共查询到20条相似文献,搜索用时 15 毫秒
1.
Guozhu Zhang Yu Peng Dr. Li Cui Dr. Liming Zhang Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(17):3112-3115
Oxidizing gold? A gold(I)/gold(III) catalytic cycle is essential for the first oxidative cross‐coupling reaction in gold catalysis. By using Selectfluor for gold(I) oxidation, this chemistry reveals the synthetic potential of incorporating gold(I)/gold(III) catalytic cycles into contemporary gold chemistry and promises a new area of gold research by merging powerful gold catalysis and oxidative metal‐catalyzed cross‐coupling reactions.
2.
Gold(I)‐Catalyzed Diazo Cross‐Coupling: A Selective and Ligand‐Controlled Denitrogenation/Cyclization Cascade 下载免费PDF全文
Guangyang Xu Chenghao Zhu Dr. Weijin Gu Dr. Jian Li Prof. Dr. Jiangtao Sun 《Angewandte Chemie (International ed. in English)》2015,54(3):883-887
An unprecedented gold‐catalyzed ligand‐controlled cross‐coupling of diazo compounds by sequential selective denitrogenation and cyclization affords N‐substituted pyrazoles in a position‐switchable mode. This novel transformation features selective decomposition of one diazo moiety and simultaneous preservation of the other one from two substrates. Notably, the choice of the ancillary ligand to the gold complex plays a pivotal role on the chemo‐ and regioselectivity of the reactions. 相似文献
3.
Direct Arylation of N‐Heteroarenes with Aryldiazonium Salts by Photoredox Catalysis in Water 下载免费PDF全文
Prof. Dr. Dong Xue Zhi‐Hui Jia Cong‐Jun Zhao Yan‐Yan Zhang Prof. Dr. Chao Wang Prof. Dr. Jianliang Xiao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(10):2960-2965
A highly effective visible light‐promoted “radical‐type” coupling of N‐heteroarenes with aryldiazonium salts in water has been developed. The reaction proceeds at room temperature with [Ru(bpy)3]Cl2 ? 6 H2O as a photosensitizer and a commercial household light bulb as a light source. Pyridine and a variety of substituted pyridines are effective substrates under these reaction conditions, and only monosubstituted products are formed with different regioselectivities. Using aqueous formic acid as solvent, an array of xanthenes, thiazole, pyrazine, and pyridazine are compatible with this new arylation approach. The broad substrate scope, mild reaction conditions, and use of water as reaction solvent make this procedure a practical and environmentally friendly method for the synthesis of compounds containing aryl‐heteroaryl motifs. 相似文献
4.
5.
Gold‐Catalyzed Allylation of Aryl Boronic Acids: Accessing Cross‐Coupling Reactivity with Gold 下载免费PDF全文
Mark D. Levin Prof. Dr. F. Dean Toste 《Angewandte Chemie (International ed. in English)》2014,53(24):6211-6215
A sp3–sp2 C? C cross‐coupling reaction catalyzed by gold in the absence of a sacrificial oxidant is described. Vital to the success of this method is the implementation of a bimetallic catalyst bearing a bis(phosphino)amine ligand. A mechanistic hypothesis is presented, and observable transmetalation, C? Br oxidative addition, and C? C reductive elimination in a model gold complex are shown. We expect that this method will serve as a platform for the development of novel transformations involving redox‐active gold catalysts. 相似文献
6.
7.
8.
9.
10.
11.
Ligand‐Promoted Oxidative Cross‐Coupling of Aryl Boronic Acids and Aryl Silanes by Palladium Catalysis 下载免费PDF全文
Jingxun Yu Jun Liu Guangfa Shi Changdong Shao Prof. Dr. Yanghui Zhang 《Angewandte Chemie (International ed. in English)》2015,54(13):4079-4082
The first cross‐coupling reaction between aryl silanes and aryl boronic acids is described. This transformation represents one of the very few examples of coupling reactions between two nucleophilic organometallic reagents and provides a new method for the formation of biaryl compounds. The successful development of this reaction was enabled by the use of commercially available 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) as the ligand. A small amount of BINAP (3 mol %) was sufficient to suppress the formation of the homocoupling products, and the reaction yielded the cross‐coupling products with high selectivity under mild conditions, even when the ratio of the two coupling partners was 1:1. 相似文献
12.
Dr. Jin Wang Chiyu Wei Xuming Li Pengyi Zhao Chuan Shan Lukasz Wojtas Prof. Dr. Hao Chen Prof. Dr. Xiaodong Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(27):5946-5950
Gold-catalyzed alkyne and allene diselenations were developed. Excellent regioselectivity (trans) and good to excellent yields were achieved (up to 98 % with 2 % catalyst loading) with a wide range of substrates. Mechanistic investigation revealed the formation of a vinyl gold(I) intermediate followed by an intermolecular selenium cation migration, suggesting that a gold(I/III) redox process was successfully implemented under mild conditions. 相似文献
13.
14.
Hai‐Jun Tang Xinggui Zhang Yu‐Feng Zhang Chao Feng 《Angewandte Chemie (International ed. in English)》2020,59(13):5242-5247
A strategically novel synthetic method for the fluoroarylation of allenic ester was developed that enables the expedient construction of a host of β‐fluoroalkyl‐containing cinnamate derivatives. The reaction proceeds through visible‐light‐promoted gold redox catalysis, occurs smoothly under very mild reaction conditions, accommodates a large variety of functional groups, and more importantly allows the incorporation of fluorine and aryl groups with excellent regio‐ and stereoselectivity. The concomitant activation mode for both the allene motif and the hydrogen fluoride is key for the success of the reaction. 相似文献
15.
16.
17.
Ligand‐Free Palladium‐Catalyzed Aerobic Oxidative Coupling of Carboxylic Anhydrides with Arylboronic Acids 下载免费PDF全文
We report a new, effective and environmentally friendly protocol for selective aerobic oxidative coupling of arylboronic acids with carboxylic anhydrides in the presence of ligand‐free palladium catalyst. The aryl benzoates are obtained in good to excellent yields. 相似文献
18.
19.
Roxan Joncour Dr. Nicolas Susperregui Noël Pinaud Dr. Karinne Miqueu Prof. Eric Fouquet Dr. Jean‐Marc Sotiropoulos Prof. François‐Xavier Felpin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(28):9291-9296
We describe the coupling of anilines with aryl boronic acids, under ligand‐, base‐, and salt‐free conditions at room temperature. This new reaction proceeds through the formation of an aryl palladium alkoxo complex, which allows the transmetalation step with aryl boronic acids without any external base. Importantly, this sustainable procedure generates only environmentally friendly byproducts such as tBuOH, H2O, N2, and B(OH)3. The reaction mechanism has been deeply investigated through experimental and theoretical studies. 相似文献
20.
BruceH. Lipshutz BryanA. Frieman Ching‐Tien Lee Asher Lower DanielleM. Nihan BenjaminR. Taft 《化学:亚洲杂志》2006,1(3):417-429
A study involving the relatively rare combination of heterogeneous catalysis conducted under microwave conditions is presented. Carbon–carbon bond formation, including Negishi and Suzuki couplings, can be quickly effected with aryl chloride partners by using a base metal (nickel) adsorbed in the pores of activated charcoal. Aminations were also studied, along with cross‐couplings of vinyl alanes with benzylic chlorides as a means to stereodefined allylated aromatics. Reaction times for all these processes are typically reduced from several hours to minutes in a microwave reactor. 相似文献