polysubstituted quinolinesfrom o-vinyl anilines and aldehydes. The reaction proceeds in a cascade manner through condensation, electrocyclization and dehydrogenation, and gives access to a wide range of quinolines with alkyl and/or aryl substituents as demonstrated with 40 examples. The metal-free catalytic procedure allows a heterogeneous protocol for the synthesis of various polysubstituted quinolines. The
Cleavage of C–C Bonds for the Synthesis of C2-Substituted Quinolines and Indoles by Catalyst-Controlled Tandem Annulation of 2-Vinylanilines and Alkynoates
作者:Jixiang Ni、Yong Jiang、Zhenyu An、Rulong Yan
DOI:10.1021/acs.orglett.8b00260
日期:2018.3.16
and alkynoates through C–C bond cleavage is developed. With these general methods, 2-substituted indoles and quinolines can be accessed via tandem Michael addition and cyclization with no requirement of oxidant. This strategy not only provides a method for the synthesis C2-substituted indoles in good yields through the simultaneous cleavage of C═C and C≡C bonds under metal-free conditions but also provides
tert-Butyl nitrite (TBN) as the N atom source for the synthesis of substituted cinnolines with 2-vinylanilines and a relevant mechanism was studied
作者:XiaoBo Pang、LianBiao Zhao、DaGang Zhou、Ping Yong He、ZhenYu An、Ji Xiang Ni、RuLong Yan
DOI:10.1039/c7ob01553d
日期:——
A green method to synthesize cinnolines by 6π electrocyclic reaction with alkenyl amines and TBN has been developed. TBN plays a dual role both as the nitrogen atom source and oxidant in this procedure. Relevant mechanism experiments reveal the reaction proceeds through electrocyclic reaction and with diazo hydroxide as a key intermediate.
Palladium-catalyzed cascade reactions of alkene-tethered carbamoyl chlorides with <i>N</i>-tosyl hydrazones: synthesis of alkene-functionalized oxindoles
A palladium-catalyzed cascade reaction of alkene-tethered carbamoylchlorides with N-tosyl hydrazones is described. It provided a new way to synthesize various alkene-functionalized oxindoles bearing an all-carbon quaternary center. The olefin moieties could serve as versatile handles for further elaboration. This transformation was highly efficient and showed good functional group tolerance.
Metal-Free Synthesis of 2-Fluoroalkylated Quinolines Using Polyfluoroalkanoic Acids as Direct Fluorine Sources
作者:Jiang Nan、Yan Hu、Pu Chen、Yangmin Ma
DOI:10.1021/acs.orglett.9b00039
日期:2019.4.5
A novel [5 + 1] cyclization of 2-vinylanilines with polyfluoroalkanoic acids under catalyst- and additive-free conditions was successfully implemented. The approach directly employs very low-cost and readily available polyfluoroalkanoic acids as both C1 synthons and fluoroalkyl building blocks. This method provides concise access to diverse 2-fluoroalkylated (CF3, C2F5, C3F7, CF2H, CF2Cl, and CF2Br)
在无催化剂和无添加剂的条件下,成功地实现了多氟链烷酸对2-乙烯基苯胺的新型[5 +1]环化反应。该方法直接采用成本非常低廉且易于获得的多氟链烷酸作为C1合成子和氟代烷基构件。该方法可以简便地获得高收率的多种2-氟烷基化(CF 3,C 2 F 5,C 3 F 7,CF 2 H,CF 2 Cl和CF 2 Br)喹啉,并具有优异的官能团耐受性,且收率高。克秤。