Benzaldazin Lagert Zwei MolekelnAcrylsäure-甲酯 Das Additions生产的产品被吡唑烷二酮-(1,2)-吡唑醇丁(XVII)取代,是羟丁二酸Abbau zu 3-Phenylpyrazol的衍生物,并且是Vergleich des IR.-Spektrums mit den IR.-Spektrencher zweier的衍生物。 ,2)-吡唑烷酮 替代品生产合同书 呋喃丹嗪二甲酸酯与模拟产品类似物生产的甲基丙烯酸酯。
Divergent synthesis of 1,3,5-tri and 1,3-disubstituted pyrazoles under transition metal-free conditions
作者:Liyao Ma、Pengcheng Ou、Xueliang Huang
DOI:10.1039/d0ob01478h
日期:——
Pyrazole cores are common structural motifs existing in various agrochemicals and pharmaceuticals. Herein, a transition metal-free, three-component reaction of arylaldehydes, ethyl acrylate and N-tosylhydrazones is described, which leads to the formation of 1,3,5-trisubstituted and 1,3-disubstituted pyrazoles divergently under slightly different conditions.
Efficient one-pot synthesis of substituted pyrazoles
作者:Meng Tang、Fu-Min Zhang
DOI:10.1016/j.tet.2012.12.038
日期:2013.2
An efficient, one-potsynthesis of substituted pyrazoles from enones, hydrazides, and halides was developed. In comparison with the classical Knorr pyrazolesynthesis, this methodology gave a different type of product (R3≥R5). A range of substituted pyrazoles were prepared in good to high yields with complete regioselectivity.
Copper-Catalyzed Aerobic Intramolecular Dehydrogenative Cyclization of N,N-Disubstituted Hydrazones through C sp 3H Functionalization
作者:Guangwu Zhang、Yan Zhao、Haibo Ge
DOI:10.1002/anie.201209618
日期:2013.2.25
An aerobic activity: The title reaction proceeds through an oxidation/cyclization/aromatization sequence under an atmosphere of O2 (see scheme; DBU=1,8‐diazabicyclo[5.4.0]undec‐7‐ene, DCE=1,2‐dichloroethane, DMS=dimethylsulfide). This coupling reaction is the first to proceed via an iminium intermediate for a CH bond‐functionalization process, and provides an environmentally friendly and atom‐efficient
Cu‐Promoted Sydnone Cycloadditions of Alkynes: Scope and Mechanism Studies
作者:Júlia Comas‐Barceló、Robert S. Foster、Béla Fiser、Enrique Gomez‐Bengoa、Joseph P. A. Harrity
DOI:10.1002/chem.201406118
日期:2015.2.16
reaction of sydnones and terminal alkynes, providing significant reduction in reaction times. Specifically, the use of Cu(OTf)2 is found to provide 1,3‐disubstituted pyrazoles, whereas simply switching the promoter system to Cu(OAc)2 allows the corresponding 1,4‐isomers to be produced. The mechanism of the Cu‐effect in each case has been investigated by experimental and theoretical studies, and they