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.
A copper-mediatedintramolecular aza-Wacker-type cyclization was developed for the direct and efficient synthesis of 3-aryl indoles using 2-alkenylanilines in moderate to good yields with good functional group compatibility. This strategy shows the high efficiency, operational simplicity as well as broad substrate scope.
Carbon annulation of ortho-vinylanilines with dimethyl sulfoxide to access 4-aryl quinolines
作者:Jin Yuan、Jin-Tao Yu、Yan Jiang、Jiang Cheng
DOI:10.1039/c6ob02714h
日期:——
A palladium-catalyzed annulation of ortho-vinylanilines with dimethylsulfoxide was developed to access 4-aryl quinolines in moderate to good yields. Activated by 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) adduct (DABSO), DMSO served as a “CH–” fragment in this transformation. It represents a facile pathway leading to 4-aryl quinolines.
A convenient synthetic method for 2-polyfluoroalkylated quinoline systems through the efficient generation of perfluoroalkylated imine from o-vinylanilines with perfluorinated hemiacetals or aldehyde hydrates was developed. In most cases, the major products are 2-polyfluoroalkyl-1,2-dihydroquinoline derivatives 3, which can be converted to either quinolines or 1,2,3,4-tetrahydroquinolines.