Dimethylzinc‐Initiated Radical Coupling of β‐Bromostyrenes with Ethers and Amines
作者:Amanda Sølvhøj、Andreas Ahlburg、Robert Madsen
DOI:10.1002/chem.201502429
日期:2015.11.2
A new coupling reaction has been developed in which β‐bromostyrenes react with ethers and tertiary amines to introduce the styryl group in the α‐position. The transformation is mediated by Me2Zn/O2 with 10 % MnCl2 and is believed to proceed by a radical addition–elimination mechanism. The ether and the amine are employed as solvent and the coupling takes place through the most stable α radical for unsymmetrical
已开发出一种新的偶联反应,其中β-溴苯乙烯与醚和叔胺反应,在α-位引入苯乙烯基。该转变是由具有10%MnCl 2的Me 2 Zn / O 2介导的,并且据认为是通过自由基加成-消除机理进行的。醚和胺用作溶剂,偶合通过非对称底物的最稳定的α基团发生。获得的产物为纯E异构体,产率中等至良好。可以使用一系列较小的环状和非环状醚/胺以及各种取代的β-溴苯乙烯实现偶联。
Irradiation-Induced Palladium-Catalyzed Decarboxylative Heck Reaction of Aliphatic <i>N</i>-(Acyloxy)phthalimides at Room Temperature
作者:Guang-Zu Wang、Rui Shang、Yao Fu
DOI:10.1021/acs.orglett.8b00023
日期:2018.2.2
It is reported that Pd(PPh3)2Cl2 in combination with 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) under irradiation of blue LEDs efficiently catalyzes a decarboxylative Heck reaction of vinyl arenes and vinyl heteroarenes with aliphatic N-(acyloxy)phthalimides at roomtemperature. A broad scope of secondary, tertiary, and quaternary carboxylates, including α-amino acid derived esters
NiCl2-catalyzed radical cross decarboxylative coupling between arylpropiolic acids and cyclic ethers
作者:Zi-juan Wan、Jin-yuan Wang、Jun Luo
DOI:10.1016/j.tetlet.2019.01.039
日期:2019.2
A direct alkenylation of cyclic ethers via radical cross decarboxylative coupling process catalyzed by NiCl2 and using DTBP as radicalinitiator and oxidant was developed. A variety of arylpropiolic acids and cyclic ethers were transformed into the corresponding 2-arylvinyl cyclic ethers in moderate to excellent yields. Mechanistic experiments were conducted to determine the nature of the reaction
Improved One-Pot Synthesis of Styryl Tetrahydrofurans and Cyclohexanes by Radical Addition to -Nitrostyrenes in the Presence of Benzoyl Peroxide
作者:Yeong-Jiunn Jang、Yuh-Kuo Shih、Jing-Yuan Liu、Wen-Yu Kuo、Ching-Fa Yao
DOI:10.1002/chem.200204571
日期:2003.5.9
Stereoselective styryl derivatives have been prepared based on radical substitution (addition-elimination) of heterocycles or cyclohydrocarbons units to (E)-beta-nitrostyrenes 1 using a common radical initiator benzoyl peroxide. High reactivity and selectivity with wide substrate scope were attained by using this easy methodology. The reactions using easily obtained and one-pot potential starting materials
Donor–Acceptor Complex Enables Alkoxyl Radical Generation for Metal‐Free C(sp
<sup>3</sup>
)–C(sp
<sup>3</sup>
) Cleavage and Allylation/Alkenylation
作者:Jing Zhang、Yang Li、Ruoyu Xu、Yiyun Chen
DOI:10.1002/anie.201707171
日期:2017.10.2
The alkoxyl radical is an essential and prevalent reactive intermediate for chemical and biological studies. Here we report the first donor–acceptor complex‐enabled alkoxyl radical generation under metal‐free reaction conditions induced by visible light. Hantzsch ester forms the key donor–acceptor complex with N‐alkoxyl derivatives, which is elucidated by a series of spectrometry and mechanistic experiments