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
A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reag...A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reagent in good to excellent yields.This methodology features mild reaction conditions and good functional group tolerance,providing a direct approach for the preparation of 1 Hpvrazoles.展开更多
In this study,a sandwich-type uranium(Ⅵ)-containing silicotungstate KNa11H2(H2O)30[Na(UO2)(SiW9O34)]2·8H2O(1)with new three-dimensional(3D)structure was synthesized and characterized using single-crystal X-ray d...In this study,a sandwich-type uranium(Ⅵ)-containing silicotungstate KNa11H2(H2O)30[Na(UO2)(SiW9O34)]2·8H2O(1)with new three-dimensional(3D)structure was synthesized and characterized using single-crystal X-ray diffraction,Fourier transform infrared,Raman,solid-state ultraviolet–visible diffuse reflection spectra,thermogravimetric analysis and powder X-ray diffraction.Single crystal analysis revealed that the Na(I)-H2O clusters in 1 showed a two-dimensional structure similar to(4,4)-network and resulted in the formation of a new 3D structure of 1.In addition,it was notable that 1 presented excellent catalytic activity for the synthesis of substituted phenylsulfonyl-1H-pyrazoles via the cyclization reaction of 1,3-diketones with various substituted benzenesulfonyl hydrazides.展开更多
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.
基金financial support for this research from Shandong Provincial Natural Science Foundation(No.ZR2017LB006)Academic promotion programme of Shandong First Medical University(No.2019LJ003)。
文摘A novel route for tandem C-C/C-N formation,annulation and aromatization of hydrazones with 1,2-dichloroethane to synthesize 1 H-pyrazoles has been developed.Furthermore,the 1,2-dichloroethane serves as alkylation reagent in good to excellent yields.This methodology features mild reaction conditions and good functional group tolerance,providing a direct approach for the preparation of 1 Hpvrazoles.
基金supported by the National Natural Science Foundation of China (Grant No. 22001034)the Open Fund of the Jiangxi Province Key Laboratory of Synthetic Chemistry (Grant No. JXSC202008)the Research Found of East China University of Technology (Grant Nos. DHBK2019264, DHBK2019265, DHBK2019267)
文摘In this study,a sandwich-type uranium(Ⅵ)-containing silicotungstate KNa11H2(H2O)30[Na(UO2)(SiW9O34)]2·8H2O(1)with new three-dimensional(3D)structure was synthesized and characterized using single-crystal X-ray diffraction,Fourier transform infrared,Raman,solid-state ultraviolet–visible diffuse reflection spectra,thermogravimetric analysis and powder X-ray diffraction.Single crystal analysis revealed that the Na(I)-H2O clusters in 1 showed a two-dimensional structure similar to(4,4)-network and resulted in the formation of a new 3D structure of 1.In addition,it was notable that 1 presented excellent catalytic activity for the synthesis of substituted phenylsulfonyl-1H-pyrazoles via the cyclization reaction of 1,3-diketones with various substituted benzenesulfonyl hydrazides.
