A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coeffici...A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coefficient was 0.9805, and the standard deviation was only 672.27 cm^-1. The results imply that the excited-state substituent constant can be used productively for research on UV energy of 1,4-disubstituted benzenes. The present method provides a new avenue to study the UV absorption spectra of aromatic systems with the excited-state substituent constant, and it is helpful to understand the effect of substituent electrostatic effects on the chemical and physical properties of conjugated compounds with multiple substituents in excited state.展开更多
A highly efficient method for the synthesis of unsymmetrical multi-substituted 1,2,3-triazoles via a direct Pd-NHC system catalyzed C（5）-arylation of 1,4-disubstituted triazoles, which are readily accessible via ＂c...A highly efficient method for the synthesis of unsymmetrical multi-substituted 1,2,3-triazoles via a direct Pd-NHC system catalyzed C（5）-arylation of 1,4-disubstituted triazoles, which are readily accessible via ＂click＂ chemistry has been developed. It is important to note that C--H bond functionalizations of 1,2,3-triazoles with a variety of differently substituted aryl iodides and bromides as electrophiles can be conveniently achieved through this catalytic system at significantly milder reaction temperatures of 100 ℃ under air.展开更多
A facile synthesis of 1,4-disubstituted 1,2,3-triazoles was achieved from nitrobenzenes and terminal alkynes under mild conditions. The reactions were successful for nitrobenzenes and terminal alkynes bearing various ...A facile synthesis of 1,4-disubstituted 1,2,3-triazoles was achieved from nitrobenzenes and terminal alkynes under mild conditions. The reactions were successful for nitrobenzenes and terminal alkynes bearing various functionalities, from which the 1,2,3-triazole derivatives were smoothly synthesized through a four-step one-pot sequence.展开更多
According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-（halo-2-hydroxyphenyl）imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C ...According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-（halo-2-hydroxyphenyl）imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C NMR, elemental analysis and IR. All the target compounds were screened for their antibacterial potential in vitro against Monilia albican, Escherichia coli and Staphylococcus aureus. It was shown that all the compounds possessed efficient antibacterial activities at a concentration of 0.1 mg/mL, even at a concentration of 0.01 mg/mL, some of the compounds still exhibited antibacterial activities against Escherichia coli and Monilia albican. At last, the struc- ture-activity relationship was discussed based on the antibacterial results.展开更多
Allylalumination of alkynes （i.e. forming Negishi＇s （Z）-alkenyl dialkylalane） followed by alkenylation of epoxides provides 1,4-disubstituted （Z）-3,6-alkadienols. The alkenylation can be facilitated by the pres...Allylalumination of alkynes （i.e. forming Negishi＇s （Z）-alkenyl dialkylalane） followed by alkenylation of epoxides provides 1,4-disubstituted （Z）-3,6-alkadienols. The alkenylation can be facilitated by the presence of a neighbouring coordinating group in the epoxides. This ＂one-pot＂ approach has been successfully applied in the large-scale production of C 10--C 15 fragment of 9,10-didehydroepothilone D （a synthetic epothilone analog as an anti-cancer agent in phase 2 clinical trials）.展开更多
A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides...A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3,4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3,4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.展开更多
Three kinds of products have been separated from the reaction mixtures of 1,2-dihydro-2, 4-disubstituted-1,5-benzodiazepine with: CCI_2.Besides the addition products of: CCI_2 to C=N.the inserted products of: CCI_2 to...Three kinds of products have been separated from the reaction mixtures of 1,2-dihydro-2, 4-disubstituted-1,5-benzodiazepine with: CCI_2.Besides the addition products of: CCI_2 to C=N.the inserted products of: CCI_2 to N-H and C-H single bonds were obtained, too.展开更多
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20772028 and No.20472019）, the Natural Science Foundation of Hunan Province （No.06JJ2002）, and the Scientific Research Fund of Hunan Provincial Education Commission.
文摘A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coefficient was 0.9805, and the standard deviation was only 672.27 cm^-1. The results imply that the excited-state substituent constant can be used productively for research on UV energy of 1,4-disubstituted benzenes. The present method provides a new avenue to study the UV absorption spectra of aromatic systems with the excited-state substituent constant, and it is helpful to understand the effect of substituent electrostatic effects on the chemical and physical properties of conjugated compounds with multiple substituents in excited state.
文摘A highly efficient method for the synthesis of unsymmetrical multi-substituted 1,2,3-triazoles via a direct Pd-NHC system catalyzed C（5）-arylation of 1,4-disubstituted triazoles, which are readily accessible via ＂click＂ chemistry has been developed. It is important to note that C--H bond functionalizations of 1,2,3-triazoles with a variety of differently substituted aryl iodides and bromides as electrophiles can be conveniently achieved through this catalytic system at significantly milder reaction temperatures of 100 ℃ under air.
基金the National Natural Science Foundation of China (Nos. 21262020 and 51464021)the Science and Technology Planning Project of Yunnan Province (No. KKSY201207140) for the financial support
文摘A facile synthesis of 1,4-disubstituted 1,2,3-triazoles was achieved from nitrobenzenes and terminal alkynes under mild conditions. The reactions were successful for nitrobenzenes and terminal alkynes bearing various functionalities, from which the 1,2,3-triazole derivatives were smoothly synthesized through a four-step one-pot sequence.
基金Supported by the National Natural Science Foundation of China(Nos.20976135,21176194)
文摘According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-（halo-2-hydroxyphenyl）imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C NMR, elemental analysis and IR. All the target compounds were screened for their antibacterial potential in vitro against Monilia albican, Escherichia coli and Staphylococcus aureus. It was shown that all the compounds possessed efficient antibacterial activities at a concentration of 0.1 mg/mL, even at a concentration of 0.01 mg/mL, some of the compounds still exhibited antibacterial activities against Escherichia coli and Monilia albican. At last, the struc- ture-activity relationship was discussed based on the antibacterial results.
基金the National Natural Science Foundation of China (NSFC)，Fok Ying Tong Education Foundation
文摘Allylalumination of alkynes （i.e. forming Negishi＇s （Z）-alkenyl dialkylalane） followed by alkenylation of epoxides provides 1,4-disubstituted （Z）-3,6-alkadienols. The alkenylation can be facilitated by the presence of a neighbouring coordinating group in the epoxides. This ＂one-pot＂ approach has been successfully applied in the large-scale production of C 10--C 15 fragment of 9,10-didehydroepothilone D （a synthetic epothilone analog as an anti-cancer agent in phase 2 clinical trials）.
基金financially supported by the National Natural Science Foundation of China (Nos. 22001034 and 21804019)the Open Fund of the Jiangxi Province Key Laboratory of Synthetic Chemistry (No. JXSC202008)the Research Found of East China University of Technology (Nos. DHBK2019264, DHBK2019265 and DHBK2019267)。
文摘A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3,4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3,4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.
文摘Three kinds of products have been separated from the reaction mixtures of 1,2-dihydro-2, 4-disubstituted-1,5-benzodiazepine with: CCI_2.Besides the addition products of: CCI_2 to C=N.the inserted products of: CCI_2 to N-H and C-H single bonds were obtained, too.
