共查询到20条相似文献,搜索用时 46 毫秒
1.
New, sterically demanding 1,3‐dialkylbenzimidazolium salts ( 2a–c ) as N‐heterocyclic‐carbene precursors have been synthesized and characterized. The ortho position of aromatic aldehydes was directly and selectively arylated with aryl chlorides in the presence of a catalytic system prepared in situ from Pd(OAc)2, 1,3‐dialkylbenzimidazolium chlorides ( 2a–c ), and Cs2CO3. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:569–574, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20479 相似文献
2.
Takumi Kataishi Kotaro Kato Yoshiaki Makihara Yuichi Kitashima Sigeru Ohara Fumiaki Anzai Seiich Inokuma Hiroyuki Oku Masa‐aki Ubukata Yutaka Takahashi Taichi Nakano 《应用有机金属化学》2008,22(12):665-670
A combination catalyst of Pd(dba)2‐PPh3‐CuI‐LiCl or Pd(dba)2‐P(2‐furyl)3‐CuI‐LiCl effectively catalyzed the cross‐coupling of (Z)‐germyl(stannyl)ethenes with aryl halides, providing novel triethyl(2,2‐diarylethenyl)germanes in good to high yields. The reaction proceeds with retention of configuration. Cross‐coupling results in the formation of phenylene or phenyleneethynylene derivatives with terminal stereochemically defined vinylgermane unit(s). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
3.
Xiaojie Zhang Yao Gao Sida Li Xincui Shi Yanhou Geng Fosong Wang 《Journal of polymer science. Part A, Polymer chemistry》2014,52(16):2367-2374
Poly(5,6‐difluoro‐2,1,3‐benzothiadiazole‐alt‐9,9‐dioctylfluorene) was successfully synthesized via direct arylation polycondensation of 5,6‐difluoro‐2,1,3‐benzothiadiazole and 2,7‐dibromo‐9,9‐dioctylfluorene. The reaction conditions were optimized, and a polymer with number‐average molecular weight (Mn) of 41,000 was obtained by using Pd(OAc)2, PtBu2Me‐HBF4, pivalic acid, K2CO3, and toluene as catalyst, ligand, additive, base, and solvent, respectively. The polycondensation was also performed with 5,6‐dioctyloxy‐2,1,3‐benzothiadiazole or 2,1,3‐benzothiadiazole as the comonomer, and the results indicate that the introduction of electron‐withdrawing fluorine atoms at the ortho‐positions to the C? H bonds is essential for the reactivity of the direct arylation. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2367–2374 相似文献
4.
Phosphine‐free direct arylation synthesis and self‐assembled nanostructure analysis of poly(3‐hexylselenophene) 下载免费PDF全文
Kazuhiro Nakabayashi Naoto Otsuki Hideharu Mori 《Journal of polymer science. Part A, Polymer chemistry》2017,55(17):2749-2755
Poly(3‐hexylselenophene)s (P3Hs) with high regioregularity (RR = 92–96%), that is, regioregular poly(3‐hexylselenophene)s (rr‐P3HSs), have been synthesized under the phosphine‐free direct arylation conditions in the presence of PdCl2 as a precatalyst. rr‐P3HS with the high molecular weight (Mn ~ 10,000) was obtained as a result of screening of direct arylation conditions. Subsequently, the influences of primary structure, molecular weight (Mn = 3900–10,000) and regioregularity (RR = 57–96%), on optical properties and self‐assembled nanostructure of P3HS were investigated. X‐ray diffraction demonstrated that molecular weight, regioregularity, and preparation method of films dominate the crystallization behavior of P3HS. Among these parameters, it was evident that a high degree of regioregularity was the most fundamental contributor to achieve pure crystalline nanostructure. Furthermore, nanoassembly based on pure crystalline nanostructure, such as non‐woven fibrous and bundle‐like spherulitic self‐assembled nanostructures, was successfully prepared in rr‐P3HS, respectively, by appropriate modulation of the aforementioned parameters. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2749–2755 相似文献
5.
Kilho Yu Ahmed Elbarbary Kwanghee Lee Jae‐Suk Lee 《Journal of polymer science. Part A, Polymer chemistry》2014,52(20):2926-2933
A series of three new low bandgap donor–acceptor–donor–acceptor/ (D–A–D–A/) polymers have been successfully synthesized based on the combination of isoindigo as the electron‐deficient acceptor and 3,4‐ethylenedioxythiophene as the electron‐rich donor, followed by CH‐arylation with different acceptors (4,7‐dibromo[c][1,2,5]‐(oxa, thia, and/or selena)diazole ( 4a‐c )). These polymers were used as donor materials for photovoltaic applications. All of the polymers are highly stable and show good solubility in chlorinated solvents. The highest power conversion efficiency of 1.6% was achieved in the bulk heterojunction photovoltaic device that consisted of poly ((E)?6‐(7‐(benzo‐[c][1,2,5]‐thiadiazol‐4‐yl)?2,3‐dihydrothieno‐[3,4‐b][1,4]dioxin‐5‐yl)?6′‐(2,3‐dihydrothieno‐[3,4‐b][1,4]‐dioxin‐5‐yl)?1,1′‐bis‐(2‐octyldodecyl)‐[3,3′‐biindolinylidene]‐2,2′‐dione) as the donor and PC61BM as the acceptor, with a short‐circuit current density (Jsc) of 8.10 mA/cm2, an open circuit voltage (Voc) of 0.56 V and a fill factor of 35%, which indicates that these polymers are promising donors for polymer solar cell applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2926–2933 相似文献
6.
Palladium‐catalyzed direct arylation of polyfluoroarene and facile synthesis of liquid crystal compounds 下载免费PDF全文
A convenient approach has been developed to prepare polyfluorobiphenyl by Pd(OAc)2/PCy3‐catalyzed direct arylation of polyfluoroarenes with aromatic halides in the presence of Cs2CO3 as base and toluene as solvent. In most cases, the desired arylated products of aromatic bromides were obtained in good to excellent yield at 80°C, and aryl chlorides also gave modest to good yields of arylated products at 110°C. According to this efficient C―C bondforming method, polyfluorobiphenyl liquid crystal compounds were prepared by Pd‐catalyzed direct arylation reactions of polyfluoroarenes with long alkyl chain substituted aryl bromides in 62–96% yield. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
7.
Qiang Zhang Chun‐Mei Xu Jiu‐Xi Chen Xiao‐Ling Xu Jin‐Chang Ding Hua‐Yue Wu 《应用有机金属化学》2009,23(12):524-526
A palladium‐catalyzed coupling‐type reaction of arylglyoxals with arylboronic acids was achieved by use of trimesitylphosphine as the ligand and K2CO3 as base in toluene, providing symmetrical and unsymmetrical benzil derivatives with yields ranging from moderate to excellent. Of particular mention, the rigorous exclusion of air and moisture is not required in these transformations. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
8.
Direct arylation polymerization toward a narrow bandgap donor–acceptor conjugated polymer of alternating 5,6‐difluoro‐2,1,3‐benzothiadiazole and alkyl‐quarternarythiophene: From synthesis,optoelectronic properties to devices 下载免费PDF全文
Amsalu Efrem Kai Wang Tao Jia Mingfeng Wang 《Journal of polymer science. Part A, Polymer chemistry》2017,55(11):1869-1879
ABSTRACT: Direct arylation polymerization (DAP) enabled facile synthesis of a narrow bandgap donor–acceptor conjugated polymer (PDFBT‐Th4) composed of alternating 5,6‐difluoro‐2,1,3‐benzothiadiazole and alkyl‐quaternarythiophene. The optimized reaction condition of DAP catalyzed with Pd(OAc)2/(o‐MeOPh)3P/PivOH/K2CO3 in o‐xylene led to the target polymer with a number‐average molecular weight (Mn) of 14.6 kDa without noticeable homocoupling or β‐branching defects. UV‐vis absorption spectra of PDFBT‐Th4 indicate strong interchain aggregation in films. While the C‐H selectivity and the alternating polymer structure of PDFBT‐Th4 synthesized via DAP are comparable to those of the same type polymers synthesized via Stille coupling, the batch of PDFBT‐Th4 synthesized via optimal DAP, despite its lower Mn, showed higher hole mobility in field effect transistors and larger power conversion efficiency in organic solar cell devices. These results further demonstrate the promising potential of DAP for efficient synthesis of high‐performance D‐A conjugated polymers for broad optoelectronic applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1869–1879 相似文献
9.
Xiang Zhang 《International journal of quantum chemistry》2015,115(23):1658-1667
The radical arylation of the para‐substituted anilines under three different conditions (A: arylhydrazines as the radical precursors and MnO2 as the oxidant in acetonitrile; B: arylhydrazine hydrochlorides as the radical precursors and O2 as the oxidant in aqueous sodium hydroxide solution; C: arenediazonium salts as the radical precursors and TiCl3 as the reductant in aqueous hydrochloric acid solution) has been theoretically studied and the origins of the ortho/meta regioselectivity have been explored. The arylation process is suggested to contain three steps: radical generation, radical addition, and rearomatization. Calculations show that the arylation of the neutral anilines is kinetically controlled under conditions A and B, and the regioselectivity is determined by the radical addition. As a directing group, ? NH2 plays an important role in these cases with the assistance of Mn(OH)2 (the reduced product of MnO2 under condition A) and Na+ (condition B). As for the arylation of the protonated anilines under condition C, the regioselectivity is affected by the substituents in the para‐position of anilines. Electron‐donating groups support meta‐addition and the selectivity is decided by the radical addition. Conversely, electron‐withdrawing groups favor ortho‐addition, and in this situation the arylation process is thermodynamically controlled and the regioselectivity is determined by the radical addition and rearomatization. © 2015 Wiley Periodicals, Inc. 相似文献
10.
Fe3O4@SiO2 nanoparticles was functionalized with a binuclear Schiff base Cu(II)‐complex (Fe3O4@SiO2/Schiff base‐Cu(II) NPs) and used as an effective magnetic hetereogeneous nanocatalyst for the N‐arylation of α‐amino acids and nitrogen‐containig heterocycles. The catalyst, Fe3O4@SiO2/Schiff base‐Cu(II) NPs, was characterized by Fourier transform infrared (FTIR) and ultraviolet‐visible (UV‐vis) analyses step by step. Size, morphology, and size distribution of the nanocatalyst were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and dynamic light scatterings (DLS) analyses, respectively. The structure of Fe3O4 nanoparticles was checked by X‐ray diffraction (XRD) technique. Furthermore, the magnetic properties of the nanocatalyst were investigated by vibrating sample magnetometer (VSM) analysis. Loading content as well as leaching amounts of copper supported by the catalyst was measured by inductive coupled plasma (ICP) analysis. Also, thermal studies of the nanocatalyst was studied by thermal gravimetric analysis (TGA) instrument. X‐ray photoelectron spectroscopy (XPS) analysis of the catalyst revealed that the copper sites are in +2 oxidation state. The Fe3O4@SiO2/Schiff base‐Cu(II) complex was found to be an effective catalyst for C–N cross‐coupling reactions, which high to excellent yields were achieved for α‐amino acids as well as N‐hetereocyclic compounds. Easy recoverability of the catalyst by an external magnet, reusability up to eight runs without significant loss of activity, and its well stability during the reaction are among the other highlights of this catalyst. 相似文献
11.
Interaction of chitosan (CS) with Fe3O4, followed by embedding Cu nanoparticles (NPs) on the magnetic surface through adsorption of Cu2+, and its reduction to Cuo via NaBH4, offers a reusable efficient catalyst (Fe3O4/CS‐Cu NPs) that is employed in cross‐coupling reactions of aryl halides with phenols, which affords the corresponding diaryl ethers, with good to excellent yields. The catalyst is completely recoverable from the reaction mixture by using an external magnet. It can be reused four times, without significant loss in its catalytic activity. 相似文献
12.
Sabrina M. Nobre Mauro N. Muniz Marcus Seferin Wagner M. da Silva Adriano L. Monteiro 《应用有机金属化学》2011,25(4):289-293
We have developed a sequential and selective Pd‐catalyzed double‐Heck arylation of ethylene that results in non‐symmetrical nitro‐stilbene analogs of trans‐resveratrol at excellent yields. A catalytic system consisting of Pd(OAc)2 and P(o‐tolyl)3 permitted us to carry out the two consecutive Heck arylations without losing activity from the first to the second Heck reaction. After the first Heck arylation of ethylene, no isolation or additional catalyst loading is required for the second Heck arylation reaction. This protocol was applied to the synthesis of methylated trans‐resveratrol, which was obtained at a 65% overall yield. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
13.
Andrey E. Rudenko Calvin A. Wiley John F. Tannaci Barry C. Thompson 《Journal of polymer science. Part A, Polymer chemistry》2013,51(12):2660-2668
Direct arylation polymerization (DArP) is an emerging alternative to Stille and Suzuki polymerizations. This method is attractive as it allows preparation of high‐molecular‐weight conjugated polymers in good yield without the need to metallate monomers. Despite this promise, for poly(3‐hexylthiophene) (P3HT) and related polymers that have β‐protons on the thiophene ring, DArP is known to produce β‐defects, which make the polymer properties different from polymers produced by traditional methods. Here, we demonstrate that DArP conditions based on simple, inexpensive, and bench‐stable reagents can be tuned to limit the amount of defects and produce P3HT with properties remarkably similar to Stille P3HT. Specifically, lowering the reaction temperature, lowering the amount of catalyst, and using a bulkier carboxylate ligand is critical. Optimized conditions include reacting 2‐bromo‐3‐hexylthiophene with 0.25 mol % of Pd(OAc)2, 1.5 equivalents of K2CO3, and 0.3 equivalents of neodecanoic acid in N,N‐dimethylacetamide at 70 °C and give DArP P3HT with ~60% yield, regioregularity of 93.5%, molecular weight of 20 kDa, polydispersity of 2.8, and melting point of 217 °C, providing a very close match to Stille P3HT, which is obtained with 70–80% yield, 91–94% regioregularity, molecular weight of 15–25 kDa, polydispersity of 2.5–2.8, and melting point of 214–221 °C. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2660–2668 相似文献
14.
Hye Mi Oh Ji Eun Park Jisu Kim Ju Hyun Kim Prof. Youn K. Kang Prof. Young Keun Chung 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(29):9024-9036
A method for the synthesis of bicyclo[4.1.0]heptenes from 1,6‐enynes through Pd‐catalyzed cycloisomerization has been developed. N‐ and O‐tethered 1,6‐enynes were successfully transformed to their corresponding 3‐aza‐ and 3‐oxabicyclo[4.1.0]heptenes in reasonable‐to‐high yields using the catalysts [PdCl2(CH3CN)2]/P(OPh)3 or [Pd(maleimidate)2(PPh3)2] in toluene. The computational calculations using density functional theory indicate that [PdCl2{P(OPh)3}] in the oxidation state PdII acts as the active catalyst species for the formation of 3‐azabicyclo[4.1.0]heptenes through 6‐endo‐dig cyclization. 相似文献
15.
Samir Messaoudi 《Tetrahedron letters》2011,52(21):2687-2691
The selective synthesis of N-(hetero)aryl-1-aminoindoles 3 from the corresponding N-aminoindoles and (hetero)aryl halides using a catalyst combination of Pd2(dba)3 associated to Josiphos is described. By switching to Xantphos as the ligand, the alternate catalytic system allows the coupling to proceed efficiently for the preparation of symmetrical and unsymmetrical N,N′-diaryl-1-aminoindole derivatives in good yields. 相似文献
16.
Catalytic activities in direct arylation of novel palladium N‐heterocyclic carbene complexes 下载免费PDF全文
Eight novel palladium N‐heterocyclic carbene (Pd‐NHC) complexes were synthesized by the reaction of chloro 1,3‐dialkylbenzimidazolin‐2‐ylidene silver(I) complexes with bis(benzonitrile)palladium(II) chloride in dichloromethane. These eight Pd‐NHC complexes are as follows: bis[1‐phenyl‐3‐(2,4,6‐trimethylbenzyl)benzimidazol‐2‐ylidene]dichloropalladium(II), bis[1‐phenyl‐3‐(2,3,5,6‐tetramethylbenzyl)benzimidazol‐2‐ylidene]dichloropalladium(II), bis[1‐phenyl‐3‐(2,3,4,5,6‐pentamethylbenzyl)benzimidazol‐2‐ylidene]dichloropalladium(II), bis[1‐phenyl‐3‐(3,4,5‐trimethoxybenzyl)benzimidazol‐2‐ylidene]dichloropalladium(II), bis[1‐(2‐diethylaminoethyl)‐3‐(3‐methylbenzyl)benzimidazol‐2‐ylidene]dichloropalladium(II), bis[1‐(2‐diethylaminoethyl)‐3‐(2,3,5,6‐tetramethylbenzyl)benzimidazol‐2‐ylidene]dichloropalladium(II), bis[1‐(2‐morpholinoethyl)‐3‐naphthalenomethylbenzimidazol‐2‐ylidene]dichloropalladium(II) and bis[1‐(2‐morpholinoethyl)‐3‐(2‐methylbenzyl)benzimidazol‐2‐ylidene]dichloropalladium(II). Also, these synthesized complexes were fully characterized using Fourier transform infrared, 1H NMR and 13C NMR spectroscopic methods and elemental analysis techniques. These synthesized novel Pd‐NHC complexes were tested as catalysts in the direct arylation of 2‐n‐butylthiophene, 2‐n‐butylfuran and 2‐isopropylthiazole with various aryl bromides at 130°C for 1 h. The complexes showed very good catalytic activities in these reactions. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
17.
Formation of C(sp2)–X bonds was carried out using a Fe3O4@SiO2‐copper(I) sucrose xanthate nanoparticle catalyst with the aid of the copper(I) xanthate moiety in the catalyst which was prepared from the reaction between sucrose and carbon disulfide through an alkaline medium via the traditional Zeise approach. Various techniques were employed for the characterization of these novel nanoparticles. Three sorts of heteroatoms, N, O and S, successfully underwent heteroatom arylation to produce secondary or tertiary amines, ethers and thioethers, respectively. 相似文献
18.
Chuan‐Yien Liu Hsin‐Ta Wang Wen‐Chun Chung Yi‐Ting Cheng Yi‐Ting Chen Mei‐Lin Ho Chih‐Chieh Wang Gene‐Hsiang Lee Hwo‐Shuenn Sheu 《中国化学会会志》2012,59(9):1070-1079
Three coordination polymers, {[Cd(3‐bpd)2(NCS)2]×C2H5OH}n ( 1 ), {[Cd(3‐bpd)(dpe)(NO3)2]×(3‐bpd)}2 ( 2 ), {[Cd(dpe)2(NCS)2]×3‐bpd×2H2O}n ( 3 ) (3‐bpd = 1,4‐bis(3‐pyridyl)‐2,3‐diaza‐1,3‐butadiene; dpe = 1,2‐bis(4‐pyridyl)ethane), were prepared and structurally characterized by a single‐crystal X‐ray diffraction method. In compound 1 , each Cd(II) ion is six‐coordinate bonded to six nitrogen atoms from four 3‐bpd and two NCS? ligands. The 3‐bpd acts as a bridging ligand connecting the Cd(II) ion to generate a 2D layered metal‐organic framework (MOF) by using a rhomboidal‐grid as the basic building units with the 44 topology. In compound 2 , the Cd(II) ion is also six‐coordinate bonded to four nitrogen atoms of two 3‐bpd, two dpe and two oxygen atoms of two NO3? ligands. The 3‐bpd and dpe ligands both adopt bis‐monodentate coordination mode connecting the Cd(II) ions to generate a 2D layered MOF by using a rectangle‐grid as the basic building units with the 44 topology. In compound 3 , two crystallographically independent Cd(II) ions are both coordinated by four nitrogen atoms of dpe ligands in the basal plane and two nitrogen atom of NCS? in the axial sites. The dpe acts as a bridging ligand to connect the Cd(II) ions forming a 2D interpenetrating MOFs by using a square‐grid as the basic unit with the 44 topology. All of their 2D layered MOFs in compounds 1 ‐ 3 are then arranged in a parallel non‐interpenetrating ABAB—packing manner in 1 and 2 , and mutually interpenetrating manner in 3 , respectively, to extend their 3D supramolecular architectures with their 1D pores intercalated with solvent (ethanol in 1 or H2O in 3 ) or free 3‐bpd molecules in 2 and 3 , respectively. The photoluminescence measurements of 1 ‐ 3 reveal that the emission is tentatively assigned to originate from π‐π* transition for 1 and 2 and probably due to ligand‐center luminescence for compounds 3 , respectively. 相似文献
19.
Synthesis of 3‐(ω‐Hydroxyalkoxy)isobenzofuran‐1(3H)‐ones by Trifluoroacetic Acid‐Mediated Lactonization of tert‐Butyl 2‐(1,3‐Dioxol‐2‐yl)‐ or 2‐(1,3‐Dioxan‐2‐yl)benzoates 下载免费PDF全文
An efficient two‐step method for the preparation of 3‐(2‐hydroxyethoxy)‐ or 3‐(3‐hydroxypropoxy)isobenzofuran‐1(3H)‐ones 3 has been developed. Thus, the reaction of 1‐(1,3‐dioxol‐2‐yl)‐ or 1‐(1,3‐dioxan‐2‐yl)‐2‐lithiobenzenes, generated in situ by the treatment of 1‐bromo‐2‐(1,3‐dioxol‐2‐yl)‐ or 1‐bromo‐2‐(1,3‐dioxan‐2‐yl)benzenes 1 with BuLi in THF at ?78°, with (Boc)2O afforded tert‐butyl 2‐(1,3‐dioxol‐2‐yl)‐ or 2‐(1,3‐dioxan‐2‐yl)benzoates 2 , which can subsequently undergo facile lactonization on treatment with CF3COOH (TFA) in CH2Cl2 at 0° to give the desired products in reasonable yields. 相似文献
20.
Alexander V. Martynov Vladimir A. Shagun Svetlana V. Amosova 《Heteroatom Chemistry》2016,27(5):253-259
Oxidation of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfide and selenide with hydrogen peroxide in chloroform/acetic acid or acetic acid affords previously unknown E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfoxide, selenoxide, and sulfone. The reaction of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfone with primary amines in ethanol in the presence of NaHCO3 or Na2CO3 is found to lead not only to heterocyclization but also to alcoholysis of the chloromethylidene groups in the intermediate bis(chloromethylidene) derivatives of thiomorpholine‐1,1‐dioxides to afford N‐organyl‐2(E),6(E)‐bis(ethoxymethylidene) thiomorpholine‐1,1‐dioxides as final products. 相似文献