共查询到20条相似文献,搜索用时 15 毫秒
1.
Lin-Yan Xu Chun-Yu Liu Shi-Yuan Liu Zhi-Gang Ren David James Young Jian-Ping Lang 《Tetrahedron》2017,73(22):3125-3132
One palladium dichloride adduct of a phosphine-pyridine ligand N-diphenylphosphanyl-2-aminopyridine (L1) [(L1)PdCl2] (1) has been prepared and structurally characterized. Compound 1 can be used as an effective catalyst for the Suzuki-Miyaura cross-coupling reactions of unreactive aryl chlorides with aryl boronic acids, and worked much better than its mono- or bidentate phosphine ligands. The reactions with a wide scope of substrates proceeded to give desired products in good to excellent yields. 相似文献
2.
Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides and chlorides undergoes Suzuki cross-coupling with alkylboronic acids in good yields. Several alkyl substituents such as ethyl, n-butyl, n-octyl, isobutyl or 2,2-dimethylpropyl on the alkylboronic acids have been successfully used. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides. 相似文献
3.
Bhausaheb N. Patil Pratima A. Sathe Babasao S. Parade Kamlesh S. Vadagaonkar Atul C. Chaskar 《Tetrahedron letters》2018,59(49):4340-4343
Iodine/NaOH-catalyzed one-pot dehomologative oxidation of styrenes to aryl carboxylic acids has been reported. A wide range of carboxylic acids are obtained using iodine (I2) as a catalyst, tert-butyl hydroperoxide (TBHP) as an oxidant and sodium hydroxide (NaOH) as a base. This reliable conversion involves dehomologation of styrene to aromatic aldehyde which on subsequent oxidation affords aryl carboxylic acid. This protocol was used for gram-scale synthesis as it is free from chromatographic purification. This is the first report for the oxidative transformation of styrenes into aryl carboxylic acids under transition metal-free conditions. 相似文献
4.
An improved acylative cross-coupling of various N-methyl-N-tosyl amides with diarylborinic acids for synthesis of aryl ketones is developed. In most cases, aryl ketones could be obtained in excellent yields by using 1?mol% 2,6-diisopropylphenylimidazolylidene and 3-chloropyridine co-supported palladium chloride as catalyst in the presence of 3 equiv. K2CO3 as base in refluxing THF. The readily prepared and cost-effective substrates, N-methyl-N-tosylamides and diarylborinic acids, and the commercially available catalyst system promise a practical and efficient access to aryl ketones. 相似文献
5.
The coupling reaction of aryl chlorides with arylboronic acids was successfully performed in isopropanol (IPA) by using [NiCl(Ph2PCH2CH2OH)2(H2O)]Cl (5), a cationic Ni(II)-complex, as a precatalyst in the absence of a reducing agent. The coupling reaction proceeded smoothly under mild conditions to provide biaryls in satisfactory to excellent yields, and formation of the undesired dechlorination products of aryl chlorides was completely prevented. 相似文献
6.
An air-stable and easy-to-handle nickel precatalyst, (9-phenanthrenyl)Ni(II)(PPh3)2Cl, was examined for the cross-coupling reactions of aryl tosylates with arylboronic acids. Under the optimized reaction conditions, the catalytic system tolerates a wide range of activated, neutral and deactivated substrates. The selectivity of this cross-coupling reaction towards aryl tosylates and arylboronic acids has been investigated. It is proposed that ligand 1,1′-bis(diphenylphosphino)ferrocene (dppf) plays a key role in the coupling by enforcing a cis geometry in key intermediates and the active Ni(0) species. 相似文献
7.
Xiao-Feng Wu 《Tetrahedron letters》2010,51(47):6146-6149
A novel chemoselective protocol for the carbonylative Suzuki coupling of benzyl chlorides with aryl boronic acids at low pressure of carbon monoxide has been developed. Applying a commercially available palladium acetate/PCy3 catalyst system in the presence of potassium phosphate as the base and water as the solvent the coupling reactions proceeded smoothly. To demonstrate the general applicability 12 different α-arylated acetophenones have been synthesized in moderate to good yields (41-78%) under mild conditions. 相似文献
8.
An efficient copper-catalyzed cross-coupling of aryl iodides with aryl acetylenes under microwave irradiation is described. The reaction proceeds under microwave heating with 10 mol % CuI and 2 equiv Cs2CO3 in 43-87% yields. 相似文献
9.
The atom-efficient cross-coupling of triarylbismuths with aryl iodides or aryl triflates using catalytic Pd(OAc)2/PPh3 and K3PO4 as base in DMF at 90 °C to afford the corresponding functionalized biaryls in high yields is reported. 相似文献
10.
Through the use of [PdCl(C3H5)]2/Cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides undergoes Heck reaction with acrolein ethylene acetal. With this acetal, the selective formation of 3-arylpropionic acids/esters was observed. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides. 相似文献
11.
《Tetrahedron letters》2014,55(50):6799-6802
An efficient approach to aryl azides, in short reaction times and good to excellent yields, has been developed via the reaction of aryl halides with sodium azide under Cu2O/tetraethylammonium prolinate catalysis. 相似文献
12.
Xubo Qin Changjun Chen Lingjuan Zhang Jianbin Xu Yixiao Pan Haoqiang Zhao Jiahong Han Huanrong Li Lijin Xu 《Tetrahedron》2017,73(16):2242-2249
Palladium(II)-catalyzed highly regioselective and stereoselective decarboxylative arylation of unactivated olefins with aryl carboxylic acids has been developed. This method is applicable to a variety of unactivated olefins, including allylamides, long chain functionalized olefins and purely aliphatic olefins, leads to the formation of linear E-configured products in high yields. Both electron-rich and electron-deficient aryl carboxylic acids are suitable arylation reagents. It was found that the choice of solvent, catalyst precursor and oxidant had an important influence on reaction efficiency. As a co-solvent and ligand, DMSO is critical to catalysis. This chemistry expands the scope of decarboxylative arylation of olefins with aryl carboxylic acids, and provides a rapid access to useful linear arylation products of unactivated olefins. 相似文献
13.
Three new aryl sulphonylacetic acids have been prepared from 2-chlorotoluene, 1,2-dichlorobenzene and 1-bromonaphthalene.
The infrared spectra of these acids exhibited strong bands characteristic of carbonyl stretching frequencies of carboxylic
acids. Utilising these sulphonylacetic acids some new unsaturated sulphones were synthesised. An attempt has been made to
correlate the infrared and proton magnetic resonance spectral data to the configurations of unsaturated sulphones. 相似文献
14.
Zhengjiang Fu Yongqing Jiang Ligao Jiang Zhaojie Li Shengmei Guo Hu Cai 《Tetrahedron letters》2018,59(51):4458-4461
A simple and practical Cu-catalyzed decarboxylative iodination has been well established under aerobic condition, which provides a useful method to synthesize aryl iodides in moderate to good yields with the use of (hetero)aryl carboxylic acids and NaI as starting materials. Thiabendazole has been prepared via a three-step procedure to show synthetic practicability of the protocol. 相似文献
15.
Surendra Harkal Dirk Michalik Ralf Jackstell Thomas Riermeier Matthias Beller 《Tetrahedron letters》2005,46(18):3237-3240
The combination of 2-phosphino-substituted N-arylpyrroles or related indoles (cataCXium®P) and Pd(OAc)2 allows for efficient cross-coupling reactions of aryl chlorides and phenols to give diaryl ethers. A variety of aryl and heteroaryl chlorides can be coupled with substituted phenols showing unprecedented catalyst turnover numbers. 相似文献
16.
Jeongju Moon 《Journal of organometallic chemistry》2009,694(3):473-1041
The catalytic system based on Pd-phosphite for the dehalogenation reactions of aryl chlorides and bromides is described. The Pd-phosphite catalyst effectively promoted the dehalogenation of aryl halides to give dehalogenated products in moderate to excellent yields. The aryl chlorides required strong bases such as NaOtBu for this transformation, whereas the aryl bromides were dehalogenated in the presence of weak bases such as Cs2CO3. This catalytic system exhibited tolerance to functional groups such as methoxy, amine, hydroxyl, ether, amide, benzyl and ketone groups. It also demonstrated chemoselectivity in that bromochlorobenzene was converted only to chlorobenzene. 相似文献
17.
B.V. Subba Reddy N. Sivasankar ReddyY. Jayasudhan Reddy Y. Vikram Reddy 《Tetrahedron letters》2011,52(20):2547-2549
Aryl azides react smoothly with aryl boronic acids in the presence of indium metal in methanol to furnish a variety of unsymmetrical diaryl amines in good yields. This is the first report on the synthesis of diaryl amines from the cross coupling of aryl azides with aryl boronic acids via N-arylation. 相似文献
18.
Linda Axelsson Jean-Baptiste VeronJonas Sävmarker Jonas LindhLuke R. Odell Mats Larhed 《Tetrahedron letters》2014
A palladium(II)-catalyzed decarboxylative protocol for the synthesis of aryl ketones has been developed. The addition of TFA was shown to improve the reaction yield and employing THF as solvent enabled the use of solid nitriles and in only a small excess. Using this method, five different benzoic acids reacted with a wide range of nitriles to produce 29 diverse (hetero)aryl ketone derivatives in up to 94% yield. 相似文献
19.
The general procedure for the rhodium-catalyzed cross-coupling of thiols with aryl iodides is described. The catalytic system consists of 5 mol % of [RhCl(cod)]2 and 10 mol % of PPh3 as a ligand. A variety of aryl iodides reacted with thiols, giving aryl thioethers in good to excellent yields. It is important to note that the deactivated aryl iodides such as 4-iodoanisole is worked smoothly to provide the corresponding aryl thioethers in excellent yields. Functional groups such as free-amines, chloro, are all tolerated under the employed reaction conditions. 相似文献
20.
Yoshiaki Nakao 《Journal of organometallic chemistry》2003,687(2):570-573
Triallyl(aryl)silanes, stable and easily accessible arylsilanes, were found to react with aryl bromides in the presence of a palladium catalyst (PdCl2-PCy3) and tetrabutylammonium fluoride (TBAF) in good yields. The scope of the reaction is broad, and a wide variety of functional groups are tolerant. Allyl groups on Si are readily cleaved upon treatment with TBAF to form fluorosilanes, silanepolyols, siloxanes and/or their mixed forms, which might be responsible for high efficiency of the reaction. 相似文献