共查询到20条相似文献,搜索用时 15 毫秒
1.
Mana Yamashita Koji Hirano Tetsuya Satoh Masahiro Miura 《Advanced Synthesis \u0026amp; Catalysis》2011,353(4):631-636
It has been found that readily available hydroxylated cinnamic acids such as ferulic acid undergo palladium‐catalyzed decarboxylative coupling with aryl iodides and internal alkynes in a 1:1:1 manner to produce 1,4‐diarylbuta‐1,3‐dienes. The butadiene synthesis has also been achieved through the coupling of aryl halides with dienoic acids. Some of the products exhibit solid‐state fluorescence. 相似文献
2.
Lutz Ackermann Rubn Vicente Robert Born 《Advanced Synthesis \u0026amp; Catalysis》2008,350(5):741-748
Generally applicable, palladium‐catalyzed direct arylations of 1,2,3‐triazoles with aryl chlorides were accomplished through conventional heating at reaction temperatures of 105–120 °C. Thereby, intra‐ and intermolecular C H bond functionalizations were achieved with a variety of differently substituted chlorides as electrophiles, bearing numerous valuable functional groups. 相似文献
3.
Dongxu Chen Xiaoyi Chen Zenghui Lu Haiting Cai Jinbei Shen Gangguo Zhu 《Advanced Synthesis \u0026amp; Catalysis》2011,353(9):1474-1478
A highly efficient and stereoselective method for the synthesis of (1Z)‐1,2‐dihalo‐3‐vinyl‐1,3‐dienes featuring palladium‐catalyzed coupling of haloalkynes and 2,3‐butadienyl acetates was developed. The resulting products were smoothly converted into cis‐1,2‐dihalostyrene derivatives using the Diels–Alder/aromatization sequence. 相似文献
4.
A ruthenium‐catalyzed oxidative homo‐coupling reaction of 2‐arylpyridines via C H activation was developed. The reaction could tolerate various functional groups on both the aryl and the pyridyl rings to afford a series of dimerized products with iron(III) chloride (FeCl3) as a stoichiometric oxidant. A tentative mechanism was proposed for this oxidative C H/C H homo‐coupling. 相似文献
5.
Fan Pu Yang Li Yong‐Hong Song Jianliang Xiao Zhong‐Wen Liu Chao Wang Zhao‐Tie Liu Jian‐Gang Chen Jian Lu 《Advanced Synthesis \u0026amp; Catalysis》2016,358(4):539-542
By using N,N‐dimethylformamide (DMF) as a methylenating reagent, the copper‐catalyzed C H activation of indole was demonstrated as an efficient and facile protocol for synthesizing 3,3′‐diindolylmethane (DIM) and its derivatives. The results indicate that copper chloride was the best catalyst among the investigated transition metal salts, which affords an excellent regioselectivity and good yield when tert‐butyl hydroperoxide (TBHP) was used as an oxidant.
6.
Carbon‐selenium and carbon‐tellurium cross‐couplings of arylboronic acids with diselenides and ditellurides have been catalyzed by iron(0), iron(II) chloride or iron(III) chloride without any ligand and additive in the air. The method yields the corresponding unsymmetrical diorgano monoselenides and monotellurides in good to excellent yields, displays a broad substrate scope, and is simple, convenient, effective, economical and environmentally friendly. 相似文献
7.
A new approach for the synthesis of novel annulated‐pyrazoles is presented. This protocol includes an intermolecular condensation followed by a copper‐mediated intramolecular C N or C O coupling reaction. The method is applied to a range of substituted 4‐iodopyrazolecarbaldehydes which react with 1,2‐phenylenediamines or 2‐aminophenols to yield substituted 2,4‐ or 1,4‐dihydrobenzo[b]pyrazolo[4,3‐e][1,4]diazepines or substituted‐2H‐ or 1H‐benzo[b]pyrazolo[3,4‐f][1,4]oxazepines, respectively. 相似文献
8.
Luca Alessandro Perego Laurence Grimaud Fabio Bellina 《Advanced Synthesis \u0026amp; Catalysis》2016,358(4):597-609
An in‐depth mechanistic study on the palladium‐catalyzed direct arylation of imidazoles at the C‐5 position is presented. The interactions of triphenylphosphine (PPh3)‐ligated aryl‐Pd species with 1,2‐dimethyl‐1H‐imidazole (dmim) have been studied in detail. In contrast with previous suggestions, phosphine‐ligated organo‐Pd species are not active and the reaction proceeds through imidazole‐ligated organo‐Pd intermediates. The kinetics of the oxidative addition of aryl halides with dmim‐ligated Pd(0) species have been characterized in a Pd(dba)2/dmim model system. A thorough study of the equilibria involving novel [ArPd(dmim)2X] complexes (X=I, OAc) and the unexpected cationic [ArPd(dmim)3]+ is also reported. The ability of these species to effect the C H arylation of dmim at room temperature in the presence of acetate is also demonstrated.
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10.
An aerobic, ligand‐free Suzuki coupling reaction catalyzed by in situ generated palladium nanoparticles in polyethylene glycol with an average molecular weight of 400 Da (PEG‐400) at room temperature has been developed. This catalytic system is a very simple and highly active protocol for the Suzuki coupling of aryl chlorides with arylboronic acids, which proceed smoothly in excellent yields in short times using low catalyst loadings. Control experiments demonstrated that the Suzuki reaction catalyzed by the in situ generated palladium nanoparticles can be carried out much quicker than that using the preprepared particles under the same conditions. The formation of palladium nanoparticles in PEG‐400 was promoted by arylboronic acids. 相似文献
11.
Venkatachalam Rajeshkumar Fu‐Wei Chan Shih‐Ching Chuang 《Advanced Synthesis \u0026amp; Catalysis》2012,354(13):2473-2483
An extraordinarily efficient hybrid acids‐assisted, palladium‐catalyzed and chelating‐group‐assisted C H bond activation of N‐sulfonyl‐2‐aminobiaryls and their annulations with [60]fullerene via sequential C C and C N bond formation at room temperature to afford [60]fulleroazepines is demonstrated. The formation of [60]fulleroazepines is highly regioselective and tolerant to both electron‐withdrawing and electron‐donating groups on the aryl moiety and the reaction gives monofunctionalized fullerenes in good yields (up to 54% isolated yield and 92% based on converted C60). 相似文献
12.
Yoshiaki Kitamura Satoko Sako Azusa Tsutsui Yasunari Monguchi Tomohiro Maegawa Yukio Kitade Hironao Sajiki 《Advanced Synthesis \u0026amp; Catalysis》2010,352(4):718-730
A ligand‐free and heterogeneous palladium on carbon (Pd/C)‐catalyzed hetero‐Suzuki–Miyaura coupling reaction has been developed. The protocol enables the construction of both heterocyclic‐alicyclic and heterocyclic‐heterocyclic biaryl derivatives in good to excellent yields. Furthermore, Pd/C could be reused. The time‐course study clarified that palladium was leached into the reaction media as the reaction proceeded and then completely deposited on the carbon support. 相似文献
13.
Nicola Della Ca' Elena Motti Antonio Mega Marta Catellani 《Advanced Synthesis \u0026amp; Catalysis》2010,352(9):1451-1454
A catalytic synthesis of selectively substituted phenanthridines is achieved through a reaction sequence involving palladium/norbornene‐catalyzed unsymmetrical aryl‐aryl and Heck couplings followed by aza‐Michael and retro‐Mannich reactions. In spite of the many steps involved the method is very simple and allows the formation of selectively substituted phenanthridines under mild conditions in a straightforward one‐pot reaction starting from readily available aryl iodides and bromides. 相似文献
14.
An umpolung approach to the synthesis of diaryl ketones has been developed based on in situ generation of acyl anion equivalents and their catalytic arylation. This method entails the base‐promoted, palladium‐catalyzed direct C‐H arylation of 2‐aryl‐1,3‐dithianes with aryl bromides. Use of MN(SiMe3)2 (M=Li, Na) base results in reversible deprotonation of the weakly acidic dithiane. In the presence of a Pd(NiXantphos)‐based catalyst and aryl bromide, cross‐coupling of the metallated 2‐aryl‐1,3‐dithiane takes place under mild conditions (2 h at rt) with yields as high as 96 %. The resulting 2,2‐diaryl‐1,3‐dithianes were converted into diaryl ketones by either molecular iodine, N‐bromo succinimide (NBS) or Selectfluor in the presence of water. The dithiane arylation/hydrolysis can be performed in a one‐pot procedure to yield a variety of diaryl ketones in good to excellent yields. This method is suitable for rapid and large‐scale synthesis of diaryl ketones. A one‐pot preparation of anti‐cholesterol drug fenofibrate (TriCor®) has been achieved on 10.0 mmol scale in 86 % yield.
15.
Laurent Djakovitch Vronique Dufaud Rabah Zaidi 《Advanced Synthesis \u0026amp; Catalysis》2006,348(6):715-724
Heterogeneous palladium catalysts ([Pd(NH3)4]2+/NaY and [Pd]/SBA‐15) were applied to the synthesis of 2‐functionalised indoles, giving generally high conversions and selectivities (>89% yield) using only 1 mol % [Pd]‐catalyst under standard reaction conditions (polar solvent, 80 °C). For the synthesis of 2,3‐functionalised indoles by cross‐coupling arylation, the [Pd]/SBA‐15 catalyst was found to be particularly interesting, producing the expected compound with =35% yield after 12 days of reaction, which is comparable to the homogeneous catalyst, Pd(OAc)2 (=48% yield). In the course of the study, the dual reactivity of the indole nucleus was demonstrated: aryl bromides gave clean C C coupling while aryl iodides led to a clean C N coupling. 相似文献
16.
The direct C H and C halogen activation for C C bond formation is one of the most interesting reactions in organic chemistry. C C bond formation using alkynes as a carbon nucleophilic source is a very useful method in synthesis. Herein, a copper(I) chloride catalyzed three‐component coupling reaction of alkynes, dihalomethanes and amines through C H and C halogen activation to form propargylic amines under mild conditions has been established. The reaction can be conducted in water, in neat or in common organic solvents and it was applicable to both aromatic and aliphatic alkynes with good functional groups tolerance. It represents an excellent example of multi‐component reactions (MCRs), provides an elegant method for the synthesis of propargylic amines which are frequent skeletal components and synthetically versatile key intermediates for the preparation of many nitrogen‐containing biologically active compounds. From the mechanism point of view, this chemistry offers not only a new approach to propargylic amines with new C C and C N bonds formation through C H and C halogen activation, but also provides valuable mechanistic insight into the novel multi‐component reactions. 相似文献
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18.
Naota Yokoyama Yuji Nakayama Hideki Nara Noboru Sayo 《Advanced Synthesis \u0026amp; Catalysis》2013,355(10):2083-2088
The well‐defined diphenylvinylphosphine‐palladium complex 1 and the diphenylcyclopropylphosphine‐palladium complex 2 were successfully synthesized. The crystal structures of these complexes were obtained by X‐ray crystallographic analysis. Both complexes were air‐ and moisture‐stable, and could be prepared on a gram scale. These palladium complexes catalyzed the Suzuki–Miyaura reaction of aryl bromides [turnover numbers (TON) up to 196,000] and aryl chlorides (TON up to 50,000). Furthermore, complex 2 catalyzed the Buchwald–Hartwig amination of aryl chlorides and aromatic/aliphatic amines with a low catalyst loading. These complexes showed different reactivities for the coupling of 2‐chloropyridine, and the origin of this difference is discussed. 相似文献
19.
Naoyuki Hoshiya Satoshi Shuto Mitsuhiro Arisawa 《Advanced Synthesis \u0026amp; Catalysis》2011,353(5):743-748
The actual active species of the recently developed sulfur‐modified, gold‐supported palladium material, S ‐modified A u‐supported Pd (SAPd), with one of the lowest Pd‐releasing levels and high recyclability in the Suzuki–Miyaura coupling, was investigated. Also, SAPd was found to work repeatedly as an excellent Pd reservoir for liquid‐phase combinatorial synthesis. 相似文献
20.
Qingwen Gui Xiang Chen Liang Hu Dadian Wang Jidan Liu Ze Tan 《Advanced Synthesis \u0026amp; Catalysis》2016,358(4):509-514
The copper‐mediated direct ortho C H bond arylation of benzamide derivatives with arylboronic acids was achieved by employing an 8‐aminoquinoline moiety as the bidentate directing group. Various biaryls were synthesized in good yields with excellent regioselectivity. The reaction shows good functional group compatibility and proceeds in a highly selective manner at the ortho‐position of the benzamides. Deuterium‐labelling experiments indicated that the ortho C H bond cleavage of benzamide was involved in the rate‐determining step of the arylation.