Enantioselective Copper-Catalyzed [3 + 3] Cycloaddition of Tertiary Propargylic Esters with 1<i>H</i>-Pyrazol-5(4<i>H</i>)-ones toward Optically Active Spirooxindoles
作者:You-Wei Xu、Ling Li、Xiang-Ping Hu
DOI:10.1021/acs.orglett.0c03587
日期:2020.12.18
A copper-catalyzed enantioselective [3 + 3] cycloaddition of 3-ethynyl-2-oxoindolin-3-yl acetates with 1H-pyrazol-5(4H)-ones for the construction of optically active spirooxindoles bearing a spiro all-carbon quaternarystereocenter has been realized. With a combination of Cu(OTf)2 and chiral tridentate ketimine P,N,N-ligand as the catalyst, the reaction displayed broad substrate scopes, good yields
Structure-activity relationships of pyrazole-4-carbodithioates as antibacterials against methicillin–resistant Staphylococcus aureus
作者:Hiwa Majed、Tatiana Johnston、Celine Kelso、Enrico Monachino、Slobodan Jergic、Nicholas E. Dixon、Eleftherios Mylonakis、Michael J. Kelso
DOI:10.1016/j.bmcl.2018.09.038
日期:2018.12
synthesized, their anti-MRSA structure-activityrelationships evaluated and selectivity versus human HKC-8 cells determined. Minimum inhibitory concentrations (MIC) ranged from 0.5 to 64 μg/mL and up to 16-fold selectivity was achieved. The 4-carbodithioate function was found to be essential for activity but non-specific reactivity was ruled out as a contributor to antibacterial action. The study supports
Tandem stereoselective synthesis of new trifluoromethylated pyranopyrazoles
作者:Jian Wang、Guan-Bo Huang、Li-Jun Yang、Feng Li、Jing Nie、Jun-An Ma
DOI:10.1016/j.jfluchem.2014.10.008
日期:2015.3
trifluoromethyl ketones is described. The notable features of this tandem process are its operational simplicity, easily accessible starting materials, and mild reaction conditions. The corresponding trifluoromethylated pyranopyrazoles were obtained in excellent yields (85–99%) with good to excellent diastereoselectivities (6:1–30:1). In addition, the stereochemical assignment of the major isomer by X-ray crystallographic
Highly Diastereo- and Enantioselective Organocatalytic One-Pot Sequential 1,4-Addition/Dearomative-Fluorination Transformation
作者:Feng Li、Long Sun、Yuou Teng、Peng Yu、John Cong-Gui Zhao、Jun-An Ma
DOI:10.1002/chem.201202636
日期:2012.11.5
Fluorination: A wide range of nitroolefins and pyrazol‐5‐ones undergo a sequential 1,4‐addition/dearomative‐fluorination transformation when treated with a catalytic amount of a tertiary‐amine—thiourea compound and the terminal electrophile, N‐fluorobenzenesulfonimide, to give fluorinated products in 72–95 % yield with up to 99:1 d.r. and 98 % ee. Notably, these products contain adjacent tertiary and
One-Pot Asymmetric Synthesis of Spiropyrazolone-Linked Cyclopropanes and Benzofurans through a General Michael Addition/Chlorination/Nucleophilic Substitution Sequence
A sequential and general strategy has been successfully developed for the synthesis of spiropyrazolone scaffolds. This intriguing transformation of the asymmetric multicomponent catalysis process was realized with the combination of Michael addition/chlorination/nucleophilic substitution in a one-pot sequence, giving rise to a series of spiropyrazolones with fully substituted cyclopropanes and spi