A simple copper-promoted one-pot Sandmeyer trifluoromethylation of aromatic amines with Langlois＇ reagent has been demonstrated. The reaction is performed in mild reaction conditions under an air atmosphere with good...A simple copper-promoted one-pot Sandmeyer trifluoromethylation of aromatic amines with Langlois＇ reagent has been demonstrated. The reaction is performed in mild reaction conditions under an air atmosphere with good substrate scope and functional group compatibility. It provides an alternative and straightforward synthetic approach to access a variety of trifluoromethylated arenes.展开更多
Introduction Calixarenes are one of the most important supra- molecular building blocks, which can be modified by introducing different functional and/or structural groups to create a specific interaction between the...Introduction Calixarenes are one of the most important supra- molecular building blocks, which can be modified by introducing different functional and/or structural groups to create a specific interaction between the host and the target molecules, such as metal cations and small organic molecules. In particular, the recognition of amino acids is an interesting theme in biomimetic chemistry.展开更多
An ESZ KTTV instrument of a new,relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes,expressed as spark energy,EES,required for 50-percent initiation pr...An ESZ KTTV instrument of a new,relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes,expressed as spark energy,EES,required for 50-percent initiation probability.The thermal stability thresholds,Tmax,were calculated from the published Arrhenius parameters of monomolecular thermal decomposition of the studied compounds,predominantly obtained under the conditions of the Russian manometric method.An approximate relationship has been found between the ln EES values and threshold Tmax values.In the sense of this relationship,the compounds studied fall into several sub-groups.The reason of the said diversification lies in the decomposition reaction rate at the temperature of onset of their thermal decomposition.It has been found that in each sub-group increasing thermal stability of polynitro arenes is accompanied by increasing electric spark sensitivity of these substances.This fact must be taken into account if we deal with the problem of electric spark energy transfer into the reaction centre of the molecule.展开更多
N-heterocyclic carbene-catalyzed reactions for the formation of aromatic compounds are reviewed.The reactions are subdivided into 4 types based on their activation modes.A brief summary on the achievements and the cha...N-heterocyclic carbene-catalyzed reactions for the formation of aromatic compounds are reviewed.The reactions are subdivided into 4 types based on their activation modes.A brief summary on the achievements and the challenges remaining in Nheterocyclic carbene(NHC)-catalyzed arene construction processes is provided at the end of this review.An outlook into the future research direction within this field is also given based on our own opinion and knowledge on the trends of the development of NHC organocatalysis.展开更多
A Ru-arene compound containing two thiosemicarbazone ligands [(η6-p-cymene)Ru(TSC)2 Cl]Cl(1, TSC = benzophenone 4-methylthiosemicarbazone) has been synthesized and characterized by 1 H NMR, elemental analysis and HR-...A Ru-arene compound containing two thiosemicarbazone ligands [(η6-p-cymene)Ru(TSC)2 Cl]Cl(1, TSC = benzophenone 4-methylthiosemicarbazone) has been synthesized and characterized by 1 H NMR, elemental analysis and HR-ESI mass spectrometry analysis. The molecular structure was determined by single-crystal X-ray diffraction analysis. The in vitro anticancer activities of the complex have been evaluated against two human cancer cell lines(SGC-7901, BEL-7404), and the IC50 values are 32.5 and 57 μM, respectively.展开更多
Chlorospermines A and B are biologically interesting acridone natural products and recently isolated from Glycosmis chlorosperma.We report here a convergent approach to construct the tetracyclic core of the natural pr...Chlorospermines A and B are biologically interesting acridone natural products and recently isolated from Glycosmis chlorosperma.We report here a convergent approach to construct the tetracyclic core of the natural products.The two fragments are assembled together through Sonogashira coupling,and a cis-triene intermediate was prepared by using hydrosilylation/desilylation.A 6p-electrocyclization/aromatization sequence served as the key step of the synthesis,which formed the tetrasubstituted arene motif in one pot.展开更多
Pagoda[5]arene(P5),which is composed of five 2,6-dimethoxylanthracene(2,6-DMA)subunits bridged by methylene groups at 1,5 positions,was conveniently synthesized in 43%by trifluoroacetic acid(TFA)-catalyzed one-pot con...Pagoda[5]arene(P5),which is composed of five 2,6-dimethoxylanthracene(2,6-DMA)subunits bridged by methylene groups at 1,5 positions,was conveniently synthesized in 43%by trifluoroacetic acid(TFA)-catalyzed one-pot condensation of commercially available 2,6-DMA and paraformaldehyde in 1,2-dichlorobenzene(o-DCB)at room temperature.P5 showed a highly symmetrical pentagonal structure with a large and deep electron-rich cavity,which made it form stable 1∶2 host–guest complexes with various aryl-pyridinium,bipyridinium,and stilbazolium salts in solution.Interestingly,P5 could complex two or even three guests with its intrinsic cavity and the pseudocavity formed by the adjacent macrocycles in solid states.Moreover,the strong intermolecular charge-transfer(ICT)interactions between P5 and the guests were observed.Especially,the complexes formed by P5 and the protonated pyridinium or bipyridinium salts showed acid/base-responsive color changes in solution and remarkable crystalline vapochromic properties by two kinds of processes:from ICT to no ICT and from ICT to enhanced ICT interaction or vice versa.We believe that the easily available P5 with the specific structure and intriguing 1∶2 host–guest complexation can find wide application in supramolecular assemblies and functional materials.展开更多
Substituted-benzene-1,2-dicarbaldehydes were synthesized by the reaction of substituted-1,2-bis(dibromomethyl) benzenes with fuming sulfuric acid,followed by hydrolysis. The yields were signifi-cantly improved by intr...Substituted-benzene-1,2-dicarbaldehydes were synthesized by the reaction of substituted-1,2-bis(dibromomethyl) benzenes with fuming sulfuric acid,followed by hydrolysis. The yields were signifi-cantly improved by introducing solid sodium bicarbonate into the reaction mixture before hydrolysis and workup.展开更多
基金We acknowledge the financial support for this work from the National Natural Science Foundation of China （Nos. 21502070 and 21562041） and the Fundamental Research Funds for the Central Universities （No. JUSRP51626B）.
文摘A simple copper-promoted one-pot Sandmeyer trifluoromethylation of aromatic amines with Langlois＇ reagent has been demonstrated. The reaction is performed in mild reaction conditions under an air atmosphere with good substrate scope and functional group compatibility. It provides an alternative and straightforward synthetic approach to access a variety of trifluoromethylated arenes.
基金Project supported by the National Key Research and Development Program of China(No.2022YFA1503200)the National Natural Science Foundation of China(Nos.22371149,22188101)+1 种基金the Fundamental Research Funds for the Central Universities(No.63223015)the Frontiers Science Center for New Organic Matter,Nankai University(No.63181206)。
基金Supported by the National Natural Science Foundation of China(No. 20402002) Natural Science Foundation of FujianProvince, China(Nos. E0220002 and 2006J0155).
文摘Introduction Calixarenes are one of the most important supra- molecular building blocks, which can be modified by introducing different functional and/or structural groups to create a specific interaction between the host and the target molecules, such as metal cations and small organic molecules. In particular, the recognition of amino acids is an interesting theme in biomimetic chemistry.
基金The research was carried out under the auspices of the Ministry of Education,Youth & Sports of the Czech Republic as a part of its research project No.MSM0021627501
文摘An ESZ KTTV instrument of a new,relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes,expressed as spark energy,EES,required for 50-percent initiation probability.The thermal stability thresholds,Tmax,were calculated from the published Arrhenius parameters of monomolecular thermal decomposition of the studied compounds,predominantly obtained under the conditions of the Russian manometric method.An approximate relationship has been found between the ln EES values and threshold Tmax values.In the sense of this relationship,the compounds studied fall into several sub-groups.The reason of the said diversification lies in the decomposition reaction rate at the temperature of onset of their thermal decomposition.It has been found that in each sub-group increasing thermal stability of polynitro arenes is accompanied by increasing electric spark sensitivity of these substances.This fact must be taken into account if we deal with the problem of electric spark energy transfer into the reaction centre of the molecule.
文摘N-heterocyclic carbene-catalyzed reactions for the formation of aromatic compounds are reviewed.The reactions are subdivided into 4 types based on their activation modes.A brief summary on the achievements and the challenges remaining in Nheterocyclic carbene(NHC)-catalyzed arene construction processes is provided at the end of this review.An outlook into the future research direction within this field is also given based on our own opinion and knowledge on the trends of the development of NHC organocatalysis.
基金Supported by the National Natural Science Foundation of China(21761006)Guangxi Natural Science Foundation(2016GXNSFCA380013,2017GXNSFAA198335,2018GXNSFAA281345)+3 种基金Guangxi Scientific and Technological Development Projects(AD17195081),“BAGUI Scholar” Program of Guangxi Province of China,Guangxi Key Laboratory of Natural Polymer Chemistry and Physics and Nanning Normal University,Natural Science Foundation of Guangxi University of Chinese Medicine(2017JQ001)Natural Science Foundation of Team of Professor Shilin Yang(YSL17004)the specific subject of the dominant discipline construction of Chinese pharmacy from Guangxi University of Chinese Medicine(ZYX2017003)Guangxi Key Laboratory of Zhuang and Yao Ethnic Medicine,Collaborative Innovation Center of Zhuang and Yao Ethnic Medicine,Guangxi Key Discipline(Zhuang Pharmacology)
文摘A Ru-arene compound containing two thiosemicarbazone ligands [(η6-p-cymene)Ru(TSC)2 Cl]Cl(1, TSC = benzophenone 4-methylthiosemicarbazone) has been synthesized and characterized by 1 H NMR, elemental analysis and HR-ESI mass spectrometry analysis. The molecular structure was determined by single-crystal X-ray diffraction analysis. The in vitro anticancer activities of the complex have been evaluated against two human cancer cell lines(SGC-7901, BEL-7404), and the IC50 values are 32.5 and 57 μM, respectively.
基金Ministry of Science & Technology (No.2013CB836900)National Natural Science Foundation of China (Nos.21290180,21172235 and 21222202)China Postdoctoral Science Foundation (No.2014M561537,M.Y.)
文摘Chlorospermines A and B are biologically interesting acridone natural products and recently isolated from Glycosmis chlorosperma.We report here a convergent approach to construct the tetracyclic core of the natural products.The two fragments are assembled together through Sonogashira coupling,and a cis-triene intermediate was prepared by using hydrosilylation/desilylation.A 6p-electrocyclization/aromatization sequence served as the key step of the synthesis,which formed the tetrasubstituted arene motif in one pot.
基金The authors thank the National Natural Science Foundation of China(nos.22031010,21772205,21521002,and 91856117)for financial support.
文摘Pagoda[5]arene(P5),which is composed of five 2,6-dimethoxylanthracene(2,6-DMA)subunits bridged by methylene groups at 1,5 positions,was conveniently synthesized in 43%by trifluoroacetic acid(TFA)-catalyzed one-pot condensation of commercially available 2,6-DMA and paraformaldehyde in 1,2-dichlorobenzene(o-DCB)at room temperature.P5 showed a highly symmetrical pentagonal structure with a large and deep electron-rich cavity,which made it form stable 1∶2 host–guest complexes with various aryl-pyridinium,bipyridinium,and stilbazolium salts in solution.Interestingly,P5 could complex two or even three guests with its intrinsic cavity and the pseudocavity formed by the adjacent macrocycles in solid states.Moreover,the strong intermolecular charge-transfer(ICT)interactions between P5 and the guests were observed.Especially,the complexes formed by P5 and the protonated pyridinium or bipyridinium salts showed acid/base-responsive color changes in solution and remarkable crystalline vapochromic properties by two kinds of processes:from ICT to no ICT and from ICT to enhanced ICT interaction or vice versa.We believe that the easily available P5 with the specific structure and intriguing 1∶2 host–guest complexation can find wide application in supramolecular assemblies and functional materials.
文摘Substituted-benzene-1,2-dicarbaldehydes were synthesized by the reaction of substituted-1,2-bis(dibromomethyl) benzenes with fuming sulfuric acid,followed by hydrolysis. The yields were signifi-cantly improved by introducing solid sodium bicarbonate into the reaction mixture before hydrolysis and workup.
基金Project supported by the National Natural Science Foundation of China(No.21801018)the Beijing Institute of Technology Research Fund Program for Young Scholars(No.1230011181807)~~
