共查询到20条相似文献,搜索用时 15 毫秒
1.
Anne Brennführer Helfried Neumann Dr. Matthias Beller Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(23):4114-4133
A CO group richer : (Hetero)arenes are vital intermediates in the manufacture of agrochemicals, dyes, pharmaceuticals, and other industrial products. In the past decades transition‐metal‐catalyzed coupling reactions of aryl halides with all types of nucleophiles have been developed. This Review summarizes recent work in the area of palladium‐catalyzed carbonylation reactions of aryl halides and related compounds (see scheme).
2.
Dr. Chandra M. R. Volla Dr. Javier Mazuela Prof. Dr. Jan‐E. Bäckvall 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(25):7608-7612
A highly efficient oxidative carbocyclization–carbonylation reaction cascade of allenynes and enallenes has been developed using a PdII salt in low catalytic amounts under ambient temperature and pressure (1 atm of carbon monoxide). The use of DMSO as an additive was found to be important for an efficient reaction. A wide range of alcohols as trapping reagents were used to give the corresponding esters in good yields. 相似文献
3.
Silver‐Triggered Activity of a Heterogeneous Palladium Catalyst in Oxidative Carbonylation Reactions
Man‐Bo Li Ying Yang Abdolrahim A. Rafi Michael Oschmann Erik Svensson Grape A. Ken Inge Armando Crdova Jan‐E. Bckvall 《Angewandte Chemie (International ed. in English)》2020,59(26):10391-10395
A silver‐triggered heterogeneous Pd‐catalyzed oxidative carbonylation has been developed. This heterogeneous process exhibits high efficiency and good recyclability, and was utilized for the one‐pot construction of polycyclic compounds with multiple chiral centers. AgOTf was used to remove chloride ions in the heterogeneous catalyst Pd‐AmP‐CNC, thereby generating highly active PdII, which results in high efficiency of the heterogeneous catalytic system. 相似文献
4.
5.
Synthesis of 2‐Alkynoates by Palladium(II)‐Catalyzed Oxidative Carbonylation of Terminal Alkynes and Alcohols 下载免费PDF全文
Qun Cao N. Louise Hughes Dr. Mark J. Muldoon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(34):11982-11985
A homogeneous PdII catalyst, utilizing a simple and inexpensive amine ligand (TMEDA), allows 2‐alkynoates to be prepared in high yields by an oxidative carbonylation of terminal alkynes and alcohols. The catalyst system overcomes many of the limitations of previous palladium carbonylation catalysts. It has an increased substrate scope, avoids large excesses of alcohol substrate and uses a desirable solvent. The catalyst employs oxygen as the terminal oxidant and can be operated under safer gas mixtures. 相似文献
6.
Synthesis of New Diphosphine Ligands and their Application in Pd‐Catalyzed Alkoxycarbonylation Reactions 下载免费PDF全文
Dr. Anahit Pews‐Davtyan Xianjie Fang Dr. Ralf Jackstell Dr. Anke Spannenberg Dr. Wolfgang Baumann Prof. Dr. Robert Franke Prof. Dr. Matthias Beller 《化学:亚洲杂志》2014,9(4):1168-1174
Carbocyclic and N‐heterocyclic analogues of the industrially applied ligand bis(di‐tert‐butylphosphinomethyl)benzene ( 1 ) have been synthesized in moderate to very good yields. The new ligands are based on benzene, tetralin, lutidine, pyrazine, quinoxaline, and maleimide backbones. Electronic and steric variations of the phosphorous donor sites were performed. As a benchmark reaction, the palladium‐catalyzed methoxycarbonylation of 1‐octene has been tested. Ester yields up to 64 % and high linear selectivities up to 92 % were achieved. 相似文献
7.
8.
Ming Chen Xucai Wang Pengfei Yang Xun Kou Zhi‐Hui Ren Zheng‐Hui Guan 《Angewandte Chemie (International ed. in English)》2020,59(29):12199-12205
Reported herein is the development of the first enantioselective monodentate ligand assisted Pd‐catalyzed domino Heck carbonylation reaction with CO. The highly enantioselective domino Heck carbonylation of N‐aryl acrylamides and various nucleophiles, including arylboronic acids, anilines, and alcohols, in the presence of CO was achieved. A novel monodentate phosphoramidite ligand, Xida‐Phos, has been developed for this reaction and it displays excellent reactivity and enantioselectivity. The reaction employs readily available starting materials, tolerates a wide range of functional groups, and provides straightforward access to a diverse array of enantioenriched oxindoles having β‐carbonyl‐substituted all‐carbon quaternary stereocenters, thus providing a facile and complementary method for the asymmetric synthesis of bioactive hexahydropyrroloindole and its dimeric alkaloids. 相似文献
9.
10.
Palladium‐Catalyzed Carbonylative Reactions of 1‐Bromo‐2‐fluorobenzenes with Various Nucleophiles: Effective Combination of Carbonylation and Nucleophilic Substitution 下载免费PDF全文
Jianbin Chen Dr. Kishore Natte Dr. Helfried Neumann Prof. Xiao‐Feng Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(49):16107-16110
A systematic study on the carbonylative transformation of 1‐bromo‐2‐fluorobenzenes with various nucleophiles has been performed. Different types of double nucleophiles, such as N?N, N?C, O?C, and N?S, can be effectively applied as coupling partners. The corresponding six‐membered heterocycles were isolated in moderate to good yields. 相似文献
11.
Prof. Dr. Daniel Solé Dr. Israel Fernández Prof. Dr. Miguel A. Sierra 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(22):6950-6958
The factors that control the chemoselectivity of palladium‐catalyzed cyclization reactions of (2‐iodoanilino)carbonyl compounds have been explored by an extensive experimental computational (DFT) study. It was found that the selectivity of the process, that is, the formation of fused six‐ versus five‐membered rings, can be controlled by the proper selection of the initial reactant, reaction conditions, and additives. Thus, esters or amides produce ketones by a nucleophilic addition process, whereas the addition of PhO? ions leads to the formation of indolines by an α‐arylation reaction. In contrast, the corresponding ketone reactants yield a mixture of both reaction products, the ratio of which depends on the base used, in the presence of phenol. The outcome of the processes can be explained by the formation of a common four‐membered palladacycle intermediate from which the competitive nucleophilic addition and α‐arylation reactions occur. The remarkable effect of phenol in the process, which makes the α‐arylation reaction easier, favored the formation of enol complexes, which are stabilized by an intramolecular hydrogen bond between the hydroxy group of the enol moiety and the oxygen atom of the phenoxy ligand. Moreover, the chemoselectivy of the process can be also controlled by the addition of bidendate ligands that lead to the almost exclusive formation of indoles at expenses of the corresponding alcohols. 相似文献
12.
Qin Xiong Dongdong Xu Chunhui Shan Song Liu Yixin Luo Fenru Liu Shihan Liu Yu Lan Ruopeng Bai 《化学:亚洲杂志》2019,14(5):655-661
Palladium (Pd)‐catalyzed radical oxidative C?H carbonylation of alkanes is a useful method for functionalizing hydrocarbons, but there is still a lack of understanding of the mechanism, which restricts the application of this reaction. In this work, density functional theory (DFT) calculations were carried out to study the mechanism for a Pd‐catalyzed radical esterification reaction. Two plausible reaction pathways have been proposed and validated by DFT calculations. The computational results reveal that the generated alkyl radical prefers to add to the carbon monoxide (CO) molecule to form a carbonyl radical before bonding with the Pd species. Radical addition onto Pd followed by CO migratory insertion was unfavorable owing to the high energy barrier of the migratory insertion step. The regioselectivity of the C(sp3)?H carbonylation was also investigated by DFT. The results show that the regioselectivity is controlled by both the bond dissociation energy of the reacting C?H bond and the stability of the corresponding generated carbon radical. Competitive side reactions also affected the yield and regioselectivity owing to the rapid consumption of the stable radical intermediate. 相似文献
13.
14.
Haoquan Li Dr. Helfried Neumann Prof. Dr. Matthias Beller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):10050-10056
A benign and efficient palladium‐catalyzed aminocarbonylation reaction of allylic alcohols is presented. The generality of this novel process is demonstrated by the synthesis of β,γ‐unsaturated amides including aliphatic, cinnamyl, and terpene derivatives. The choice of ligand is crucial for optimal carbonylation processes: Whereas in most cases the combination of PdCl2 with Xantphos ( L6 ) gave best results, sterically hindered substrates performed better in the presence of simple triphenylphosphine ( L10 ), and primary anilines gave the best results using cataCXium® PCy ( L8 ). The reactivity of the respective catalyst system is significantly enhanced by addition of small amounts of water. Mechanistic studies and control experiments revealed a tandem allylic alcohol amination/C?N bond carbonylation reaction sequence. 相似文献
15.
Xiaolong Fu Yonggang Zhen Zhenjie Ni Yang Li Huanli Dong Jay S. Siegel Wenping Hu 《Angewandte Chemie (International ed. in English)》2020,59(33):14024-14028
Aromatic diimides are one of the most important chromophores in the construction of n‐type organic semiconductors, which lag far behind their p‐type counterpart but are necessary for ambipolar transistors, p‐n junctions and organic complementary circuits. Herein, we establish a facile one‐pot domino synthetic protocol for aromatic diimides via palladium‐catalyzed carbonylation of tetrabromo aromatic precursors. Taking tetrabromocorannulene (TBrCor) and tetrabromo‐2,7‐di‐tert‐butylpyrene (TBrPy) as the typical examples, we obtained diimide derivatives in yields of about 50 %, one order of magnitude higher than that of the traditional multi‐step diimidization. As demonstrated in the case of corannulene diimide, the efficient diimidization not only allows the LUMO levels to be lowered significantly but also provides an ordered and closer packing structures, opening up possibilities to the development of n‐type semiconducting materials based on a variety of aromatic systems. 相似文献
16.
17.
Haoquan Li Dr. Wanfang Li Dr. Anke Spannenberg Dr. Wolfgang Baumann Dr. Helfried Neumann Prof. Dr. Matthias Beller Prof. Dr. Xiao‐Feng Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(28):8541-8544
Combining commercially available bromoanilines and bromobenzonitriles in a novel double carbonylation process allows for a straightforward synthesis of isoindolo[1,2‐b]quinazoline‐10,12‐diones. At least five different C?C and/or C?N bonds are selectively formed in this 3‐component reaction, which likely proceeds through sequential carbonylation–cyclization–isomerisation–carbonylation steps. Notably, two molecules of CO are inserted in this highly efficient palladium‐catalyzed process. 相似文献
18.
19.
Javier Mazuela Alexander Paptchikhine Päivi Tolstoy Oscar Pàmies Dr. Montserrat Diéguez Dr. Pher G. Andersson Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(2):620-638
A new class of modular P,N‐ligand library has been synthesized and screened in the Pd‐catalyzed allylic substitution reactions of several substrate types. These series of ligands can be prepared efficiently from easily accessible hydroxyl–oxazole/thiazole derivatives. Their modular nature enables the bridge length, the substituents at the heterocyclic ring and in the alkyl backbone chain, the configuration of the ligand backbone, and the substituents/configurations in the biaryl phosphite moiety to be easily and systematically varied. By carefully selecting the ligand components, therefore, high regio‐ and enantioselectivities (ee values up to 96 %) and good activities are achieved in a broad range of mono‐, di‐, and trisubstituted linear hindered and unhindered substrates and cyclic substrates. The NMR spectroscopic and DFT studies on the Pd–π‐allyl intermediates provide a deeper understanding of the effect of ligand parameters on the origin of enantioselectivity. 相似文献