Synthesis of Isoxazolines from Nitroalkanes
<i>via</i>
a [4+1]‐Annulation Strategy
作者:Pavel Yu. Ushakov、Elizaveta A. Khatuntseva、Yulia V. Nelyubina、Andrey A. Tabolin、Sema L. Ioffe、Alexey Yu. Sukhorukov
DOI:10.1002/adsc.201901000
日期:2019.12.3
using the [4+1]‐annulation of α‐keto‐stabilized sulfur ylides with N,N‐bis(siloxy)enamines derived from aliphatic nitro compounds. The resulting 5‐keto‐substituted isoxazolines were shown to be convenient precursors of polysubstituted 3‐hydroxypyrrolidines via the one‐pot catalytic N−O hydrogenolysis/intramolecular reductive amination sequence. Application of this approach to the formal synthesis of Merck's
Construction of a Benzo[<i>b</i>]azepine Skeleton through Decarboxylative Ylide [6+1] Annulations with Modified Vinyl Benzoxazinanones
作者:Qing-Zhu Li、Zhi-Qiang Jia、Lin Chen、Xiang Zhang、Hai-Jun Leng、Rong Zeng、Yan-Qing Liu、Wen-Lin Zou、Jun-Long Li
DOI:10.1021/acs.orglett.0c04041
日期:2021.2.5
A Lewis acid-promoted [6+1] annulation between sulfur ylides and modified vinyl benzoxazinanones was described. In this reaction, the newly designed vinyl benzoxazinanones could serve as a novel six-atom synthon, and the key to success is the installation of an electron-withdrawing group on the alkene moiety of the benzoxazinanones. A broad range of substrates are compatible with this mild reaction
描述了路易斯酸促进硫基化物和改性乙烯基苯并恶嗪酮之间的[6 + 1]环化。在该反应中,新设计的乙烯基苯并恶嗪酮可以用作新型的六原子合成子,成功的关键是在苯并恶嗪酮的烯烃部分上安装了一个吸电子基团。各种各样的底物都与这种温和的反应体系兼容,从而为构建苯并[ b ]氮杂骨架提供了简便实用的方法。
Amine-catalyzed formal (3 + 3) annulations of 2-(acetoxymethyl)buta-2,3-dienoate with sulfur ylides: synthesis of 4H-pyrans bearing a vinyl sulfide group
作者:Kun Li、Jian Hu、Hui Liu、Xiaofeng Tong
DOI:10.1039/c2cc30242j
日期:——
A DABCO-catalyzed (3 + 3) annulation between 2-(acetoxymethyl)buta-2,3-dienoate and sulfur ylides has been developed, which provides a facile method for the synthesis of 4H-pyrans bearing a vinyl sulfide group.
Syntheses of 2-Aroyl Benzofurans through Cascade Annulation on Arynes
作者:Pashikanti Gouthami、Lahu N. Chavan、Rambabu Chegondi、Srivari Chandrasekhar
DOI:10.1021/acs.joc.8b00360
日期:2018.3.16
The highlyefficient and expedient route for the syntheses of 2-aroyl benzofurans has been developed via the cascade [2+2] followed by a [4+1] annulation on arynes. The overall transformation proceeded through the formation of ortho-quinone methide by the insertion of transient aryne into N,N-dimethylformamide and subsequent trapping with sulfurylide. Moreover, this transformation has a broad range
A simple, general route to the 2,3-dihydrobenzofurans substituted at C3 by an aryethynyl or aryl group, starting from propargylamine and itsderivatives with benzoyl sulfonium salts, has been developed. This reaction involved an in situ generated o-quinone methide (o-QM) intermediate followed by [4+1] annulation with sulfur ylides. Notably, this protocol's features include moderate to excellent yields