作者:Qi-Liang Yang、Yi-Kang Xing、Xiang-Yang Wang、Hong-Xing Ma、Xin-Jun Weng、Xiang Yang、Hai-Ming Guo、Tian-Sheng Mei
DOI:10.1021/jacs.9b11915
日期:2019.12.4
Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C-H functionalization, yet this type of transformation has thus far mainly been limited to arene C-H functionaliza-tion. Herein, we report the development of electrochemi-cal vinylic C-H functionalization of acrylic acids with al-kynes. In this reaction an iridium catalyst enables C-H/O-H
Synthesis of Isocoumarins and α-Pyrones via Palladium-Catalyzed Annulation of Internal Alkynes
作者:Richard C. Larock、Mark J. Doty、Xiaojun Han
DOI:10.1021/jo9821628
日期:1999.11.1
factors. A number of 3,4-disubstituted isocoumarins and polysubstituted alpha-pyrones have been prepared in good yields by treating halogen- or triflate-containing aromatic and alpha,beta-unsaturated esters, respectively, with internalalkynes in the presence of a palladium catalyst. Synthetically, the methodology provides an especially simple and convenient regioselective route to isocoumarins and alpha-pyrones
Oxidative Annulation of Arenecarboxylic and Acrylic Acids with Alkynes under Ambient Conditions Catalyzed by an Electron-Deficient Rhodium(III) Complex
It has been established that an electron‐deficient CpE rhodium(III) complex catalyzes the oxidative [4+2] annulation of substituted arenecarboxylic and acrylic acids with alkynes under ambient conditions (at RT–40 °C, under air) without using excess amounts of substrates to produce the corresponding substituted isocoumarins and α‐pyrones in high yields. Minor modification of reaction conditions depending
A highly efficient rhodium(III)‐catalyzed directoxidative annulation of acrylicacid with alkynes to form α‐pyrones was developed. Various substituted acrylicacids were compatible in this transformation, affording the corresponding products in moderate to excellent yields under mild conditions.
Synthesis of Functionalized α-Pyrone and Butenolide Derivatives by Rhodium-Catalyzed Oxidative Coupling of Substituted Acrylic Acids with Alkynes and Alkenes
The straightforward and efficient synthesis of α-pyrone and butenolide derivatives has been achieved by the rhodium-catalyzedoxidativecoupling reactions of substituted acrylic acids with alkynes and alkenes, respectively. Some α-pyrones obtained exhibit solid-state fluorescence.