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1.
Enantioselective Palladium‐Catalyzed Insertion of α‐Aryl‐α‐diazoacetates into the OH Bonds of Phenols
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Xiu‐Lan Xie Prof. Shou‐Fei Zhu Jun‐Xia Guo Yan Cai Prof. Qi‐Lin Zhou 《Angewandte Chemie (International ed. in English)》2014,53(11):2978-2981
A palladium‐catalyzed asymmetric O? H insertion reaction was developed. Palladium complexes with chiral spiro bisoxazoline ligands promoted the insertion of α‐aryl‐α‐diazoacetates into the O? H bond of phenols with high yield and excellent enantioselectivity under mild reaction conditions. This palladium‐catalyzed asymmetric O? H insertion reaction provided an efficient and highly enantioselective method for the preparation of synthetically useful optically active α‐aryl‐α‐aryloxyacetates. 相似文献
2.
Dr. Anna Berlicka Paweł Dutka Dr. Ludmiła Szterenberg Prof. Lechosław Latos‐Grażyński 《Angewandte Chemie (International ed. in English)》2014,53(19):4885-4889
In the search for porphyrinoids with a built‐in cyclopentadienyl moiety (true carbaporphyrins), a rational synthesis of carbathiaporphyrin, the synthons, has been elaborated. The donors (C,N,S,N) in the porphyrinic core of carbathiaporphyrinoids are potentially of fundamental importance for generating organometallic complexes, as exemplified through formation of the palladium(II) complex. 相似文献
3.
A new method of preparing 2,2′‐bipyridines with short reaction times by using microwave assistance and heterogeneous catalysts has been developed. With a Negishi‐like protocol, it was found that Ni/Al2O3–SiO2 afforded 2,2′‐bipyridine products in up to 86 % yield in 1 h. Palladium supported on alumina also provided yields of 2,2′‐bipyridines comparable to those seen for homogeneous PEPPSITM (1,3‐diisopropylimidazol‐2‐ylidene)(3‐chloropyridyl)palladium(II)dichloride) and tetrakis(triphenylphosphanyl)palladium complexes. 相似文献
4.
Partially fluorinated 1,4‐Diazadiene (α‐Diimine) ligand 3,5‐CF3‐BIAN (1) formed from 3,5‐bis(trifluoromethyl)aniline and acenaphthenequinone was used in the synthesis of palladium dichlorido complex 2 and its mono methyl chlorido palladium complex 3 . Both complexes as well as side products of the reaction with methyl lithium such as trans‐bis(3,5‐bis(trifluoromethyl)aniline complex 4 and an interesting mixed valent trinuclear V‐shaped palladium cluster 5 with two bridging μ2,η3‐N,CN′ non‐innocent BIAN ligands were structurally characterized by the single‐crystal XRD method. 相似文献
5.
Rafet Kılınçarslan M. Emin Günay Rukiye Fırıncı Serpil Denizaltı Bekir Çetinkaya 《应用有机金属化学》2016,30(5):268-272
A new series of sterically hindered ligands containing (1R,2S,4R)‐(+)‐menthoxymethyl group attached to benzimidazole‐based N‐heterocyclic carbene (NHC), palladium–bis‐NHC complexes and (κ2‐C,N)‐palladacyclic NHC complexes have been synthesized and characterized using appropriate spectroscopic techniques. Catalytic performance of the palladium complexes has been investigated for allylic alkylation, Suzuki and Heck carbon–carbon coupling reactions. These complexes smoothly catalyse the carbon–carbon bond formation reactions. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
6.
Synthesis,Characterization, and Theoretical Investigation of Two‐Coordinate Palladium(0) and Platinum(0) Complexes Utilizing π‐Accepting Carbenes
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Dr. Sudipta Roy Dr. Kartik Chandra Mondal Dipl.‐Chem. Jann Meyer Dipl.‐Chem. Benedikt Niepötter Christian Köhler Dr. Regine Herbst‐Irmer Prof. Dr. Dietmar Stalke Dr. Birger Dittrich Dr. Diego M. Andrada Prof. Dr. Gernot Frenking Prof. Dr. Herbert W. Roesky 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(26):9312-9318
An elegant general synthesis route for the preparation of two coordinate palladium(0) and platinum(0) complexes was developed by reacting commercially available tetrakis(triphenylphosphine)palladium/platinum with π‐accepting cyclic alkyl(amino) carbenes (cAACs). The complexes are characterized by NMR spectroscopy, mass spectrometry, and single‐crystal X‐ray diffraction. The palladium complexes exhibit sharp color changes (crystallochromism) from dark maroon to bright green if the C‐Pd‐C bond angle is sharpened by approximately 6°, which is chemically feasible by elimination of one lattice THF solvent molecule. The analogous dark orange‐colored platinum complexes are more rigid and thus do not show this phenomenon. Additionally, [(cAAC)2Pd/Pt] complexes can be quasi‐reversibly oxidized to their corresponding [(cAAC)2Pd/Pt]+ cations, as evidenced by cyclic voltammetry measurements. The bonding and stability are studied by theoretical calculations. 相似文献
7.
One‐Handed Single Helicates of Dinickel(II) Benzenehexapyrrole‐α,ω‐diimine with an Amine Chiral Source
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Dr. Chaolu Eerdun Satoshi Hisanaga Prof. Dr. Jun‐ichiro Setsune 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):239-246
Benzenehexapyrrole‐α,ω‐dialdehyde, composed of a pair of formyltripyrrole units with a 1,3‐phenylene linker, was metallated to give dinuclear single‐stranded helicates. X‐ray studies of the bis‐nickel(II) complex showed a helical C2 form with a pair of helical–metal coordination planes of a 3N+O donor set. The terminal aldehyde was readily converted into the imine by optically active amines, whereby helix‐sense bias was induced. Bis‐nickel(II) and bis‐palladium(II) complexes of the benzenehexapyrrole‐α,ω‐diimines were studied to show that an enantiomer pair of the helical C2 form are interchanged by slow flipping of each coordination plane and fast rotation around the C(benzene)?C(pyrrole) bond. The helical screw in the bis‐nickel(II) complexes was biased to one side in more than 95 % diastereoselectivity, which was achieved by using a variety of optically active amines, such as (R)‐1‐cyclohexylethylamine, (S)‐1‐ phenylethylamine, L ‐Phe(OEt) (Phe=phenylalanine), and (R)‐valinol. The nickel complexes showed much better diastereoselectivity than the corresponding palladium complexes. 相似文献
8.
Ping Huo Wanyun Liu Xiaohui He Yiwang Chen 《Journal of polymer science. Part A, Polymer chemistry》2014,52(22):3213-3220
The covalently immobilized multiwalled carbon nanotubes (MWNTs) supported three‐dimensional geometry α‐diimine nickel, palladium catalysts are prepared by corresponding α‐diimine nickel, palladium complexes and activated MWNTs. The molecular structures of the catalysts have been confirmed by X‐ray single‐crystal analyses, NMR and XPS, as well as elemental analysis. Compared with nickel, palladium catalysts without modification and physical mixing of nickel, palladium catalysts with MWNTs, the MWNTs supported nickel, palladium catalysts show improved activity and productivity in norbornene homopolymerization and copolymerization with polar monomer. The morphology of the resulting polymers obtained from MWNTs‐supported nickel(II) complex reveals that the MWNTs are dispersed uniformly in polymer and wrapped by polymers to squeeze out of spherical particles, leading to the enhanced processability and mechanical properties. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3213–3220 相似文献
9.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(35):10705-10708
By using mechanistic insight, a new ligand (EPhos) for the palladium‐catalyzed C−N cross‐coupling between primary amines and aryl halides has been developed. Employing an isopropoxy group at the C3‐position favors the C‐bound isomer of the ligand‐supported palladium(II) complexes and leads to significantly improved reactivity. The use of a catalyst system based on EPhos with NaOPh as a mild homogeneous base proved to be very effective in the formation of 4‐arylaminothiazoles and highly functionalized 2‐arylaminooxazoles. Previously, these were not readily accessible using palladium catalysis. 相似文献
10.
J. Gonzalo Rodríguez Jose Luis Tejedor 《Journal of polymer science. Part A, Polymer chemistry》2007,45(10):2038-2047
The monomer 5‐[(5‐ethynyl‐1‐naphthyl)ethynyl]‐N,N‐dimethylnaphthalen‐1‐amine was satisfactory obtained through the heterocoupling reaction of 5‐ethynyl‐N,N‐dimethylnaphthalen‐1‐amine and 4‐(5‐iodo‐1‐naphthyl)‐2‐methyl‐3‐butyn‐2‐ol catalyzed by a palladium–copper system, followed by acetone elimination. Poly{5‐[(5‐ethynyl‐1‐naphthyl)ethynyl]‐N,N‐dimethylnaphthalen‐1‐amine} was obtained through the reaction of the acetylene monomer with homogeneous rhodium and palladium catalyst complexes. The structure of the polymers always showed a trans–cisoidal chain configuration on the basis of IR and NMR spectra. Moreover, only for the rhodium catalyst complex in methanol was a dimeric product isolated in a very low yield, having a conjugated terminal ene–yne structure, which permitted the consideration of a metallated chain‐transfer intermediate in the polymer propagation. The mass determination of the polymers, by osmometry and gel permeation chromatography techniques, showed low average molecular weights. The kinetics of the catalyzed polymerization were analyzed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2038–2047, 2007 相似文献
11.
Imidazolin‐2‐ylidenaminophosphines as Highly Electron‐Rich Ligands for Transition‐Metal Catalysts
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Marius A. Wünsche Paul Mehlmann Tim Witteler Florenz Buß Patrick Rathmann Dr. Fabian Dielmann 《Angewandte Chemie (International ed. in English)》2015,54(40):11857-11860
A variety of chemical transformations benefit from the use of strong electron‐donating ancillary ligands, such as alkylphosphines or N‐heterocyclic carbenes when electron‐rich metal centers are required. Herein, we describe a facile and highly modular access to monodentate and bidentate imidazolin‐2‐ylidenamino‐substituted phosphines. Evaluation of the phosphine’s electronic properties substantiate that the formal replacement of alkyl or aryl groups by imidazolin‐2‐ylidenamino groups dramatically enhance their donor ability beyond that of alkylphosphines and even N‐heterocyclic carbenes. The new phosphines have been coordinated onto palladium(II) centers, and the beneficial effect of the novel substitution patterns has been explored by using the corresponding complexes in the palladium‐catalyzed Suzuki–Miyaura cross‐coupling reaction of non‐activated aryl chloride substrates. 相似文献
12.
5‐Methylene‐2‐oxazolidinone (1) and 5‐methylene‐1,3‐thiazolidine‐2‐thione (4) react with various isocyanates to give the corresponding urethanes 3 and 5 in high yields in the presence of palladium(0) or palladium(II) catalyst under mild reaction conditions. A mechanism is proposed. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
13.
Silica obtained by acid treatment of sepiolite was used as a support for catalysts consisting of palladium complexes of 2‐ and 3‐thiophenecarbaldehyde. The support and the catalysts were characterized by X‐ray diffraction, and solid‐state 29Si and 13C nuclear magnetic resonance spectroscopies. The supported palladium catalysts were used in the Suzuki reaction of bromobenzene with phenylboronic acid. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
14.
《应用有机金属化学》2017,31(5)
New palladium(II) complexes, [Pd(PPh3)L] ( 2 ) and [Pd(AsPh3)L] ( 3 ), were synthesized using 4‐hydroxybenzoic acid (3‐ethoxy‐2‐hydroxybenzylidene)hydrazide ( 1 ) ligand (H2L), and characterized using various physicochemical techniques. The molecular structures of 2 and 3 were determined using single‐crystal X‐ray diffraction, which reveals a square planar geometry around the palladium(II) metal ion. In vitro DNA binding studies were conducted using UV–visible absorption spectroscopy, emission spectroscopy, cyclic voltammetry and viscosity measurements, which suggest that the metal complexes act as efficient DNA binders. The interaction of ligand H2L and complexes 2 and 3 with bovine serum albumin (BSA) was investigated using UV–visible and fluorescence spectroscopies. Absorption and emission spectral studies indicate that complexes 2 and 3 interact with BSA protein more strongly than the parent ligand. The free radical scavenging potential of all the synthesised compounds ( 1 – 3 ) was also investigated under in vitro conditions. In addition, the in vitro cytotoxicity of the complexes to tumour cells lines (HeLa and MCF‐7) was examined using the MTT assay method. 相似文献
15.
Seema Yadav Ajeet Singh Isha Mishra Sriparna Ray Shaikh M. Mobin Chandrakanta Dash 《应用有机金属化学》2019,33(7)
Well‐defined and air‐stable PEPPSI (Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation) themed palladium bis‐N‐heterocyclic carbene complexes have been developed for the domino Sonogashira coupling/cyclization reaction of 2‐iodophenol with a variety of terminal alkynes and C‐H bond arylation of benzothiazole with aryl iodides. The PEPPSI themed palladium complexes, 2a and 2b were synthesized in good yields from the reaction of corresponding imidazolium salts with PdCl2 and K2CO3 in pyridine. The new air‐stable palladium‐NHC complexes were characterized by NMR spectroscopy, X‐ray crystallography, elemental analysis, and mass spectroscopy studies. The PEPPSI themed palladium(II) bis‐N‐heterocyclic carbene complexes 2a and 2b exhibited excellent catalytic activities for domino Sonogashira coupling/cyclization reaction of 2‐iodophenol with terminal alkynes yielding benzofuran derivatives. In addition, the palladium complexes, 2a and 2b successfully catalyzed the direct C‐H bond arylation of benzothiazole with aryl iodides as coupling partners in presence of CuI as co‐catalyst. 相似文献
16.
In the presence of CuCl2, N‐(2′, 4′‐dienyl)‐2‐alkynamides can be converted to α‐alkylidene‐σ‐butyrolactams under the catalysis of palladium(II). In this reaction, CuCl2 is used to oxidize Pd(0) to regenerate Pd(II), or the carbon‐palladium bond is quenched by the oxidative cleavage reaction of CuCl2. 相似文献
17.
Palladium(II)‐N‐Heterocyclic Carbene Complexes: Efficient Catalysts for the Direct C‐H Bond Arylation of Furans with Aryl Halides
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This paper contains the synthesis and characterization of the seven new benzimidazolium salts and their corresponding new palladium(II)‐NHC complexes with the general formula [PdX2(NHC)2], (NHC = N‐heterocyclic carbene, X = Cl or Br), and also their catalytic activity in direct C‐H bond arylation of 2‐substituted furan derivatives with aryl bromides and aryl chlorides. Under the optimal conditions, these palladium(II)‐NHC complexes showed the good catalytic performance for the direct C‐H bond arylation of 2‐substituted furans with (hetero)aryl bromides, and with readily available and inexpensive aryl chlorides. The C‐H bond arylation regioselectively produced C5‐arylated furans by using 1 mol% of the palladium(II)‐NHC catalysts in moderate to high yields. 相似文献
18.
Investigation of the Catalytic Activity of a 2‐Phenylidenepyridine Palladium(II) Complex Bearing 4,5‐Dicyano‐1,3‐bis(mesityl)imidazol‐2‐ylidene in the Mizoroki‐Heck Reaction
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The phenylidenepyridine (ppy) palladacycles [PdCl(ppy)(IMes)] ( 4 ) [IMes = 1,3‐bis(mesityl)imidazol‐2‐ylidene] and [PdCl(ppy){(CN)2IMes}] ( 6 ) [(CN)2IMes = 4,5‐dicyano‐1,3‐bis(mesityl)imidazol‐2‐ylidene] were prepared by facile two step syntheses, starting with the reaction of palladium(II) chloride with 2‐phenylpyridine followed by subsequent addition of the NHC ligand to the precatalyst precursor [PdCl(ppy)]2. Suitable crystals for the X‐ray analysis of the complexes 4 and 6 were obtained. It was shown that 6 has a shorter NHC‐palladium bond than the IMes complex 4 . The difference of the palladium carbene bond lengths based on the higher π‐acceptor strength of (CN)2IMes in comparison to IMes. Thus, (CN)2IMes should stabilize the catalytically active central palladium atom better than IMes. As a measure for the π‐acceptor strength of (CN)2IMes compared to IMes, the selone (CN)2IMes · Se ( 7 ) was prepared and characterized by 77Se‐NMR spectroscopy. The π‐acceptor strength of 7 was illuminated by the shift of its 77Se‐NMR signal. The 77Se‐NMR signal of 7 was shifted to much higher frequencies than the 77Se‐NMR signal of IMes · Se. Catalytic experiments using the Mizoroki‐Heck reaction of aryl chlorides with n‐butyl acrylate showed that 6 is the superior performer in comparison to 4 . Using complex 6 , an extensive substrate screening of 26 different aryl bromides with n‐butyl acrylate was performed. Complex 6 is a suitable precatalyst for para‐substituted aryl bromides. The catalytically active species was identified by mercury poisoning experiments to be palladium nanoparticles. 相似文献
19.
CH–π and CF–π Interactions Lead to Structural Changes of N‐Heterocyclic Carbene Palladium Complexes
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Xiangya Xu Benjamin Pooi Prof. Dr. Hajime Hirao Prof. Dr. Soon Hyeok Hong 《Angewandte Chemie (International ed. in English)》2014,53(5):1283-1287
The role of CH–π and CF–π interactions in determining the structure of N‐heterocyclic carbene (NHC) palladium complexes were studied using 1H NMR spectroscopy, X‐ray crystallography, and DFT calculations. The CH–π interactions led to the formation of the cis‐anti isomers in 1‐aryl‐3‐isopropylimidazol‐2‐ylidene‐based [(NHC)2PdX2] complexes, while CF–π interactions led to the exclusive formation of the cis‐syn isomer of diiodobis(3‐isopropyl‐1‐pentafluorophenylimidazol‐2‐ylidene) palladium(II). 相似文献
20.
Wen‐Jie Tao Dr. Jun‐Fang Li Ai‐Qing Peng Dr. Xiu‐Li Sun Xiao‐Hong Yang Prof. Dr. Yong Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(41):13956-13961
By a reasonable combination of the Wacker reaction and olefin polymerization processes, water proves to be an excellent activator for the palladium(II)‐catalyzed polymerization of ethylene and it provides a safe, environmental‐friendly and handy initiator for olefin polymerization. The activity of the olefin polymerization is comparable to reactions catalyzed by the corresponding alkylated cationic palladium complexes. 相似文献