A Palladium NNC-Pincer Complex as an Efficient Catalyst Precursor for the Mizoroki−Heck Reaction
作者:Go Hamasaka、Shun Ichii、Yasuhiro Uozumi
DOI:10.1002/adsc.201800099
日期:2018.5.2
The Mizoroki−Heckreaction of aryl halides (iodides, bromides, or chlorides) with activated alkenes in the presence of a palladium NNC‐pincer complex at ppb to ppm loadings gave the corresponding internal alkenes in excellent yields. The total turnover number and turnover frequency reached up to 8.70×108 and 1.21×107 h−1 (3.36×103 s−1), respectively. The catalyst was applied in a ten‐gram‐scale synthesis
芳族卤化物(碘化物,溴化物或氯化物)与活性烯烃在钯NNC-钳夹配合物(ppb)至ppm负载量下的Mizoroki-Heck反应得到了相应的内部烯烃,收率很好。总周转次数和周转频率分别达到8.70×10 8和1.21×10 7 h -1(3.36×10 3 s -1)。该催化剂用于UV-B防晒剂辛诺酸酯(2-乙基己基4-甲氧基肉桂酸酯)的10克级合成。反应速率分析,反应混合物的透射电子显微镜检查和中毒试验表明,单体钯物质是催化循环中的催化活性物质。
In Situ Generation of Palladium Nanoparticles: Reusable, Ligand-Free Heck Reaction in PEG-400 Assisted by Focused Microwave Irradiation
作者:Zhengyin Du、Lin Bai、Wanwei Zhou、Fen Wang、Jin-Xian Wang
DOI:10.1055/s-0030-1259310
日期:2011.2
A rapid and efficient Heck coupling reaction of aryl iodides with terminal olefins was conducted in PEG-400 at 120 ËC in the presence of potassium carbonate and palladium nanoparticles formed in situ from palladium chloride under focused microwave irradiation. High to excellent product yields were achieved. The reaction medium and catalyst could be easily recycled at least five times without significant loss in reactivity.
Hydrothermal Heck reaction catalyzed by Ni nanoparticles
作者:Wu Zhang、Hongling Qi、Liusan Li、Xiang Wang、Jie Chen、Kaishan Peng、Zhenghua Wang
DOI:10.1039/b900697d
日期:——
A novel environmentally benign Heck reaction using Ni nanoparticles as catalysts under hydrothermal conditions has been developed in the absence of phosphine ligands without the protection of an inert atmosphere. The results showed that the aryl iodides and bromides could carry out the coupling reaction with a variety of alkenes by hydrothermal treatment. More importantly, the cheap catalysts are stable under the reaction conditions and retain good to moderate activity for at least six successive runs without any additional activation treatment. This approach would be very useful from a practical viewpoint.
Novel isoxazoline ligand with ferrocene backbone: preparation and application in Heck reaction with water as solvent
作者:Shuyan Yu、Zhiqin Zhang、Zhiyu Yu、Yongjia Shang
DOI:10.1002/aoc.3176
日期:2014.8
Two novelisoxazoline N,N‐bidentate ligands with ferrocenebackbone have been synthesized and employed for the palladium‐catalyzed Heck coupling reaction. Among them, 1,3‐bis‐(5‐ferrocenylisoxazoline‐3‐yl)benzene was found to be thermally stable and a highly effective ligand for Heck coupling reaction in neat water without N2 protection, affording the desired coupling products in good to excellent
Homeopathic Ligand-Free Palladium as a Catalyst in the Heck Reaction. A Comparison with a Palladacycle
作者:André H. M. de Vries、Jan M. C. A. Mulders、John H. M. Mommers、Huub J. W. Henderickx、Johannes G. de Vries
DOI:10.1021/ol035184b
日期:2003.9.1
[reaction: see text] Ligand-free Pd(OAc)(2) can be used as a catalyst in the Heck reaction of aryl bromides as long as the amount of catalyst is kept between 0.01 and 0.1 mol %. At higher concentrations palladium black forms and the reaction stops. The actual catalyst is monomeric. Palladacycles merely serve as a source of ligand-freepalladium in Heck reactions of aryl bromides.