Base initiated aromatization/C O bond formation: a new entry to O-pyrazole polyfluoroarylated ethers
摘要:
A base initiated intermolecular SNAr reaction of pyrazolones with polyfluoroarenes was developed. The process involved the isomerization aromatization of pyrazolone followed by the C-O bond formation via the selective C-F bond cleavage. With this strategy, a wide range of O-pyrazole polyfluoroarylated ethers bearing diverse functional groups were synthesized in mild to good yields. Additionally, our method was also applied to the isoxazol substrates. (C) 2014 Elsevier Ltd. All rights reserved.
Base initiated aromatization/C O bond formation: a new entry to O-pyrazole polyfluoroarylated ethers
摘要:
A base initiated intermolecular SNAr reaction of pyrazolones with polyfluoroarenes was developed. The process involved the isomerization aromatization of pyrazolone followed by the C-O bond formation via the selective C-F bond cleavage. With this strategy, a wide range of O-pyrazole polyfluoroarylated ethers bearing diverse functional groups were synthesized in mild to good yields. Additionally, our method was also applied to the isoxazol substrates. (C) 2014 Elsevier Ltd. All rights reserved.
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
This paper describes a facile, efficient, and clean synthesis of various pyrazolones by employing T3P® as a catalyst and performing the reaction under microwave irradiation. This two-step, one-pot reaction proceeded readily and tolerated a variety of functional groups. A wide range of pyrazolone derivatives were obtained in good to excellent yields.
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
Copper-catalyzed propargylic [3+3] cycloaddition with 1<i>H</i>-pyrazol-5(4<i>H</i>)-ones: enantioselective access to optically active dihydropyrano[2,3-<i>c</i>]pyrazoles
作者:Ling Li、Zhen-Ting Liu、Xiang-Ping Hu
DOI:10.1039/c8cc05706k
日期:——
A copper-catalyzed asymmetric propargylic [3+3] cycloaddition with 1H-pyrazol-5(4H)-ones as C,O-bisnucleophiles through the desilylation-activated strategy has been developed. With the catalysis of Cu(OAc)2·H2O in combination with a chiral tridentate P,N,N-ligand, the reaction displayed a broad substrate scope, and thus provided a variety of chiral dihydropyrano[2,3-c]pyrazoles in high yields and with
通过去甲硅烷基化活化策略,开发了以1 H-吡唑-5(4 H)-为C,O-双亲核试剂的铜催化不对称炔丙基[3 + 3]环加成反应。Cu(OAc)2 ·H 2 O与手性三齿P,N,N-配体结合催化,反应显示出较宽的底物范围,从而提供了多种手性二氢吡喃[2,3- c ]吡唑类化合物的收率高(对映体选择性高达96%ee)。
Organocatalytic diastereo- and enantioselective conjugate addition of pyrazol-3-ones to 3-trifluoroethylidene oxindoles with a newly developed squaramide catalyst
作者:Zhao Han、Jiaping Jin、Alemayehu Gashaw Woldegiorgis、Xufeng Lin
DOI:10.1039/d2ra05088a
日期:——
An efficient organocatalyticconjugatedaddition reaction of pyrazol-3-ones with 3-trifluoroethylidene oxindoles has been developed for the synthesis of enantioenriched triflouromethylated indolin-2-ones bearing adjacent tertiary chiral centers in good yields and good to excellent diastereo- and enantioselectivities. The use of a newly developed chiral spirobiindane-derived squaramide catalyst is essential