and elemental analyzer.展开更多
4-Methylene-1,3-oxazolidin-2-ones can be synthesized from propargylic alcohols, primary amines and carbon dioxide under supercritical condition in the absence of any additional catalyst and solvent. Various propargyli...4-Methylene-1,3-oxazolidin-2-ones can be synthesized from propargylic alcohols, primary amines and carbon dioxide under supercritical condition in the absence of any additional catalyst and solvent. Various propargylic alcohols and primary amines were examined.展开更多
An expedient and mild strategy for the synthesis of unconventional 2-（dimethylamino）-3,3-difluorochroman-4-one derivatives from o-hydroxyarylenaminones and Selectfluor was developed at room temperature under catalys...An expedient and mild strategy for the synthesis of unconventional 2-（dimethylamino）-3,3-difluorochroman-4-one derivatives from o-hydroxyarylenaminones and Selectfluor was developed at room temperature under catalyst-free conditions. This method showed excellent chemoselectivity and great functional groups tolerance.展开更多
The first HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones(27 examples,up to 98% yield) from readily available indoles and isatin derivatives are d...The first HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones(27 examples,up to 98% yield) from readily available indoles and isatin derivatives are described.This protocol shows well tolerance of different functional groups and features mild reaction conditions such as short reaction time(~1 h),no usage of catalyst,easy operation and product isolation.Of particular intere st is the formation of two C-C bonds and one all-carbon quaternary center.This protocol could serve as an alternative strategy to synthesize biologically important 3,3-di(indolyl)indolin-2-ones for biological testing.展开更多
In the field of organic syntheses, the development of environmentally friendly methods based on the concept of green chemistry has been always required. In response to this requirement, we reported solvent- and cataly...In the field of organic syntheses, the development of environmentally friendly methods based on the concept of green chemistry has been always required. In response to this requirement, we reported solvent- and catalyst-free syntheses of imines using the pressure reduction technique as a key technology. We found that this reaction proceeded very rapidly in the initial stage, but its rate decreased with the passage of time. It was also found that the reaction of benzaldehyde with aniline had a specificity that the phase transition occurred. In this method, the desired imines could be obtained in good to excellent yields, but target compounds had to be given by purifications using organic solvents. Therefore, we tried to develop the perfect synthetic method of imine derivatives without organic or inorganic solvents. We selected two methods and took them into this investigation. One was exactly mixing (1:1, substance ratio) aldehydes and amines and the other was employing lower pressure (>0.1 mmHg, previous method: 1.0 mmHg) at the pressure reducing technique. When this improved synthetic method was performed, it was revealed that pure target imines were obtained in excellent yields without any purification.展开更多
Because imines could be used as convenient starting materials in various fields, the development of an easy synthetic method of imine was strongly desired. In response to this demand, we thought that it would be an ef...Because imines could be used as convenient starting materials in various fields, the development of an easy synthetic method of imine was strongly desired. In response to this demand, we thought that it would be an effective synthesis method if an aldehyde and an amine could be reacted to give an imine in good yield under solvent- and catalyst-free conditions. In fact, we tried the reaction of benzaldehyde with various amines under solvent- and catalyst-free conditions followed by removal of water that was produced in the reaction system by a vacuum pump, and desired imines could be obtained in good yields. Observation of this reaction using a nuclear magnetic resonance spectrometer revealed that the reaction rate was extremely fast at the initial stage but slowed over time. However, the reaction of benzaldehyde with aniline differed greatly, and the reaction rate dramatically improved in 47 - 48 minutes after the start of the reaction. At this time, we found that the reaction system underwent a phase transition from the liquid phase to the solid phase.展开更多
It has been found that microwave assisted decarboxylation of malonic acid derivatives can be achieved under solvent-free and catalyst free conditions. This new method produces the corresponding carboxylic acid in a pu...It has been found that microwave assisted decarboxylation of malonic acid derivatives can be achieved under solvent-free and catalyst free conditions. This new method produces the corresponding carboxylic acid in a pure manner and with a high yield in a very short reaction time: 3 - 10 min. In general terms, the condition under which this reaction is carried out accelerates the decarboxylation significantly of a series of disubstituted malonic acid derivatives, and makes this new process efficient, easy and environmentally friendly.展开更多
We present a simple and straightforward protocol for hydrochlorination of terminal arylalkynes to vinyl chlorides using hydrogen chloride under mild reaction conditions. This protocol does not involve any metal cataly...We present a simple and straightforward protocol for hydrochlorination of terminal arylalkynes to vinyl chlorides using hydrogen chloride under mild reaction conditions. This protocol does not involve any metal catalysts or additives. It is simple, inexpensive, and easy to prepare, and exhibits good reaction activity. The hydrochlorination proceeds smoothly to yield unique regioselective products via the Markovnikov addition rule.展开更多
Fifteen dihydropyrimidinthiones have been synthesized by microwave-assisted Biginelli reactions without any solvent or catalyst. The advantages of this novel protocol include the excellent yield, operational simplicit...Fifteen dihydropyrimidinthiones have been synthesized by microwave-assisted Biginelli reactions without any solvent or catalyst. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of organic solvents and catalysts.展开更多
The pursuit of sustainable and environmentally benign synthetic methods continues to challenge organic chemists. Herein, we introduce a magnetoredox system for tri- and difluoromethylation of isocyanides and N-arylacr...The pursuit of sustainable and environmentally benign synthetic methods continues to challenge organic chemists. Herein, we introduce a magnetoredox system for tri- and difluoromethylation of isocyanides and N-arylacrylamides using a rotating magnetic field and steel rods. This magnetoredox approach enables facile synthesis of functionalized phenanthridines and oxindoles without the need for catalysts and additives under mild conditions. Such a system potentially represents an attractive strategy for selective formation of bonds through multifaceted regulation of magnetic intensity, rotating frequency, and rod size.展开更多
Herein,an electrochemically driven catalyst-free nucleophilic aromatic substitution(S_(N)Ar)of electron-rich fluoroarenes with carboxylic acids as weak nucleophiles under mild conditions was reported.A series of highl...Herein,an electrochemically driven catalyst-free nucleophilic aromatic substitution(S_(N)Ar)of electron-rich fluoroarenes with carboxylic acids as weak nucleophiles under mild conditions was reported.A series of highly valuable ester derivatives were obtained in a direct and rapid way.This transformation features commercially available reagents and an exceptionally broad substrate scope with good functional group tolerance,using cheap and abundant electrodes and completed within a short reaction time.Gram-scale synthesis and complex biorelevant compounds ligation further highlighted the potential utility of the methodology.The mechanistic investigations and density functional theory(DFT)calculations verified the feasibility of the proposed pathway of this transformation.展开更多
A catalyst-free and atom-economical[4+3]cycloaddition of azadienes with C,N-cyclic azomethine imines has been developed,providing an efficient and environmentally benign access to 1,2,4-triazepines with high diastereo...A catalyst-free and atom-economical[4+3]cycloaddition of azadienes with C,N-cyclic azomethine imines has been developed,providing an efficient and environmentally benign access to 1,2,4-triazepines with high diastereoselectivities and yields.This reaction can be performed in 2-methyltetrahydrofuran under mild conditions smoothly.展开更多
We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote ...We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition （r-PECVD） system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy （STM） confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp2 carbon atoms being formed in the case of graphene rather than sp3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalable, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films.展开更多
基金financially supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22001078).
文摘Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.
基金supported by the Creative Research Group of National Science Foundation of China(Grant No.50721003)the Foundation of the Ministry of Education of China for Returned Scholars(Grant No.2005383)
文摘Our work reported that the so-called pure carbon nanotubes(CNTs)can be synthesized without metallic catalyst by chemical vapor deposition(CVD).The as-prepared CNTs have average diameter of 50 nm and length over several microns.Analysis of intermediate objects in the products indicates that their formation mechanism follows the wire-to-tube model.Besides,according to thermodynamic analysis of the driving force combing with experimental results,we find that the thermal gradient can effectively favor the formation of CNTs in our metallic catalyst-free CVD.
基金partially supported by the National Natural Science Foundation of China (Nos. 21875152 and 21404077)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No. 17KJB150034)+2 种基金the Priority Academic Program Development of Jiangsu High Education Institutions (PAPD)the financial supports from Jiangsu Planned Projects for Postdoctoral Research Funds (No. 1501023B)China Postdoctoral Science Foundation (No. 2016M591906)
文摘The copper-catalyzed and metal-free azide-alkyne click polymerizations have become efficient tools for polymer synthesis. However,the 1,3-dipolar polycycloadditions between internal alkynes and azides are rarely employed to construct functional polymers. Herein, the polycycloadditions of dibutynoate(1) and tetraphenylethene-containing diazides(2) were carried out at 100 °C for 12 h under solvent-and catalyst-free conditions, producing soluble poly(methyltriazolylcarboxylate)s(PMTCs) with high molecular weights in high yields. The resultant polymers were thermally stable with 5% weight loss temperatures up to 377 °C. The PMTCs showed aggregation-induced emission(AIE)properties. They could work as fluorescent sensors for detecting explosive with high sensitivity, and generate two-dimensional fluorescent photopatterns with high resolution. Furthermore, their triazolium salts could be utilized for cell-imaging applications.
基金financially supported by the National Natural Science Foundation of China (Nos. 21490574, 21875019, 51673024, and 51803009)Beijing Institute of Technology Research Fund Program for Young Scholars
文摘A series of new photodegradable poly(furan-amine)s(PFAs) were synthesized by a one-pot, catalyst-free, multicomponent cyclopolymerization between diisocyanides, dialkylacetylene dicarboxylates, and aromatic dialdehydes. All polymerizations were conducted in toluene at 100 ℃ for 6 h without inert gas protection and furnished polymers with a satisfactory molecular weight(Mw up to32200) and yield. The PFA structure was confirmed by spectroscopic techniques, such as GPC, FTIR, and NMR, as well as by comparison with a model compound. The polymers exhibited good solubility in common organic solvents and thermal stability. All the PFAs had high refractive indices in the visible light region(400 nm to 800 nm). Moreover, the PFAs were substantially degraded by UV irradiation due to the presence of furan rings. The film thickness reduction rate could be over 90%.
基金financial support from the National Natural Science Foundation of China (Nos. 21820102004, 91961104, 21803030, 21875104, and 51673095)Program B for outstanding Ph.D. candidates of Nanjing University+2 种基金the Fundamental Research Funds for the Central Universities (No. 020514380253)the Natural Science Foundation of Jiangsu Province (No. BK20211555)the Jiangsu Innovation and Entrepreneurship Talents Plan
文摘The tandem reaction of photoinduced double hydrogen-atom transfer and deoxygenative transborylation for chemo-and site-selective reduction of nitroarenes into aryl amines under catalyst-free, room temperature conditions was disclosed in excellent yields. In this reaction, isopropanol(^(i)PrOH) was used as hydrogen donor and tetrahydroxydiboron [B_(2)(OH)_(4)] as deoxygenative reagent with green, cheap, and commercially available credentials. In particular, a wide range of reducible functional groups such as halogen(-Cl,-Br and even-I), alkenyl, alkynyl, aldehyde, ketone, carboxyl, and cyano are all tolerated. Moreover,the reaction preferentially reduces the nitro group at the electron-deficient site over another nitro group in the same molecule. A detailed mechanistic investigation in combination of experiments and theoretical calculations gave a reasonable explanation for the reaction pathway.
基金Supported by the Research Foundation of China University of Petroleum,-Beijing at Karamay(YJ2018B02006)the Chinese Government “Thousand Talent” Program(Y42H291501).
文摘Oxidation of petroleum-based byproduct dicyclopentadiene derived diformyltricyclodecanes(DFTD) to dicarboxyltriclodecanesacids(DCTDA) was conducted under catalyst-free and ultra-low temperature conditions with O2 as oxidant. In the perspective of industry process, oxygen pressure and contents, solvent and raw material initial concentrations were screened to evaluate their influence on DCTDA generation. Results indicate that DFTD oxidation can occur rather easily under no-catalyst and ultra-low temperature conditions with O2 as oxidant. Oxygen content and pressure had positive effect on DCTDA production, γ-valerolactone(GVL) behaved best on DFTD generation in dynamics, while methanol could be used as a protective solvent to preserve DFTD.Besides, the existence of water in solvent was not beneficial to DCTDA production because of poor DFTD compatibility with water. The mechanisms of O2 and solvent influence on DCTDA generation were discussed. Meanwhile,the oxidation route of DFTD–Intermediate–DCTDA was proposed. The present work exhibits the valued potential of DFTD, which will have a positive effect on high added value of petroleum based by-products.
基金Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials for financial support(No.JSKC07041)
文摘A facile procedure for the synthesis, of quinoxalines is being reported starting from benzil and 1,2-diaminobenzene. The reactions were carried out catalyst-free, solvent-free and under microwave irradiation conditions in high yield （84-98%） with short time （3-6 min） and environmental benign, as well as convenient operation. The structures of all the compounds have been confirmed on the basis of their IR, 1H NMR, and/or 13C NMR, mass spectral data.
基金the Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials for financial support(No. JSKC07041)
文摘A facile procedure for the synthesis of 2,4,5-lriarylimidazoles is being reported starting from benzil, aromatic aldehyde and ammonium acetate. The reactions were carried out with catalyst-free, solvent-free and under microwave irradiation conditions in high yield （80-99%） with short time （3-5 min） and environmental benign, as well as convenient operation. The structures of the compounds have been confirmed on the basis of their IR, 1H NMR, and/or 13C NMR, MS, and elemental analyzer.
基金supported financially by Youth Foundation of Guangdong Medical College(No.XQ1029)Science and Technology Planning Project of Zhanjiang city(No.2009c3103024)
文摘4-Methylene-1,3-oxazolidin-2-ones can be synthesized from propargylic alcohols, primary amines and carbon dioxide under supercritical condition in the absence of any additional catalyst and solvent. Various propargylic alcohols and primary amines were examined.
基金Financial support from the Recruitment Program of Global Experts (1000 Talents Plan)the Natural Science Foundation of Fujian Province (No. 2016J01064)+1 种基金Fujian Hundred Talents Plan, Program of Innovative Research Team of Huaqiao University (No. Z14X0047)Subsidized Project for Cultivating Postgraduates’ Innovative Ability in Scientific Research of Huaqiao University (for Z. Kuang) are gratefully acknowledged
文摘An expedient and mild strategy for the synthesis of unconventional 2-（dimethylamino）-3,3-difluorochroman-4-one derivatives from o-hydroxyarylenaminones and Selectfluor was developed at room temperature under catalyst-free conditions. This method showed excellent chemoselectivity and great functional groups tolerance.
基金supported by the National Natural Science Foundation of China(Nos.81773562,81703326 and 81973177)The Open Project of State Key Laboratory of Natural Medicines(No.SKLNMKF202005)China Postdoctoral Science Foundation(Nos.2018M630840 and 2019T120641)。
文摘The first HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones(27 examples,up to 98% yield) from readily available indoles and isatin derivatives are described.This protocol shows well tolerance of different functional groups and features mild reaction conditions such as short reaction time(~1 h),no usage of catalyst,easy operation and product isolation.Of particular intere st is the formation of two C-C bonds and one all-carbon quaternary center.This protocol could serve as an alternative strategy to synthesize biologically important 3,3-di(indolyl)indolin-2-ones for biological testing.
文摘In the field of organic syntheses, the development of environmentally friendly methods based on the concept of green chemistry has been always required. In response to this requirement, we reported solvent- and catalyst-free syntheses of imines using the pressure reduction technique as a key technology. We found that this reaction proceeded very rapidly in the initial stage, but its rate decreased with the passage of time. It was also found that the reaction of benzaldehyde with aniline had a specificity that the phase transition occurred. In this method, the desired imines could be obtained in good to excellent yields, but target compounds had to be given by purifications using organic solvents. Therefore, we tried to develop the perfect synthetic method of imine derivatives without organic or inorganic solvents. We selected two methods and took them into this investigation. One was exactly mixing (1:1, substance ratio) aldehydes and amines and the other was employing lower pressure (>0.1 mmHg, previous method: 1.0 mmHg) at the pressure reducing technique. When this improved synthetic method was performed, it was revealed that pure target imines were obtained in excellent yields without any purification.
文摘Because imines could be used as convenient starting materials in various fields, the development of an easy synthetic method of imine was strongly desired. In response to this demand, we thought that it would be an effective synthesis method if an aldehyde and an amine could be reacted to give an imine in good yield under solvent- and catalyst-free conditions. In fact, we tried the reaction of benzaldehyde with various amines under solvent- and catalyst-free conditions followed by removal of water that was produced in the reaction system by a vacuum pump, and desired imines could be obtained in good yields. Observation of this reaction using a nuclear magnetic resonance spectrometer revealed that the reaction rate was extremely fast at the initial stage but slowed over time. However, the reaction of benzaldehyde with aniline differed greatly, and the reaction rate dramatically improved in 47 - 48 minutes after the start of the reaction. At this time, we found that the reaction system underwent a phase transition from the liquid phase to the solid phase.
文摘It has been found that microwave assisted decarboxylation of malonic acid derivatives can be achieved under solvent-free and catalyst free conditions. This new method produces the corresponding carboxylic acid in a pure manner and with a high yield in a very short reaction time: 3 - 10 min. In general terms, the condition under which this reaction is carried out accelerates the decarboxylation significantly of a series of disubstituted malonic acid derivatives, and makes this new process efficient, easy and environmentally friendly.
基金financial support from the National Basic Research Program of China(973 Program,No.2012CB720300)the Applied Basic Research Program of Bingtuan(No.2015AG001)the High-level Talent Scientific Research Project of Shihezi University(No.RCZX201405)
文摘We present a simple and straightforward protocol for hydrochlorination of terminal arylalkynes to vinyl chlorides using hydrogen chloride under mild reaction conditions. This protocol does not involve any metal catalysts or additives. It is simple, inexpensive, and easy to prepare, and exhibits good reaction activity. The hydrochlorination proceeds smoothly to yield unique regioselective products via the Markovnikov addition rule.
基金the Natural Science Foundation of China(No.20272047,20572086)the Natural Science Foundation of Gansu Province(No.3ZS051-A25-001)Key Laboratory of Eco-Environment-Related Polymer Material(Northwest Normal University),Ministry of Education of China.
文摘Fifteen dihydropyrimidinthiones have been synthesized by microwave-assisted Biginelli reactions without any solvent or catalyst. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of organic solvents and catalysts.
基金support by the National Natural Science Foundation of China(22101157)is gratefully acknowledgedWe are very grateful to Prof.Xiao Shen(Wuhan University,China)for helpful discussion.
文摘The pursuit of sustainable and environmentally benign synthetic methods continues to challenge organic chemists. Herein, we introduce a magnetoredox system for tri- and difluoromethylation of isocyanides and N-arylacrylamides using a rotating magnetic field and steel rods. This magnetoredox approach enables facile synthesis of functionalized phenanthridines and oxindoles without the need for catalysts and additives under mild conditions. Such a system potentially represents an attractive strategy for selective formation of bonds through multifaceted regulation of magnetic intensity, rotating frequency, and rod size.
基金Financial support from National Key R&D Program of China(2022YFA1503200)National Natural Science Foundation of China(Grant No.22371149,22188101)+2 种基金the Fundamental Research Funds for the Central Universities(No.63223015)Frontiers Science Center for New Organic Matter,Nankai University(Grant No.63181206)Nankai University are gratefully acknowledged.
文摘Herein,an electrochemically driven catalyst-free nucleophilic aromatic substitution(S_(N)Ar)of electron-rich fluoroarenes with carboxylic acids as weak nucleophiles under mild conditions was reported.A series of highly valuable ester derivatives were obtained in a direct and rapid way.This transformation features commercially available reagents and an exceptionally broad substrate scope with good functional group tolerance,using cheap and abundant electrodes and completed within a short reaction time.Gram-scale synthesis and complex biorelevant compounds ligation further highlighted the potential utility of the methodology.The mechanistic investigations and density functional theory(DFT)calculations verified the feasibility of the proposed pathway of this transformation.
基金We thank the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(QNLM)(No.2022QNLM030003-2)the Fundamental Research Funds for the Central Universities,Ocean University of China,Qingdao National Laboratory for Marine Science and Technology(Nos.LMDBCXRC201902 and LMDBCXRC201903)+2 种基金Taishan Scholar Program of Shandong Province(Nos.tsqn201909056 and tsqn202103152)National Natural Science Foundation of China(No.22171251)Natural Science Foundation of Shandong Province(No.ZR2021QB033)for financial support.
文摘A catalyst-free and atom-economical[4+3]cycloaddition of azadienes with C,N-cyclic azomethine imines has been developed,providing an efficient and environmentally benign access to 1,2,4-triazepines with high diastereoselectivities and yields.This reaction can be performed in 2-methyltetrahydrofuran under mild conditions smoothly.
基金This work was supported by the Institute of Physics Start-up Founding, 100 Talents Program of the Chinese Academy of Sciences （CAS）, the Science Foundation of CAS, the National Science Foundation of China （NSFC） （grant Nos. 10974226 and 11074288）, and the National 973 project of China （grant No. 2010CB934202）.
文摘We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition （r-PECVD） system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy （STM） confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp2 carbon atoms being formed in the case of graphene rather than sp3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalable, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films.
