共查询到20条相似文献,搜索用时 15 毫秒
1.
Maria Eleni Ourailidou Jan‐Ytzen van der Meer Bert‐Jan Baas Margot Jeronimus‐Stratingh Dr. Aditya L. Gottumukkala Prof. Dr. Gerrit J. Poelarends Prof. Dr. Adriaan J. Minnaard Prof. Dr. Frank J. Dekker 《Chembiochem : a European journal of chemical biology》2014,15(2):209-212
An increasing number of chemical reactions are being employed for bio‐orthogonal ligation of detection labels to protein‐bound functional groups. Several of these strategies, however, are limited in their application to pure proteins and are ineffective in complex biological samples such as cell lysates. Here we present the palladium‐catalyzed oxidative Heck reaction as a new and robust bio‐orthogonal strategy for linking functionalized arylboronic acids to protein‐bound alkenes in high yields and with excellent chemoselectivity even in the presence of complex protein mixtures from living cells. Advantageously, this reaction proceeds under aerobic conditions, whereas most other metal‐catalyzed reactions require inert atmosphere. 相似文献
2.
Daniel G. Bachmann Christopher C. Wittwer Dennis G. Gillingham 《Advanced Synthesis \u0026amp; Catalysis》2013,355(18):3703-3707
We report the Heck cross‐coupling of notoriously unreactive, but synthetically valuable olefins: vinyl sulfoxides, vinyl sulfones, and vinyl sulfides. Key findings include the importance of the sterically hindered (tri‐tert‐butyl)phosphine ligand and the unique effectiveness of triethylamine as the base. The method is general, E‐selective, and can be used to synthesize disubstituted or trisubstituted olefins through simple adjustments of stoichiometry.
3.
Anita Schnyder Thomas Aemmer AdrianoF. Indolese Ulrich Pittelkow Martin Studer 《Advanced Synthesis \u0026amp; Catalysis》2002,344(5):495-498
Secondary dialkylphosphines were successfully used for the first time as efficient supporting ligands for the palladium‐catalyzed Heck reaction of electron‐rich and electron‐poor aryl chlorides with olefins such as acrylate, ethylene, styrene, and n‐butyl vinyl ether. The yields with HP(t‐butyl)2 and HP(adamantyl)2 were comparable or better than those obtained with known systems of tertiary phosphines such as P(cyclohexyl)3 and P(t‐butyl)3, especially at a catalyst loading of <1 mol %. In comparison with tertiary phosphines, the secondary phosphines have the advantage of being readily available at low cost on a technical scale, and are comparable with respect to handling and oxygen sensitivity. 相似文献
4.
M. Paz Muoz Beln Martín‐Matute Carolina Fernndez‐Rivas Diego J. Crdenas Antonio M. Echavarren 《Advanced Synthesis \u0026amp; Catalysis》2001,343(4):338-342
A variety of palladacycles are shown to catalyze Heck alkenylations with similar efficiencies. The new oxapalladacycle 1 was shown to insert and transmetalate under mild conditions with n‐butyl acrylate and vinyltributylstannane, respectively. This palladacycle acts as an active (pre)catalyst for cross‐coupling and Heck reactions. 相似文献
5.
Rosana lvarez Olalla Nieto Faza AngelR. de Lera DiegoJ. Crdenas 《Advanced Synthesis \u0026amp; Catalysis》2007,349(6):887-906
An associative mechanism has been computationally characterized for the Stille cross‐coupling of vinyl bromide and trimethylvinylstannane catalyzed by PdL2 (L=PMe3, AsMe3) with or without dimethylformamide as coordinating ligand. All the species along the catalytic cycles that start from both the cis‐ and the trans‐PdL(Y)(vinyl)Br complexes (Y=L or S; L=PMe3, AsMe3 or PH3; S=DMF) have been located in the gas phase and in the presence of polar solvents. Computations support the central role of species trans‐PdL(DMF)(vinyl)Br which react by ligand dissociation and stannane coordination in the rate‐limiting transmetalation step via a puckered four‐coordinate (at palladium) transition state comprised of Pd, Br, Sn and sp2 C atoms. A donating solvent may enter the catalytic cycle assisting isomerization of cis‐PdL2(vinyl)Br to trans‐PdL(DMF)(vinyl)Br complexes via a pentacoordinate square pyramidal Pd intermediate. In keeping with experimental observations, the activation energies of the catalytic cycles with arsines as Pd ligands are lower than those with phosphines. Polytopal rearrangements from the three‐coordinate T‐shaped Pd complexes resulting from transmetalation account for the isomerization and the C C bond formation on the reductive elimination step. 相似文献
6.
DiegoA. Alonso Carmen Njera MaCarmen Pacheco 《Advanced Synthesis \u0026amp; Catalysis》2002,344(2):172-183
Oxime‐derived, chloro‐bridged palladacycles 16 are efficient complexes for the Heck vinylation of aryl halides. The isolated catalysts are thermally stable, not sensitive to air or moisture and easily accessible from inexpensive starting materials. The reaction can be performed under aerobic conditions, with aryl iodides, bromides and chlorides with acrylic esters and olefins displaying turnover numbers (TON) of up to 1010 for phenyl iodide and turnover frequencies (TOF) of 1.4×108 h−1. Deactivated aryl bromides undergo the Heck reaction with styrene with TON and TOF values up to 97,000 and 6063 h−1, respectively. Even aryl chlorides undergo the coupling reaction with olefins with TON up to 920. Complexes 16 catalyze the synthesis of 2,3‐disubstituted indenones and indoles in good yields via annulation reaction of internal alkynes with o‐bromo‐ or o‐chlorobenzaldehyde and o‐iodoaniline, respectively. 相似文献
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M. LakshmiKantam Sarabindu Roy Moumita Roy B. Sreedhar B.M. Choudary 《Advanced Synthesis \u0026amp; Catalysis》2005,347(15):2002-2008
A nanocrystalline magnesium oxide‐stabilized palladium(0) catalyst is prepared by counterion stabilization of PdCl42− with nanocrystalline MgO followed by reduction. This ligand‐free heterogeneous nanocrystalline MgO‐stabilized nanopalladium [NAP Mg Pd(0)] catalyst using the basic MgO in place of basic ligands exhibits excellent activity in Suzuki and Stille cross‐coupling of haloarenes (chloro, bromo and iodo) to afford the unsymmetrical biaryls. The catalyst is quantitatively recovered by simple filtration and reused for four cycles with almost consistent activity. 相似文献
9.
Pinhua Li Lei Wang Lei Zhang Guan‐Wu Wang 《Advanced Synthesis \u0026amp; Catalysis》2012,354(7):1307-1318
A highly efficient, air‐ and moisture‐stable and easily recoverable magnetic nanoparticle‐supported palladium catalyst has been developed for the Suzuki, Sonogashira and Heck reactions. A wide range of substrates was coupled successfully under aerobic conditions. In particular, the performance of the magnetic separation of the catalyst was very efficient, and it is possible to recover and reuse it at least eight times without significant loss of its catalytic activity. 相似文献
10.
Giovanni Imperato Rudolf Vasold Burkhard Knig 《Advanced Synthesis \u0026amp; Catalysis》2006,348(15):2243-2247
The transfer of simple alkyl groups in Stille reactions usually requires special solvents (HMPA) or certain organotin reagents (stannatranes, monoorganotin halides) to be efficient. Using low‐melting mixtures of sugar, urea and inorganic salt as solvent, a fast and efficient palladium‐catalyzed alkyl transfer with tetraalkyltin reagents was observed. The high polarity and nucleophilic character of the solvent melt promotes the reaction. Stille biaryl synthesis using electron‐poor and electron‐rich aryl bromides proceeds with quantitative yields in the sugar‐urea‐salt melt. Catalyst loading may be reduced to 0.001 mol % and the catalyst melt mixture remains active in several reaction cycles. Showing the same or improved performance for Stille reactions than organic solvents and allowing a very simple work up, sugar‐urea‐salt melts are a non‐toxic and cheap alternative reaction medium available in bulk quantities for the catalytic process. 相似文献
11.
Franois‐Xavier Felpin Eric Fouquet Ccile Zakri 《Advanced Synthesis \u0026amp; Catalysis》2008,350(16):2559-2565
A property‐activity relationship study of various palladium supported on charcoal (Pd/C) catalysts has been undertaken for the Heck reaction of aryldiazonium tetrafluoroborate with acrylates. The optimized protocol enables the cross‐coupling with a low loading of palladium at room temperature in technical grade methanol. Although the catalyst could not be recycled at this time, measurement of the palladium content by inductively coupled plasma mass spectrometry (ICP‐MS) shows low palladium contamination of the solvent and product, rendering this method safer for the environment compared to homogeneous conditions. 相似文献
12.
S. Proch Y. Mei J.M. Rivera Villanueva Y. Lu A. Karpov M. Ballauff R. Kempe 《Advanced Synthesis \u0026amp; Catalysis》2008,350(3):493-500
We report on a systematic study of the use of palladium nanoparticles immobilized on spherical polyelectrolyte brushes – Pd@SPB – for Heck‐ and Suzuki‐type coupling reactions. The spherical polyelectrolyte brush particles serving as carriers for the palladium nanoparticles consist of a solid polystyrene core with a radius of 46 nm onto which long chains of cationic polyelectrolytes are grafted. The palladium nanoparticles have directly been generated within this brush layer and the stabilization of the nanoparticles is effected by the colloidal carriers, no further surface stabilization is necessary. We demonstrate that these composite particles present robust catalysts for the Heck‐ and Suzuki‐type coupling reactions. This was shown by carrying out the Suzuki‐ and Heck‐type coupling reactions at relatively low temperatures (Suzuki reaction: 50 °C, Heck reaction: 70 °C). We demonstrate that the catalytic composite particles are not changed by these reaction conditions and retain their full activity for at least four runs. The yields obtained for both reactions are good to excellent. The mild operation conditions of the palladium nanoparticles are traced back to the absence of surface stabilization. Further mechanistic implications are discussed. 相似文献
13.
Shang Gao Zijun Wu Fei Wu Aijun Lin Hequan Yao 《Advanced Synthesis \u0026amp; Catalysis》2016,358(24):4129-4135
A catalyst‐controlled regiodivergent dehydrogenative Heck reaction of 4‐arylthiophene/furan‐3‐carboxylates has been realized. Use of a palladium catalyst led to the C‐5 alkenylation through electronic palladation, while a ruthenium catalyst favored the C‐2 alkenylation with the assistance of a directing group. This reaction exhibited good to excellent regioselectivities.
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Fenglin Hong Yingwen Chen Beili Lu Jiajia Cheng 《Advanced Synthesis \u0026amp; Catalysis》2016,358(3):353-357
A one‐pot, two‐step cyclization reaction of iodoarenes with diversified arylols, including 4‐hydroxyquinoline, quinolinone, 4‐hydroxypyridine and phenol, has been developed. By using this palladium‐catalyzed formal tandem O‐arylation, dehydrogenative cross‐coupling reaction, a variety of biologically significant fused benzo[4,5]furo heterocycles and dibenzofurans were quickly assembled in high yields with excellent regioselectivity. Notably, the efficient one‐pot reaction led to the heterocycles via sequential oxidation, iodination, isomerization and cyclization steps without purification of any reaction intermediates.
16.
Satoshi Haneda Chigusa Ueba Kazuo Eda Masahiko Hayashi 《Advanced Synthesis \u0026amp; Catalysis》2007,349(6):833-835
Imidazole and imidazoline (dihydroimidazole) derivatives can serve as efficient and simple ligands for the palladium‐catalyzed Mizoroki–Heck reaction. Among the imidazole and imidazoline derivatives in our investigations, the 2‐methylimidazoline‐palladium(II) chloride complex exhibited the highest catalytic activity. 相似文献
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Youngtaek Moon Soonhyung Kwon Dahye Kang Honggu Im Sungwoo Hong 《Advanced Synthesis \u0026amp; Catalysis》2016,358(6):958-964
We have developed a new strategy for palladium‐catalyzed arylation reactions with triazolopyridines, wherein two different chemical transformations (C‐3 vs. C‐7) are observed by differentiating the substrates using different bases. The reactive palladium carbenoids were directly generated from triazolopyridines and underwent denitrogenative arylations with aryl bromides. Intriguingly, when potassium carbonate was replaced with potassium tert‐butoxide, direct C H arylation occurred at the most acidic position (C‐7). Moreover, two different catalytic arylation events were successfully performed in a one‐pot sequence, providing a convenient access to 6‐aryl‐2‐α‐styrylpyridines.
19.
Paul Colbon Jonathan H. Barnard Mark Purdie Keith Mulholland Ivan Kozhevnikov Jianliang Xiao 《Advanced Synthesis \u0026amp; Catalysis》2012,354(8):1395-1400
Aryl alcohols are employed as feedstock for the Heck reaction. Keggin‐type heteropolyacids catalyse the selective dehydration of the alcohols to styrenes, which, in one‐pot, undergo palladium‐catalysed Heck arylation with aryl bromides, affording broadly functionalised stilbenes. The choice of solvent is critical for the cascade dehydration–Heck reaction, with electron‐rich aryl alcohols preferring a basic medium while electron‐deficient ones demanding solvents of lower basicity. 相似文献
20.
Amir Landarani Isfahani Iraj Mohammadpoor‐Baltork Valiollah Mirkhani Ahmad R. Khosropour Majid Moghadam Shahram Tangestaninejad Reza Kia 《Advanced Synthesis \u0026amp; Catalysis》2013,355(5):957-972
A new catalyst based on palladium nanoparticles immobilized on nano‐silica triazine dendritic polymer (Pdnp‐nSTDP) was synthesized and characterized by FT‐IR spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, energy dispersive X‐ray, transmission electron microscopy and elemental analysis. The size of the palladium nanoparticles was determined to be 3.1±0.5 nm. This catalytic system showed high activity in the Suzuki–Miyaura cross‐coupling of aryl iodides, bromides and chlorides with arylboronic acids and also in the Heck reaction of these aryl halides with styrenes. These reactions were best performed in a dimethylformamide (DMF)/water mixture (1:3) in the presence of only 0.006 mol% and 0.01 mol% of the catalyst, respectively, under conventional conditions and microwave irradiation to afford the desired coupling products in high yields. The Pdnp‐nSTDP was also used as an efficient catalyst for the preparation of a series of star‐ and banana‐shaped compounds with a benzene, pyridine, pyrimidine or 1,3,5‐triazine unit as the central core. Moreover, the catalyst could be recovered easily and reused several times without any considerable loss of its catalytic activity. 相似文献