Direct N-heterocyclization of hydrazines to access styrylated pyrazoles: synthesis of 1,3,5-trisubstituted pyrazoles and dihydropyrazoles
作者:Vunnam Venkateswarlu、Jaspreet Kour、K. A. Aravinda Kumar、Praveen Kumar Verma、G. Lakshma Reddy、Yaseen Hussain、Aliya Tabassum、Shilpi Balgotra、Sorav Gupta、Abhinandan D. Hudwekar、Ram A. Vishwakarma、Sanghapal D. Sawant
DOI:10.1039/c8ra04550j
日期:——
microwave-assisted method has been developed for the synthesis of tri-substituted pyrazoles via direct N-heterocyclization of hydrazines with metal-acetylacetonate and -dibenzylideneacetonate without using any base or additives. Most importantly, the synthesis of 1-aryl-5-phenyl-3-styryl-1H-pyrazoles was achieved in a single step using hydrochloride salt of various phenylhydrazines and this is the first
Cu<sub>1.5</sub>
PMo<sub>12</sub>
O<sub>40</sub>
-catalyzed condensation cyclization for the synthesis of substituted pyrazoles
作者:Guo-Ping Yang、Xing He、Bing Yu、Chang-Wen Hu
DOI:10.1002/aoc.4532
日期:2018.11
A convenient and direct approach has been developed for the preparation of pyrazole derivatives by the condensationcyclization of hydrazines/hydrazide and 1,3‐diketones in the presence of Cu1.5PMo12O40 (0.33 mol%) under mild conditions (r.t.‐60 °C, 10–30 min). Notably, the reaction was found to be scalable as 99% yield was obtained when the reaction was performed at a 5‐mmol scale. This solvent‐free
在温和的条件下(rt-60),在Cu 1.5 PMo 12 O 40(0.33 mol%)存在下,通过肼/酰肼和1,3-二酮的缩合环化反应,已经开发了一种方便直接的方法来制备吡唑衍生物。°C,10–30分钟)。值得注意的是,当反应在5 mmol规模下进行时,发现该反应可扩展,产率为99%。这种无溶剂和无卤素的催化体系代表了吡唑的一种有效的经济和环保方法。
Efficient Copper-Catalyzed Synthesis of Substituted Pyrazoles at Room Temperature
method for the synthesis of pyrazoles through a copper-catalyzed condensation reaction has been developed. The new catalytic system not only maintained a broad substrate scope but was also active under acid-free reaction conditions, overcoming the conventional requirement for an acid-catalyzed system. Furthermore, the copper catalyst enabled this reaction to be performed at roomtemperature and in a short
2D network structure of zinc(II) complex: A new easily accessible and efficient catalyst for the synthesis of pyrazoles
作者:Gang‐Ming Cao、Guo‐Dong Zeng、Ke Li、Yu‐Feng Liu、Xiao‐Ling Lin、Guo‐Ping Yang
DOI:10.1002/aoc.6379
日期:2021.11
Zn(II) coordinationpolymer [Zn3(paz)(btc)2(H2O)8]·4H2O}n (noted as ZnPB), where paz = pyrazine, H3btc = trimesic acid, was synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy and powder X-ray diffraction analyses. ZnPB shows a (3,3)-connected 2D network with a point symbol of (63)2. Hydrogenbonds and π···π interactions connect adjacent 2D network
Self-assembly of a new 3D platelike ternary-oxo-cluster: An efficient catalyst for the synthesis of pyrazoles
作者:Guoping Yang、Yufeng Liu、Xiaoling Lin、Bangming Ming、Ke Li、Changwen Hu
DOI:10.1016/j.cclet.2021.05.008
日期:2022.1
A new metal-oxo-clusters-based inorganic framework [NaCo2Mo2O7(OH)3]n (NaCoMo), named as 3D platelike ternary-oxo-cluster, has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction structure analysis, FT-IR spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS) analyses, X-ray photoelectron spectroscopy
一种新的基于金属-氧簇的无机骨架[NaCo 2 Mo 2 O 7(OH)3 ] n(NaCoMo)(NaCoMo)被称为3D板状三元氧簇,已通过水热合成并通过单晶X射线衍射结构分析,FT-IR光谱,粉末X射线衍射(PXRD),扫描电子显微镜(SEM)进行了表征),能量色散X射线能谱(EDS)分析,X射线光电子能谱(XPS)和热重分析(TGA)。结构分析表明,NaCoMo中没有经典的建筑单元,并且NaCoMo的不对称单元直接扩展为新的板状3D结构。密度泛函理论计算(DFT)表明,晶体形成过程是放热的,并且结构非常稳定。此外,该化合物在磺酰肼和1的缩合和环化反应中具有出色的催化活性。3-二酮合成吡唑,所需产物的收率高达99%。NaCoMo的成功合成代表了一种新型的非经典多金属氧酸盐的发现。