The visible-light-induced acylation/cyclization of alkynoates with acyl oximes for the construction of 3-acylcoumarins
作者:Quan Zhou、Fang-Ting Xiong、Pu Chen、Bi-Quan Xiong、Ke-Wen Tang、Yu Liu
DOI:10.1039/d1ob01568k
日期:——
by the visible-light-induced acylation/cyclization of alkynoates with various acyl oximecompounds in acetonitrile. The difunctionalization of carbon–carbon triple bonds precedes the generation of iminyl radicals, which is followed by the formation of acyl radicals. The acyl radicals then attack the carbon–carbon triple bonds, followed by 5-exo-trig cyclization and 1,2-ester migration. This strategy
Visible-light photoredox catalyzed cyclization of aryl alkynoates for the synthesis of trifluoromethylated coumarins
作者:Mei-jie Bu、Guo-ping Lu、Chun Cai
DOI:10.1016/j.catcom.2018.06.009
日期:2018.8
for the synthesis of coumarin derivatives via visible-lightphotoredoxcatalysis has been developed using fac-Ir(ppy)3 as the photocatalyst under mild conditions. Trifluoromethanesulfonyl chloride is utilized as the trifluoromethylation reagent, which is cheap and readily available. Aryl alkynoates are trifluoromethylated, then undergo a radical cyclization and a cascade ester migration to generate target
α-Amino Acid Sulfonamides as Versatile Sulfonylation Reagents: Silver-Catalyzed Synthesis of Coumarins and Oxindoles by Radical Cyclization
作者:Kyalo Stephen Kanyiva、Daisuke Hamada、Sohei Makino、Hideaki Takano、Takanori Shibata
DOI:10.1002/ejoc.201800901
日期:2018.11.25
silver‐catalyzed sulfonylation strategy using sulfonamides derived from α‐amino acids is described. The reaction proceeded via decarboxylation, N–S bond cleavage and radical cyclization to provide a variety of coumarins. The reaction was suitable for the synthesis of 2‐oxindoles and an isoquinolinedione by the capturing of the sulfonyl radical with an alkene moiety and cyclization.
Silver-Mediated Radical Cyclization of Alkynoates and α-Keto Acids Leading to Coumarins via Cascade Double C–C Bond Formation
作者:Kelu Yan、Daoshan Yang、Wei Wei、Fen Wang、Yuanyuan Shuai、Qiannan Li、Hua Wang
DOI:10.1021/jo502474z
日期:2015.2.6
A novel and convenient silver-mediated radicalcyclization method for the synthesis of coumarin derivatives via the direct difunctionalization of alkynoates with α-keto acids through double C–C bondformation under mild conditions has been developed. This new method is highly efficient and practical, and the starting materials are readily prepared. The present method should provide a useful strategy
Direct and metal-free arylsulfonylation of alkynes with sulfonylhydrazides for the construction of 3-sulfonated coumarins
作者:Wei Wei、Jiangwei Wen、Daoshan Yang、Mengyuan Guo、Yingying Wang、Jinmao You、Hua Wang
DOI:10.1039/c4cc08117j
日期:——
A novel and metal-free procedure has been developed for the construction of sulfonated coumarins via direct arylsulfonylation of alkynes with sulfonylhydrazides.