A General and Convenient Palladium-Catalyzed Carbonylative Sonogashira Coupling of Aryl Bromides
作者:Xiao-Feng Wu、Helfried Neumann、Matthias Beller
DOI:10.1002/chem.201001864
日期:2010.10.25
Convenient carbonylations: An efficient methodology for the carbonylative Sonogashira reaction of aryl bromides has been developed (see scheme). Contrary to known procedures, inexpensive aryl bromides can be applied as substrates to give the desired compounds in moderate to good yields (47–88 %).
Base-mediated benzannulation of α-cyanocrotonates with ynones: facile synthesis of benzonitriles and fluorenes
作者:Maneesh Kumar Reddy Singam、Attunuri Nagireddy、Sridhar Reddy Maddi
DOI:10.1039/d0gc00608d
日期:——
Benzonitriles and cyanofluorenes have been rapidly obtained via the [3 + 3] benzannulation of readily available alkynones and α-cyanocrotonates using KOtBu as the only reagent and EtOH (and CO2) is the only by-product.
This benzannulation was also explored with furan/thiophene based o-halo ynones wherein a Michael addition-SNAr process operates and nitromethanes leave their imprint to deliver nitro substituted benzo-furans and -thiophenes.
已发现区域异构的 2-或 3-取代呋喃和噻吩炔酮与一系列硝基甲烷的方便的一锅苯并环化可直接获得密集且多样化的功能化苯并呋喃和苯并噻吩。在该协议中,硝基甲烷中的硝基作为递归碳负离子活化剂来设置串联迈克尔加成-6π-电环化,其最终的牺牲消除促进了芳构化和整体苯环化。还使用基于呋喃/噻吩的邻卤炔酮对这种苯环化进行了探索,其中迈克尔加成-S N Ar 过程运行,硝基甲烷留下它们的印记以提供硝基取代的苯并呋喃和噻吩。
Organocatalytic Asymmetric Michael/Dieckmann Cyclization Reaction of Alkynones To Construct Spirocyclopentene Oxindoles
作者:Jiawen Lang、Yi Li、Tengfei Kang、Xiaoming Feng、Xiaohua Liu
DOI:10.1021/acs.orglett.9b02519
日期:2019.9.6
catalysis of a chiral guanidine catalyst and NaH. This protocol provides access to a wide range of synthetically useful optically active spirocyclopentenone oxindoles and their derivatives under mild reaction conditions.
Palladium-Catalyzed Carbonylative Sonogashira Coupling of Aryl Bromides via <i>tert</i>-Butyl Isocyanide Insertion
作者:Ting Tang、Xiang-Dong Fei、Zhi-Yuan Ge、Zhong Chen、Yong-Ming Zhu、Shun-Jun Ji
DOI:10.1021/jo4001096
日期:2013.4.5
A simple and efficient palladium-catalyzed carbonylative Sonogashiracoupling via tert-butyl isocyanide insertion has been developed, which demonstrates the utility of isocyanides in intermolecular C–C bond construction. This methodology provides a novel pathway for the synthesis of alkynyl imines which can undergo simple silica gel catalyzed hydrolysis to afford alkynones. The approach is tolerant