Unusual Reactivity of 4-Vinyl Isoxazoles in the Copper-Mediated Synthesis of Pyridines, Employing DMSO as a One-Carbon Surrogate
作者:Pravin Kumar、Manmohan Kapur
DOI:10.1021/acs.orglett.0c01935
日期:2020.8.7
An efficient protocol for the synthesis of nicotinate derivatives and tetrasubstituted pyridines through a copper-mediated cleavage of isoxazoles has been developed. The highlight of the work is the observation of an unusualreactivity of 4-vinyl isoxazoles under the reaction conditions. DMSO serves as a one-carbon surrogate generating an active methylene group during the reaction to form two C–C bonds
Facile one-pot preparation of 5-aryltetrazoles and 3-arylisoxazoles from aryl bromides
作者:Eiji Kobayashi、Hideo Togo
DOI:10.1016/j.tet.2018.06.044
日期:2018.8
The successive treatment of aryl bromides with n-BuLi, DMF, hydroxylaminehydrochloride, and finally diphenylphosphoryl azide provided efficiently the corresponding 5-aryltetrazoles in good to moderate yields. Similarly, the successive treatment of aryl bromides with n-BuLi, DMF, hydroxylaminehydrochloride, and finally diethyl acetylenedicarboxylate and Oxone® provided efficiently the corresponding
Rhodium-Catalyzed Cascade Annulative Coupling of 3,5-Diarylisoxazoles with Alkynes
作者:Teppei Noguchi、Yuji Nishii、Masahiro Miura
DOI:10.1055/s-0037-1610376
日期:2019.1
the sequential construction of isoquinoline and naphtho[1,8-bc]pyran frameworks connected by a biaryl linkage is achieved by a single operation. Most of the obtained polycyclic compounds exhibit visible fluorescence in both the solution and the solid state. The hexaphenylated isoquinoline-naphthopyran conjugate (R = Ph) as a representative product shows a green emission which can be turned off by making
作为《五十周年综合报告》的一部分发行-黄金周年纪念日 抽象的 在Cu(II)氧化剂存在下,铑催化的3,5-二芳基异恶唑与三当量炔烃的级联环氧化反应平稳进行,其中异喹啉和萘并[1,8- bc ]吡喃骨架的顺序结构相连联芳键的单键操作是通过一次操作即可实现的。大部分获得的多环化合物在溶液和固态下均显示可见的荧光。作为代表产物的六苯基化异喹啉-萘并吡喃共轭物(R = Ph)显示绿色发射,可通过用酸制备异喹啉鎓盐来关闭该发射。通过用碱处理也可逆地开启发射。 在Cu(II)氧化剂存在下,铑催化的3,5-二芳基异恶唑与三当量炔烃的级联环氧化反应平稳进行,其中异喹啉和萘并[1,8- bc ]吡喃骨架的顺序结构相连联芳键的单键操作是通过一次操作即可实现的。大部分获得的多环化合物在溶液和固态下均显示可见的荧光。作为代表产物的六苯基化异喹啉-萘并吡喃共轭物(R = Ph)显示绿色发射,可通过用酸制备异喹啉鎓盐
Synthesis of isoxazoles by hypervalent iodine-induced cycloaddition of nitrile oxides to alkynes
作者:Anup M. Jawalekar、Erik Reubsaet、Floris P. J. T. Rutjes、Floris L. van Delft
DOI:10.1039/c0cc04646a
日期:——
Treatment of oximes with hypervalent iodine leads to substituted isoxazoles via rapid formation of nitrile oxides. Reaction with terminal alkynes led to a series of 3,5-disubstituted isoxazoles with complete regioselectivity and high yield, in a procedure mild enough to prepare a range of nucleoside and peptide conjugates. Exceptionally high reactionrates were found for the formation of 3,4,5-trisubstituted