- Newly-generated Al(OH)3-supported Pd nanoparticles-catalyzed Stille and Kumada coupling reactions of diazonium salts, (Het)aryl chlorides
-
A ligand-free Pd/Al(OH)3 nano-catalyst which is prepared by one-pot three-component method using Pd(PPh3)4, tetra (ethylene glycol), and aluminum tri-sec-butoxide exhibits excellent catalytic activity in Stille cross-couplings of (Het)aryl chlorides, arenediazonium tetrafluoroborate salts with phenyltributylstannane, respectively, and Kumada couplings of (Het)aryl chlorides with various Grignard reagents. More importantly, these two processes show excellent functional group compatibility with moderate to good yields and they are also versatile with respect to not only (Het)aryl chlorides, but also diazonium salts, and heteroaryl Grignard reagents. The nano-catalyst could also be recycled and reused 5 times without loss of activity and decrease of yield.
- Li, Xing,Zhu, Tingting,Shao, Zhongqi,Li, Yingjun,Chang, Honghong,Gao, Wenchao,Zhang, Yongli,Wei, Wenlong
-
-
Read Online
- Nickel catalyzed cross-coupling and amination reactions of aryl nitriles
-
Aryl nitriles have been found to participate in cross-coupling and amination reactions via nickel-catalyzed activation of the C-CN bond. With the development of these synthetically useful transformations, aryl nitriles can now be considered along with ary
- Miller, Joseph A.,Dankwardt, John W.,Penney, Jonathan M.
-
-
Read Online
- Pd(OAc)2-catalyzed fluoride-free cross-coupling reactions of arylsiloxanes with aryl bromides in aqueous medium
-
(Chemical Equation Presented) Mild conditions have been developed to achieve the Pd-(OAc)2-catalyzed fluoride-free cross-coupling between the aryl bromides and arylsiloxanes in good to high yields in aqueous medium. The success of the reactions requires the presence of poly(ethylene glycol) (PEG) and 3 equiv of sodium hydroxide. The product was easily separated with ethyl ether extraction, and the catalytic system can be reused eight times with high efficiency.
- Shi, Shengyin,Zhang, Yuhong
-
-
Read Online
- Three Different Reactions, One Catalyst: A Cu(I) PNP Pincer Complex as Catalyst for C-C and C-N Cross-Couplings
-
An air-stable, thermally robust, and well-defined Cu(I) PNP pincer complex based on the 2,6-diaminopyridine scaffold is described. This complex is an active catalyst for the cross-couplings of a range of aryl and heteroaryl (including benzoxazole, thiazole, pyridine, and thiophene) halides with different organomagnesium reagents, alkynes, and aryl-amines giving excellent to good isolated yields.
- Mastalir, Matthias,Pittenauer, Ernst,St?ger, Berthold,Allmaier, Günter,Kirchner, Karl
-
-
Read Online
- N-heterocyclic carbene-Pd(II) complex based on theophylline supported on Fe3O4@SiO2 nanoparticles: Highly active, durable and magnetically separable catalyst for green Suzuki-Miyaura and Sonogashira-Hagihara coupling reactions
-
In this paper, a novel heterogeneous palladium catalyst was synthesized by anchoring N-heterocyclic carbene-Pd(II) complex based on theophylline on magnetic Fe3O4@SiO2 nanoparticles. The synthesized magnetic composite was characterized by fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), vibration sample magnetometry (VSM), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), N2 adsorption-desorption isotherm analysis (BET), UV–vis spectroscopy and elemental analysis. Also, loading content of palladium on the catalyst was measured by inductive coupled plasma (ICP) analysis. The synthesized catalyst was used successfully for the Suzuki cross-coupling reactions of various aryl halides (I, Br, Cl) with phenylboronic acids. This reaction was best performed in water as a green solvent in the presence of just 0.37–0.5 mol% of the catalyst at 60 °C. Also, we have reported this recyclable catalytic system as a stable phosphine-free Pd catalyst for the Sonogashira cross-coupling of aryl halides (I, Br, Cl) with terminal aromatic and aliphatic alkynes under solvent-free conditions. All coupling reactions proceeded with good to excellent yields. The catalyst showed good stability and was recovered and reused for eight reaction cycles without a significant loss in its catalytic activity. Also, the leaching of the catalyst has been examined by a hot filtration test and ICP-AES analysis.
- Esmaeilpour, Mohsen,Sardarian, Ali Reza,Firouzabadi, Habib
-
-
Read Online
- C-C coupling reactions of aryl bromides and arylsiloxanes in water catalyzed by palladium complexes of phosphanes modified with crown ethers
-
The complexes [PdCl2L2], where L is a crown-ether-containing triarylphosphane, catalyze the formation of biaryls from arylsiloxanes and aryl bromides with high yields In water as solvent and under air. The water-insoluble catalysts [PdCl2(PhCN)2] and [PdCl 2(PPh3)2] are also efficient, although they decompose more quickly to form black Pd0.
- Gordillo, Alvaro,De Jesus, Ernesto,Lopez-Mardomingo, Carmen
-
-
Read Online
- A pyridine-bridged bis-benzimidazolylidene pincer nickel(ii) complex: Synthesis and practical catalytic application towards Suzuki-Miyaura coupling with less-activated electrophiles
-
A novel robust pyridine-bridged bis-benzimidazolylidene nickel pincer complex 3 accessible from inexpensive, commercially available precursors efficiently catalyzes the first practical Suzuki-Miyaura cross-coupling reactions with various less-reactive electrophiles ArX (X = Br, Cl, OTs and OMs) and even tolerates electron-rich, sterically demanding and heterocyclic arenes in the presence of catalytic amounts of PPh3. The Royal Society of Chemistry.
- Tu, Tao,Mao, Han,Herbert, Christian,Xu, Mizhi,Doetz, Karl Heinz
-
-
Read Online
- A Polystyrene-Cross-Linking Tricyclohexylphosphine: Synthesis, Characterization and Applications to Pd-Catalyzed Cross-Coupling Reactions of Aryl Chlorides
-
A polystyrene-cross-linking tricyclohexylphosphine (PS-TCP) was synthesized through radical emulsion polymerization of 4-tert-butylstyrene as a monomer and tris(trans-4-styrylcyclohexyl)phosphine as a threefold cross-linker. The PS-TCP showed enhanced ligand performance compared to the corresponding polystyrene-triphenylphosphine hybrid PS-TPP and tricyclohexylphosphine in Pd-catalyzed Suzuki–Miyaura and Buchwald–Hartwig reactions of aryl chlorides.
- Arashima, Junya,Iwai, Tomohiro,Sawamura, Masaya
-
-
Read Online
- Leaving Group Ability in Nucleophilic Aromatic Amination by Sodium Hydride-Lithium Iodide Composite
-
The methoxy group is generally considered as a poor leaving group for nucleophilic substitution reactions. This work verified the superior ability of the methoxy group in nucleophilic amination of arenes mediated by the sodium hydride and lithium iodide through experimental and computational approaches.
- Chiba, Shunsuke,Ong, Derek Yiren,Pang, Jia Hao,Takita, Ryo,Watanabe, Kohei
-
-
Read Online
- Facile synthesis of highly active Pd-Cu nanowires catalyst through a simple wet-chemical strategy for ligand-free Suzuki cross coupling reaction
-
The construction and design of nanomaterials are important for improving their performance. Here we present a simple one-pot wet-chemical method for the preparation of alloyed Pd-Cu nanowires using octylphenoxypolyethoxyethanol (NP-40) as structure-directing and stabilizing agents. The obtained nanocrystals display outstanding catalytic activity for ligand-free Suzuki cross coupling reaction under mild conditions, and can be easily recovered and reused for at least 5 consecutive cycles without showing significant loss of catalytic activity.
- Lv, Jing-Jing,Wang, Zheng-Jun,Feng, Jiu-Ju,Qiu, Renhua,Wang, Ai-Jun,Xu, Xinhua
-
-
Read Online
- Transition-Metal-Free C-H Arylation of Unactivated Arenes with 8-Hydroxyquinoline as a Promoter
-
A method for the transition-metal-free direct C-H arylation of unactivated arenes is developed with aryl bromides as substrates and 8-hydroxyquinoline as an efficient promoter. A variety of biaryl compounds with structural diversity are obtained in moderate to high yields. Mechanistic studies reveal that the reaction proceeds via a homolytic aromatic substitution pathway.
- Zheng, Xuehua,Wu, Xu-Nian,Chen, Jing-Yi,Luo, Hai-Bin,Wu, Deyan,Wu, Yinuo
-
-
Read Online
- Complexes LNi(Cp)X with alkylamino-substituted N-heterocyclic carbene ligands (L) and their catalytic activity in the Suzuki—Miyaura reaction
-
New nickel(ii) complexes of the general formula LNi(Cp)X (L is an N-heterocyclic carbene (NHC) ligand of the 1,2,4-triazole or imidazole series; Cp is the cyclopentadienyl anion; X = Cl, I) are reported. In these complexes, the NHC ligands (L) contain an alkylamino group at the 3 or 4 position of the heterocycle. The synthesized complexes and structurally similar complexes without an alkylamino group were tested for catalytic activity in the Suzuki—Miyaura reaction. The introduction of an alkylamino group into the NHC ligand leads to the enhancement of the catalytic activity of complexes with N,N′-diaryl-substituted NHC ligands of the imidazole series and a decrease in the activity of the complexes with N,N′-dialkyl-substituted NHC ligands of the 1,2,4-triazole series.
- Chernyshev, V. M.,Chesnokov, V. V.,Shevchenko, M. A.,Soliev, S. B.,Tafeenko, V. A.
-
-
Read Online
- Naphthidine di(radical cation)s-stabilized palladium nanoparticles for efficient catalytic Suzuki-Miyaura cross-coupling reactions
-
Stable Pd(0) nanoparticles were prepared at room temperature in 1,4-dioxane from PdCl2 using N,N′-bis(4-methoxyphenyl)-(1,1′-binaphthyl)-4,4′-diamine (naphthidine) as reducing and stabilizing agent. This procedure resulted in Pd(0) particles possessing an average diameter of ca. 25 nm stabilized against aggregation due to a barrier of the naphthidine di(radical cation) Napht2.2+. These particles were evaluated for their capability to act as catalysts in Suzuki-Miyaura coupling reactions. The Pd(0)/Napht2.2+ provides a general and convenient method to prepare biaryls from aryl bromides or iodides and boronic acids with a broad range of functional groups in 1,4-dioxane at 80 °C and under aerobic conditions.
- Desmarets, Christophe,Omar-Amrani, Rafik,Walcarius, Alain,Lambert, Jacques,Champagne, Beno?t,Fort, Yves,Schneider, Rapha?l
-
-
Read Online
- Small organic molecules with tailored structures: Initiators in the transition-metal-free C-H arylation of unactivated arenes
-
Simple, small organic molecules containing nitrogen and oxygen atoms in their structures have been disclosed to catalyze transition-metal-free C-H arylation of unactivated arenes with aryl iodides in the presence of tBuOK. In this article, an optimized catalytically active molecule, (2-(methylamino)phenyl)methanol, was designed. A broad range of aryl iodides could be converted into the corresponding arylated products at 100 °C over 24 h with good to excellent yields. Mechanistic experiments verified that radicals participated in this catalytic transformation and that the cleavage of the aromatic C-H bond was not the rate determining step. A K+ capture experiment by 18-crown-6 emphasized the significance of the cation species of the strong base. Fourier transform infrared spectroscopy proved that the catalytic system was activated by the hydrogen bonds between small organic molecules and tBuOK. Also, a clear mechanism was proposed. This transition-metal-free method affords a promising system for efficient and inexpensive synthesis of biaryls via a user-friendly approach, as confirmed by scale-up experiments.
- Chen, Suqing,Chen, Wenjun,Chen, Yu,Liu, Zhenghui,Mu, Tiancheng,Wang, Peng,Yan, Zhenzhong
-
-
Read Online
- PdEDTA held in an ionic liquid brush as a highly efficient and reusable catalyst for Suzuki reactions in water
-
(Chemical Equation Presented) An efficient and reusable catalyst with PdEDTA immobilized in an ionic liquid brush and a green procedure have been developed for coupling aryl iodides and bromides with phenylboronic acid. These reactions were conducted in water under aerobic conditions with water-insoluble or even solid aryl halides. The protocol has the advantages of excellent yields, environmental friendliness, and catalyst recyclability. There was no apparent loss of catalyst efficiency until the 10th cycle.
- Wei, Jun-Fa,Jiao, Jiao,Feng, Jin-Juan,Lv, Jing,Zhang, Xi-Ru,Shi, Xian-Ying,Chen, Zhan-Guo
-
-
Read Online
- Mixed phosphite/N-heterocyclic carbene complexes: Synthesis, characterization and catalytic studies
-
A series of mixed P(OR)3/NHC Pd complexes was synthesized and fully characterized. The steric properties of both types of ligands were computationally determined using X-ray data. These structural studies clearly show that N-heterocyclic carbenes modulate their bulkiness with respect to the steric requirements of the coligands. Catalytic studies were performed using this new class of complexes for the Suzuki- Miyaura reaction. It was found that alkoxide or hydroxide bases and/or alcohols were necessary to achieve good catalytic activity. Mechanistic studies were undertaken in order to gain insights into the role of alkoxide groups. These studies suggest that alcohols or alkoxide groups play a major role in the activation of the precatalyst to generate the catalytically active species. Catalytic studies proved these systems to be efficient using 0.1 mol % of Pd loading for the coupling of aryl, benzyl, and heterocyclic chlorides with boronic acids.
- Diebolt, Olivier,Jurcik, Vaclav,Costad, Rosenildo Correa Da,Braunstein, Pierre,Cavallo, Luigi,Nolan, Steven P.,Slawin, Alexandra M. Z.,Cazin, Catherine S. J.
-
-
Read Online
- Palladium-tetraphosphine catalysed cross coupling of aryl bromides with arylboronic acids: Remarkable influence of the nature of the ligand
-
The cis, cis, cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane- [PdCl(C3H5)]2 system catalyses the cross coupling of aryl bromides with arylboronic acids with very high substrate-catalyst ratios in good yields; a turnover number of 28 000 000 can be obtained for the addition of 4-bromobenzophenone to benzeneboronic acid in the presence of this catalyst.
- Feuerstein,Laurenti,Bougeant,Doucet,Santelli
-
-
Read Online
- Green synthesis and characterization of palladium nanoparticles supported on zeolite Y by sonochemical method, powerful and efficient catalyst for Suzuki-Miyaura coupling of aryl halides with phenylboronic acid
-
In this paper, we report effective, useful and environmental compatible ultrasound method for the synthesis of zeolite–Y. Then, the prepared product was composed with palladium nanoparticles by sonication treatment. The prepared zeolite Y–Pd nanoparticles was used as catalyst in Suzuki-Miyaura coupling of aryl halides (Ar-X, X?=?I, Br, Cl, F) with phenylboronic acid. Based on our studies, the prepared zeolite Y-Palladium nanoparticles revealed a high catalytic performance in Suzuki-Miyaura coupling reaction so that aryl fluoride can even react with phenylboronic acid by utilizing this catalyst. The advantages of the use of this catalyst in Suzuki-Miyaura coupling reaction are green solvent, short reaction time, high yields, ligandless and recyclable. Structure and morphology of the synthesized zeolite-Y and zeolite-Y-Palladium nanoparticles were characterized by FT-IR (Fourier transform infrared), XRD (X-ray diffraction), SEM (Scanning electron microscopy), TEM (Transmission electron microscopy), EDX (Energy dispersive analysis of X-ray), BET (Brunauer Emmett Teller) and ICP-MS (Inductively coupled plasma mass spectrometry).
- Tadjarodi, Azadeh,Dehghani, Modarres,Imani, Mina
-
-
Read Online
- Ligand-free Suzuki coupling reaction with highly recyclable ionic palladium catalyst, Ti1-xPdxO2-x (x?=?0.03)
-
We synthesized a recyclable palladium ionic catalyst, Ti0.97Pd0.03O1.97, using a solution combustion method (SCM), and characterized by XRD and Rietveld refinement. The synthesized Pd ionic catalyst is stable, insensitive to moisture and air, and easy to handle. The new catalyst has exhibited a phenomenal result for the Suzuki-Miyaura cross-coupling reaction with a broad substrate scope, and the reaction proceeds in an aqueous medium. The new catalyst proved beneficial and produced excellent yields irrespective of aryl halide used in the reaction (electron-rich or electron-poor or heterocyclic compounds) and shown a turnover frequency (TOF) of 14–25 h?1 for different reactions. The catalyst was coated on a cordierite monolith (Mg2Al4Si5O18), which enhanced the applicability of the catalyst, and made the handling and recycling of the catalyst very easy. Suzuki Miyaura reaction was carried out using both Pd-powder catalysts as well as the Pd-coated honeycomb, which gave almost similar results. We have demonstrated the recyclability of Pd coated cordierite monolith and shown the superiority of the catalyst over the other Pd catalysts for the Suzuki-Miyaura reaction.
- Bhat K, Shrikanth,Lanke, Veeranjaneyulu,Prasad, Jagadeesh Dasappa,Prabhu, Kandikere Ramaiah
-
-
Read Online
- Facile preparation of highly stable and active hybrid palladium nanoparticles: effectual, reusable and heterogeneous catalyst for coupling reactions
-
Palladium nanoparticles were supported on a bed of Fe3O4@-NH2@Murexide using a simple and efficient method, and characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning and transmission elec
- Adib, Mehdi,Yasaei, Zahra,Karimi-Nami, Rahman,Khakyzadeh, Vahid,Veisi, Hojat
-
-
Read Online
- Dihalogen-bridged NHC-palladium(i) dimers: Synthesis, characterisation and applications in cross-coupling reactions
-
A di-iodo-bridged PdI dimer bearing an N-heterocyclic carbene ligand was made accessible via the reduction of [(IPr)PdI2]2 in basic methanol solution. The structural features of [(IPr)PdI]2 were explored by single-crystal X-ray analysis. It was found to be a convenient one-component precatalyst with high activity in Suzuki-Miyaura, Buchwald-Hartwig, and Sonogashira reactions.
- Pirkl, Nico,Del Grosso, Alessandro,Mallick, Bert,Doppiu, Angelino,Goo?en, Lukas J.
-
-
Read Online
- Reductive rearrangement of 5-nitrobicyclo[2.2.1]hept-2-enes. Formation of 3-arylpyridines
-
Treatment of 6-aryl-5-nitrobicyclo[2.2.1]hept-2-enes with tin(II) chloride in refluxing THF or dioxane gave 3-arylpyridines via a deep-seated rearrangement.
- Ho,Ho, Tse-Lok,Liao,Liao, Po-Yau
-
-
Read Online
- Copper-catalyzed Hiyama coupling of (hetero)aryltriethoxysilanes with (hetero)aryl iodides
-
A CuI-catalyzed Hiyama coupling was achieved, which proceeds in the absence of an ancillary ligand for aryl-heteroaryl and heteroaryl-heteroaryl couplings. A P,N-ligand is required to obtain the best product yields for aryl-aryl couplings. In addition to facilitating transmetalation, CsF is also found to function as a stabilizer of the [CuAr] species, potentially generated as an intermediate after transmetalation of aryltriethoxysilanes with Cu I-catalysts in the absence of ancillary ligands.
- Gurung, Santosh K.,Thapa, Surendra,Vangala, Adarsh S.,Giri, Ramesh
-
-
Read Online
- Use of polymer-supported phenyltin for the creation of aryl-aryl or aryl-heteroaryl bonds via Stille cross-coupling reactions
-
An insoluble polymer-supported phenyltin reagent was successfully used in Stille cross-coupling reactions with aryl- and heteroaryl-halides. Cross-coupling products were isolated in good to high yields with very low contamination by tin and palladium residues after removal of the residual supported organotin halide. The regeneration and recyclability of the supported phenyltin reagent were also examined and proved to be possible, but required palladium cleaning of the grafted polymer to be efficient along 4 cycles when Pd(PPh3)4 was used as catalyst.
- Kerric, Gaelle,Le Grognec, Erwan,Zammattio, Fran?oise,Paris, Michael,Quintard, Jean-Paul
-
-
Read Online
- Solvent-free, palladium-catalyzed Suzuki-Miyaura cross-couplings of aryl chlorides with arylboronic acids
-
Pd(MeCN)2Cl2/PCy3 was found to be an efficient catalytic system for the Suzuki-Miyaura cross-couplings of aryl chlorides with arylboronic acids under solvent-free conditions. Furthermore, the presence of the conventional solvents had deleterious effect on the reaction. In the presence of Pd(MeCN)2Cl2, PCy3, and TBAF (tetra-n-butylammonium fluoride), a number of aryl chlorides including heteroaryl chlorides were coupled with arylboronic acids or heteroarylboronic acids smoothly to afford the corresponding products in moderate to excellent yields. Copyright Taylor & Francis Group, LLC.
- Li, Jin-Heng,Deng, Chen-Liang,Xie, Ye-Xiang
-
-
Read Online
- Suzuki-Miyaura coupling reactions using phosphite ligands
-
A new catalytic system based on palladium phosphites for Suzuki coupling reactions of aryl bromides is described. An airstable catalytic system effectively promotes Suzuki couplings of aryl bromides with a range of boronic acids to afford diaryl products in high yields. Georg Thieme Verlag Stuttgart.
- Jang, Mihee,Jo, Youngshin,Oh, Il-Kwon,Jung, Hyun Min,Lee, Sunwoo
-
-
Read Online
- Palladium-catalyzed Stille cross-coupling reaction of aryl chlorides using a pre-milled palladium acetate and XPhos catalyst system
-
A highly active catalyst system based upon a biaryl monophosphine ligand, XPhos, for the palladium-catalyzed Stille reaction has been developed. This method allows for the coupling of aryl chlorides with a range of tributylarylstannanes to produce the corresponding biaryl compounds in good to excellent yields (61-98%) in short reaction times (4 h). Palladium(II) acetate [Pd(OAc)2] and XPhos in a 1:1.1 ratio were milled into a fine powder that was used as pre-catalyst for these reactions.
- Naber, John R.,Buchwald, Stephen L.
-
-
Read Online
- Visible light-mediated direct arylation of arenes and heteroarenes using diaryliodonium salts in the presence and absence of a photocatalyst
-
Diaryliodonium salts have been used as aryl radical sources under visible light-mediated photoredox catalysis. Benzene and a range of heteroarenes are arylated with Ar2I+ in the presence of [Ir(ppy)2(bpy)] PF6 upon irradiation with visible light. When pyrroles are used, the arylation proceeds in the absence of a photoredox catalyst. Both processes are initiated by photoinduced single-electron-transfer to Ar2I+, generating aryl radicals.
- Tobisu, Mamoru,Furukawa, Takayuki,Chatani, Naoto
-
-
Read Online
- Enhanced heterogeneously catalyzed Suzuki-Miyaura reaction over SiliaCat Pd(0)
-
The SiliaCat Pd(0) solid catalyst can be efficiently employed in the Suzuki-Miyaura cross-coupling of an ample variety of haloarenes, including economically viable chloroarenes. The catalyst can be extensively recycled without loss of activity and with low leaching of valued palladium, opening the route to widespread utilization of the method to afford high yields of biaryls devoid of contaminating by-products.
- Pandarus, Valerica,Desplantier-Giscard, Delphine,Gingras, Genevieve,Ciriminna, Rosaria,Demma Carà, Piera,Béland, Fran?ois,Pagliaro, Mario
-
-
Read Online
- A general catalyst for Suzuki-Miyaura and Sonogashira reactions of aryl and heteroaryl chlorides in water
-
We report the synthesis of 2-(3-sulfonatomesityl)-5-sulfonatoindenyl) dicyclohexylphosphine hydrate sodium salt and its use in palladium-catalyzed Suzuki-Miyaura and Sonogashira coupling reactions in water (and biphasic water-organic solvent mixtures) to prepare a variety of functionalized biaryls and aryl alkynes in excellent yield. This journal is the Partner Organisations 2014.
- Peng, Hui,Chen, Ya-Qin,Mao, Shu-Lan,Pi, Yun-Xiao,Chen, You,Lian, Ze-Yu,Meng, Tong,Liu, Sheng-Hua,Yu, Guang-Ao
-
-
Read Online
- C,N-palladacycles containing N-heterocyclic carbene and azido ligands - Effective catalysts for Suzuki-Miyaura cross-coupling reactions
-
Azido-palladacycles containing C,N-donor and N-heterocyclic carbene ligands, [(C,N-L)Pd(N3)(NHC)] [NHC = IPr; 1,3-bis(2,6- diisopropylphenyl)imidazol-2-ylidene], were prepared from (i) IPr and dinuclear PdII azides, [Pd(μ-N3)(C,N-Ln)]2 [C,N-L1H = N,N′-dimethylbenzylamine; C,N-L2H = 2-(2′-thienyl)pyridine; C,N-L3H = azobenzene; C,N-L 4H = 2-(p-tolyl)pyridine], or from (ii) NaN3 and mononuclear PdII chloride, [Pd(Cl)(IPr)(C,N-Ln)], in aqueous solution. The structures of two of these products were determined by X-ray crystallography. The palladacycles showed high catalytic efficiency toward activated and nonactivated aryl bromides (at room temperature) as well as aryl chlorides (at 80 C) in Suzuki-Miyaura cross-coupling reactions. In addition, coupling reactions of aryl chlorides using potassium aryl trifluoroborates instead of phenyl boronic acid gave good-to-excellent product yields. Suzuki-Miyaura cross-coupling reactions of aryl bromides and chlorides with organoboronic acid as well as potassium aryl trifluoroborates catalyzed by C,N-donor palladacycles containing N-heterocyclic carbene (NHC) and azido ligands under various conditions have been performed. Copyright
- Kim, Yong-Joo,Lee, Jung-Hyun,Kim, Taejung,Ham, Jungyeob,Zheng, Zhen Nu,Lee, Soon W.
-
-
Read Online
- Air-Stable Fe3O4@SiO2-EDTA-Ni(0) as an Efficient Recyclable Magnetic Nanocatalyst for Effective Suzuki-Miyaura and Heck Cross-Coupling via Aryl Sulfamates and Carbamates
-
The synthesis of inexpensive and novel air-stable Ni(0) nanoparticles immobilized on the EDTA-modified Fe3O4@SiO2 nanocatalyst was investigated in Suzuki-Miyaura and Heck cross-coupling reactions. This catalytic system displayed a greatly improved substrate scope for the carbon–carbon bond formations starting from a wide range of green and economical electrophiles aryl and heteroaryl carbamates and sulfamates via highly efficient method under mild, operationally simple reaction conditions. The synthesized heterogeneous catalyst was also fully characterized by FT-IR, TEM, XRD, DLS, FE-SEM, UV–Vis, EDX, XPS, TGA, NMR, VSM, ICP and elemental analysis techniques. The heterogeneous magnetic nanocatalyst can easily be recovered by an external magnetic field and reused for the next reactions for at least seven times with negligible leaching of catalyst and no substantial decrement in the activity. All these highlights have made the present protocol an interesting, simple and environmentally benign process with low catalyst loading and easy manipulations.
- Dindarloo Inaloo, Iman,Majnooni, Sahar,Eslahi, Hassan,Esmaeilpour, Mohsen
-
-
Read Online
- Mercaptopropyl-modified mesoporous silica: A remarkable support for the preparation of a reusable, heterogeneous palladium catalyst for coupling reactions
-
The functionalization of SBA-15 with mercaptopropyl trimethoxysilane leads to a material capable of absorbing Pd from organic and aqueous solutions. The resulting Pd-loaded material acts as a catalyst for the Suzuki-Miyaura and Mizoroki-Heck coupling reac
- Crudden, Cathleen M.,Sateesh, Mutyala,Lewis, Roxanne
-
-
Read Online
- 2-Aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent
-
In this article, we have introduced application of 2-aminophenyl diphenylphosphinite as an easily accessible ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent. By using 2-aminophenyl diphenylphosphinite as a ligand and Pd(OAc)2 as the pre-catalyst, structurally different aryl halides (I, Br, Cl) were reacted efficiently with phenylboronic acid in water to produce their corresponding biphenyl products in good to excellent yields under heterogeneous conditions. The catalyst is recyclable and was recycled for seven runs for the reaction of bromobenzene with phenylboronic acid without appreciable loss of its catalytic activity. In this article we have introduced another useful application of 2-aminophenyl diphenylphosphinite as an easily prepared and cheap ligand for heterogeneous palladium-catalyzed Suzuki-Miyaura reaction in water in the absence of any organic co-solvent. By using 2-aminophenyl diphenylphosphinite ligand and Pd(OAc)2 as the pre-catalyst in water, structurally different aryl halides (I, Br, Cl) were efficiently converted to their biphenyl products in good to excellent yields by the reaction with phenyboronic acid under heterogeneous conditions. The heterogeneous catalyst was recyclable and was recycled for several runs for the reaction of bromobenzene with phenylboronic acid.
- Firouzabadi, Habib,Iranpoor, Nasser,Gholinejad, Mohammad
-
-
Read Online
- A NEW SOURCE FOR GENERATION OF BENZYNE AND PYRIDYNE: REACTIONS OF O-HALOPHENYL (OR 3-BROMO-4-PYRIDYL) PHENYL SULFOXIDES WITH GRIGNARD REAGENTS
-
o-Chloro- and o-bromophenyl phenyl sulfoxides and (3-bromo-4-pyridyl) phenyl sulfoxide were treated with Grignard reagents to generate benzyne (or 3,4-pyridyne) in THF.The o-iodophenyl derivative, on the other hand, gave mainly o-(arylsulfinyl)phenyl Grignard reagent.
- Furukawa, Naomichi,Shibutani, Tadao,Fujihara, Hisashi
-
-
Read Online
- Synthesis and characterization of R2PN=P(iBuNCH 2CH2)3N: A new bulky electron-rich phosphine for efficient Pd-assisted Suzuki-Miyaura cross-coupling reactions
-
(Chemical Equation Presented) Pro-azaphosphatrane 1a [P( 1BuNCH2CH2)3N] reacts with iodine under mild conditions to give [IP-(iBuNCH2CH 2)3N]I in excellent yield, which on subsequent reaction with ammonia followed by deprotonation with KOtBu provided HN=P( iBuNCH2CH2)3N (3a) in quantitative yield. Reaction of 3a with R′2PCl afforded sterically bulky electron-rich phosphines of the type R′2PN=P( iBuNCH2CH2)3N (4) [R′ = Ph (4a), iPr (4b), tBu (4c)]. The Pd(OAc)2/4c catalyst system was particularly efficient for the coupling of arylboronic acids with aryl bromides as well as aryl chlorides to give biaryls in excellent yields.
- Kingston, Jesudoss V.,Verkade, John G.
-
-
Read Online
- A highly efficient and recyclable ligand-free protocol for the Suzuki coupling reaction of potassium aryltrifluoroborates in water
-
A highly efficient, recyclable and ligand-free protocol was developed for the Suzuki coupling of aryl halides with potassium aryltrifluoroborates in water using Pd(OAc)2 as a catalyst and Na2CO3 as a base in air. The presence of poly(ethylene glycol) (PEG) was crucial to the efficiency of the protocol. A wide range of functional groups were tolerated under the optimized conditions. Furthermore, the protocol could be extended to the Suzuki coupling of heteroaryl halides with potassium phenyltrifluoroborate, delivering the desired products in moderate to excellent yields. After simple workup, Pd(OAc)2-H2O-PEG could be recycled at least eight times without significant loss in activity. the Partner Organisations 2014.
- Liu, Leifang,Dong, Yan,Tang, Nana
-
-
Read Online
- Efficient coupling of heteroaryl halides with arylboronic acids in the presence of a palladium-tetraphosphine catalyst
-
Cis, cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl) cyclopentane: ·1/2[PdCl(C3H5)]2 system catalyses the Suzuki cross-coupling of heteroaryl halides with a range of arylboronic acids with very high ratio substrate/catalyst in good yields. Substrates such as pyridines, quinolines, thiophenes, an indole, pyrimidines or a furane have been used successfully.
- Feuerstein, Marie,Doucet, Henri,Santelli, Maurice
-
-
Read Online
- Palladium nanoparticles immobilized on EDTA-modified Fe3O4@SiO2 nanospheres as an efficient and magnetically separable catalyst for Suzuki and Sonogashira cross-coupling reactions
-
In this study, a novel heterogeneous palladium catalyst was synthesized by anchoring palladium onto ethylenediaminetetraacetic acid (EDTA)-coated Fe3O4@SiO2 magnetic nanocomposite and used for the Suzuki and Sonogashira cross-coupling reactions. The properties of the magnetic catalyst were characterized by FT-IR, XRD, TEM, FE-SEM, DLS EDX, XPS, N2 adsorption-desorption isotherm analysis, TGA, VSM, elemental analysis and the loading level of Pd in catalyst was measured to be 0.51?mmol/g by ICP. The catalyst was used in Suzuki cross-coupling reactions of various aryl halides, including less reactive chlorobenzenes with phenylboronic acid without any additive or ligand under green conditions. Furthermore, we have reported this recyclable catalytic system for Sonogashira cross-coupling reactions of various aryl halides (I, Br, Cl) under copper and ligand-free conditions in the presence of DMF/H2O (1:2/v:v) as a solvent. The magnetic catalyst could also be separated by an external magnet and reused six times without any significant loss of activity.
- Esmaeilpour, Mohsen,Zahmatkesh, Saeed,Fahimi, Nafiseh,Nosratabadi, Mehran
-
-
Read Online
- Ligand-Free Bioinspired Suzuki–Miyaura Coupling Reactions using Aryltrifluoroborates as Effective Partners in Deep Eutectic Solvents
-
Pd-catalyzed Suzuki–Miyaura cross-coupling between (hetero)aryl halides (Cl, Br, I) and versatile, moisture-stable mono- and bifunctional potassium aryltrifluoroborates proceeded efficiently and chemoselectively in air and under generally mild conditions; a catalyst loading as low as 1 mol % combined with Na2CO3 as a base in choline chloride/glycerol (1:2) deep eutectic solvent (DES) was used as a sustainable and environmentally responsible medium. The catalyst, base, and DES were easily and successfully recycled up to six times with an E-factor as low as 8.74. Valuable biaryls and terphenyl derivatives were furnished in yields of up to 98 %; over 50 reactions were compared and discussed. The methodology was applied for the synthesis of the nonsteroidal anti-inflammatory drugs Felbinac and Diflunisal.
- Dilauro, Giuseppe,García, Sergio Mata,Tagarelli, Donato,Vitale, Paola,Perna, Filippo M.,Capriati, Vito
-
-
Read Online
- Ligand-free Suzuki-Miyaura reactions in PEG 300
-
In this work, we present ligand-free Suzuki cross-coupling reactions in PEG 300 under thermal conditions at 55 °C with good yields of conversion; better results were obtained with low reaction time. In 1 hour, 1-iodo-4-nitrobenzene and phenylboronic acid reached 98% of the yield and 9700 of TON. Better results were obtained with Pd(0) sources. The reaction system was recycled up to three times with good activity.
- Silva, Aires da Concei??o,Senra, Jaqueline Dias,Aguiar, Lucia C.S.,Simas, Alessandro B.C.,Souza, Andréa Luzia F. de,Malta, Luiz Fernando Brum,Antunes
-
-
Read Online
- Combining enabling techniques in organic synthesis: Solid-phase-assisted catalysis under microwave conditions using a stable Pd(II)-precatalyst
-
The catalytic activity of a 2-pyridinealdoxime-based Pd(II)-complex covalently anchored via the oxime moiety to a glass/polymer composite material was evaluated in Suzuki-Miyaura cross-coupling reactions of aryl and heteroaryl halides, including arylchlorides, with aryl and heteroaryl boronic acids both under thermal as well as microwave irradiating conditions in water. The stability and reusability of this Pd-precatalyst is part of the present study.
- Dawood, Kamal M.,Kirschning, Andreas
-
-
Read Online
- Water-soluble and recyclable cyclopalladated ferrocenylimine for Suzuki coupling reaction
-
A series of new water-soluble cyclopalladated ferrocenylimines were designed and prepared. They were efficient catalyst for Suzuki coupling reactions of aryl bromides and phenylboronic acid in neat water under ambient atmosphere. Among of these catalysts, the catalyst (C2D) could be reused for 6 times for the Suzuki coupling reaction of 4-bromotoluene with phenylboronic acid in EtOH/H2O under ambient atmosphere, in which no significant loss activity of C2D was observed. Water-soluble cyclopalladated ferrocenylimine (C2D) could be reused for 6 times for the Suzuki coupling reaction of 4-bromotoluene with phenylboronic acid in water under ambient atmosphere. Copyright
- Li, Yang,Fu, Zhihua,Rao, Lu,Wang, Li,Li, Rui,Li, Tiesheng,Wu, Yangjie
-
-
Read Online
- Cross-coupling between 3-pyridylmagnesium chlorides and heteroaromatic halides
-
Phenyl- and thienylpyridines were prepared by Pd(0)-catalyzed cross-coupling of 3-pyridylmagnesium chlorides with iodobenzene or iodothiophene at room temperature. Starting from bromo and chloro azines and diazines, the Ni(0)-catalyzed reaction proved more suitable to allow the synthesis of pyridylpyridines, pyridylquinolines and pyridyldiazines.
- Bonnet, Véronique,Mongin, Florence,Trécourt, Fran?ois,Breton, Gilles,Marsais, Francis,Knochel, Paul,Quéguiner, Guy
-
-
Read Online
- Palladium-phosphinous acid-catalyzed NaOH-promoted cross-coupling reactions of arylsiloxanes with aryl chlorides and bromides in water
-
(Equation presented) A palladium-phosphinous acid-catalyzed and NaOH-promoted coupling method using arylsiloxanes and aryl halides in water has been developed. The POPd1-catalyzed reaction between aryl chlorides or bromides and arylsiloxanes is compatible with various functional groups and affords biaryls in up to 99% yield. This cross-coupling reaction does not require additives such as surfactants or organic cosolvents and proceeds under air, which greatly facilitates operation and catalyst handling.
- Wolf, Christian,Lerebours, Rachel
-
-
Read Online
- Pd-catalyzed desulfitative and denitrogenative Suzuki-type reaction of arylsulfonyl hydrazides
-
A palladium-catalyzed desulfitative-denitrogenative coupling of arylsulfonyl hydrazides and arylboronic acids with the assistance of catalytic ligands is described. The reaction showed very good selectivity and tolerated a wide range of functionalities without the aid of expensive copper- or silver-based stoichiometric co-oxidants. We have successfully applied this new cross-coupling reaction to the synthesis of terphenyls and OTBN.
- Zhong, Shuangling,Sun, Chenggang,Dou, Sen,Liu, Wencong
-
-
Read Online
- The catalytic activity of a novel recyclable alkoxypalladium complex in Suzuki reaction
-
A novel palladium complex based on N,O-ligand was synthesized, which shows a high catalytic activity in the Suzuki cross-coupling reaction without using any phosphine ligand. More importantly, no significant loss of the catalytic activity was observed after six recycles. We suggest that this catalyst has commercial and industrial potential in the future. Graphical abstract:
- Li, Yabo,Mi, Xia,Huang, Mengmeng,Cai, Ranran,Wu, Yangjie
-
-
Read Online
- Rhodium-catalyzed arylation using arylboron compounds: Efficient coupling with aryl halides and unexpected multiple arylation of benzonitrile
-
(Chemical Equation Presented) The Suzuki-Miyaura-type cross-coupling of arylboron compounds with aryl halides proceeds efficiently in the presence of a rhodium-based catalyst system to produce the corresponding biaryls. Furthermore, it has unexpectedly been observed that the treatment with benzonitrile under similar conditions brings about its multiple arylation, in which nucleophilic arylation on the cyano group and subsequent ortho arylation via C-H bond cleavage are involved.
- Ueura, Kenji,Satoh, Tetsuya,Miura, Masahiro
-
-
Read Online
- Ferrocenyl-palladium complexes in cross-coupling reactions: A comparative study
-
Ferrocenecarboxaldehyde hydrazones were converted into palladium complexes on treatment with sodium tetrachloropalladate. The substitution pattern of the ferrocenylhydrazones was found to have a marked influence on the mode the palladium was attached to the organic moiety. The catalytic activity of the new palladium complexes in cross-coupling reactions was examined in detail, and it was compared with conventional catalyst systems.
- Nagy, Tibor Zs.,Csámpai, Antal,Kotschy, András
-
-
Read Online
- Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
-
A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
- Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
-
p. 208 - 218
(2021/12/29)
-
- 'Awaken' aryl sulfonyl fluoride: a new partner in the Suzuki-Miyaura coupling reaction
-
An example of the activation of the -SO2F group, which is traditionally considered a stable group even in the presence of a transition metal, is described using a novel partner in the Suzuki-Miyaura coupling reaction catalyzed by Pd(OAc)2 and Ruphos as ligands. The products showed good to outstanding yields and broad functional group compatibility under optimal conditions. The sequential synthesis of non-symmetric terphenyls and the gram grade process highlight the approach's synthetic utility. DFT calculations have shown that Pd0 prefers to insert between C-S bonds rather than S-F bonds. This journal is
- Ding, Chengrong,Guan, Chenfei,Miao, Huihui,Zhang, Guofu,Zhao, Yiyong
-
supporting information
p. 3560 - 3564
(2022/03/07)
-
- Decarbonylative Pd-Catalyzed Suzuki Cross-Coupling for the Synthesis of Structurally Diverse Heterobiaryls
-
Heteroaromatic biaryls are core scaffolds found in a plethora of pharmaceuticals; however, their direct synthesis by the Suzuki cross-coupling is limited to heteroaromatic halide starting materials. Here, we report a direct synthesis of diverse nitrogen-containing heteroaromatic biaryls by Pd-catalyzed decarbonylative Suzuki cross-coupling of widely available heterocyclic carboxylic acids with arylboronic acids. The practical and modular nature of this cross-coupling enabled the straightforward preparation of >45 heterobiaryl products using pyridines, pyrimidines, pyrazines, and quinolines in excellent yields. We anticipate that the modular nature of this protocol will find broad application in medicinal chemistry and drug discovery research.
- Blakemore, David C.,Cervantes-Reyes, Alejandro,Chinigo, Gary M.,Smith, Aaron C.,Szostak, Michal
-
supporting information
p. 1678 - 1683
(2022/03/14)
-
- Evaluation of P-bridged biaryl phosphine ligands in palladium-catalysed Suzuki-Miyaura cross-coupling reactions
-
A family of biaryl phosphacyclic ligands derived from phobane and phosphatrioxa-adamantane frameworks is described. The rigid biaryl phosphacycles are efficient for Suzuki-Miyaura cross-coupling of aryl bromides and chlorides. In particular, coupling reactions of the challenging sterically hindered and heterocyclic substrates were viable at room temperature.
- Holzapfel, Cedric W.,Lamola, Jairus L.,Maumela, Munaka Christopher,Moshapo, Paseka T.
-
p. 26883 - 26891
(2021/08/17)
-
- Supported phosphine free bis-NHC palladium pincer complex: An efficient reusable nanocatalyst for Suzuki-Miyaura coupling reaction
-
A periodic mesoporous organosilica material functionalized with a bis-NHC palladium pincer complex was synthesized by sol-gel process. The resulting organic-inorganic hybrid nano material was characterized by XRD, TEM, SEM, TGA analysis, and BET measurements. The hybrid nanomaterial act as highly active catalysts for the Suzuki–Miyaura cross-coupling between deactivated aryl chlorides and phenylboronic acid under heterogeneous and aerobic conditions. The supported catalyst exhibited excellent activity and stability and it could be reused at least ten times without any significant loss of activity. Furthermore, the SEM image revealed that high order mesostructure of the recycled nanocatalyst. After ninth run, catalyst showed almost similar structure as compared to the fresh catalyst. ICP-AES detected no Pd contamination in the products, and leaching tests verified that the reaction was truly heterogeneous.
- Burange, Anand S.,Luque, Rafael,Rajabi, Fatemeh,Voskressensky, Leonid G.
-
-
- Ligand-to-metal charge transfer of a pyridine surface complex on TiO2for selective dehydrogenative cross-coupling with benzene
-
Dehydrogenative cross-coupling (DCC) between pyridine and benzene proceeded selectively using a TiO2 photocatalyst under visible light irradiation at optimized concentrations of the substrates. Visible light induces ligand-to-metal charge transfer (LMCT) between pyridine and a TiO2 surface to give a pyridine radical cation, which produces a pyridyl radical by its deprotonation or oxidation of another pyridine molecule. The pyridyl radical attacks a benzene ring to form an sp2C-sp2C bond and a hydrogen atom is subsequently removed to complete DCC. Selective excitation of the pyridine LMCT complex in the presence of an excess amount of benzene would be the key for higher selectivity. This journal is
- Hishitani, Shinichiro,Naniwa, Shimpei,Yamamoto, Akira,Yoshida, Hisao
-
p. 11366 - 11373
(2021/05/31)
-
- New biomaterials for Ni biosorption turned into catalysts for Suzuki-Miyaura cross coupling of aryl iodides in green conditions
-
In parallel with increasing Ni production and utilisation, Ni pollution in the soil-water continuum has become an alarming and global problem. Solutions for removing Ni from industrial effluents have been widely investigated and biosorption has emerged as an efficient, cost-effective, scalable and sustainable alternative for water treatment. However, the biosorption capacity is limited by the chemical composition of the biomaterial and the Ni-enriched biomaterials are rarely valorised. In this work, the biosorption capacity of three abundant biomaterials with different chemical properties - water hyacinth, coffee grounds and pinecones - was studied before and after functionalization, and reached a maximum biosorption capacity of 51 mg g?1of Ni(ii). A bioinspired functionalization approach was investigated introducing carboxylate moieties and was conducted in green conditions. The Ni-enriched biomaterials were valorised by transformation into catalysts, which were characterised by MP-AES and XRPD. Their characterisation revealed a structure similar to nickel formate, and hence the Eco-Ni(HCOO)2catalysts were tested in Suzuki-Miyaura reactions. Several aryl iodides were successfully cross-coupled to phenylboronic acids using Eco-Ni(HCOO)2without any ligand, a mild and green base in a mixture of green solvents.
- Adler, Pauline,Boulanger, Clotilde,Cases, Lucie,Diliberto, Sébastien,Grison, Claude,Pelissier, Franck
-
p. 28085 - 28091
(2021/09/15)
-
- Inhibition of (dppf)nickel-catalysed Suzuki-Miyaura cross-coupling reactions by α-halo-N-heterocycles
-
A nickel/dppf catalyst system was found to successfully achieve the Suzuki-Miyaura cross-coupling reactions of 3- and 4-chloropyridine and of 6-chloroquinoline but not of 2-chloropyridine or of other α-halo-N-heterocycles. Further investigations revealed that chloropyridines undergo rapid oxidative addition to [Ni(COD)(dppf)] but that α-halo-N-heterocycles lead to the formation of stable dimeric nickel species that are catalytically inactive in Suzuki-Miyaura cross-coupling reactions. However, the corresponding Kumada-Tamao-Corriu reactions all proceed readily, which is attributed to more rapid transmetalation of Grignard reagents.
- Burton, Paul M.,Cooper, Alasdair K.,Donohoe, William,Greaves, Megan E.,Kennedy, Alan R.,Nelson, David J.,Ronson, Thomas O.
-
p. 14074 - 14082
(2021/11/12)
-
- Aerobic Cu and amine free Sonogashira and Stille couplings of aryl bromides/chlorides with a magnetically recoverable Fe3O4@SiO2 immobilized Pd(II)-thioether containing NHC
-
Two value added C–C cross coupling reactions; Sonogashira and Stille couplings were achieved at milder conditions in the catalytic presence of a magnetically recoverable heterogeneous catalyst Fe3O4@SiO2@NHC^SPh-Pd(II). The catalyst was earlier reported for Suzuki-Miyaura reaction, and as an extension of its catalytic efficiency, the Stille and Sonogashira cross coupling reactions under aerobic condition has been explored in present report. The Sonogashira coupling of aryl bromides and terminal alkynes produced an excellent yield (~96% at 0.25 mol% Pd) of the desired coupling product under copper and amines free conditions. Moreover, an excellent Stille coupling of readily available and more latent aryl chlorides and trialkylstannane was obtained (yields up to 95% at 0.25 mol% Pd) in absence of toxic fluorides additives. The broad substrate scope of the catalyst for both the coupling reactions and the magnetically recoverable feature of catalyst make this reaction highly desirable for industrial applications of present heterogeneous catalysis.
- Khandaka, Himanshu,Sharma, Kamal Nayan,Joshi, Raj Kumar
-
supporting information
(2021/02/20)
-
- Fe3O4-SAHPG-Pd0 nanoparticles: A ligand-free and low Pd loading quasiheterogeneous catalyst active for mild Suzuki–Miyaura coupling and C-H activation of pyrimidine cores
-
This paper reports a green magnetic quasiheterogeneous efficient palladium catalyst in which Pd0 nanoparticles have been immobilized in self-assembled hyperbranched polyglycidole (SAHPG)-coated magnetic Fe3O4 nanoparticles (Fe3O4-SAHPG-Pd0). This catalyst has been used for effective ligandless Pd catalyzed Suzuki–Miyaura coupling reactions of different aryl halides with substituted boronic acids at room temperature and in aqueous media. Herein, SAHPG is used as support; it also acts as a reducing agent and stabilizer to promote the transformation of PdII to Pd0 nanoparticles. Also, this environmental friendly quasiheterogeneous catalyst is employed for the first time in the synthesis of new pyrimido[4,5-b]indoles via oxidative addition/C-H activation reactions on the pyrimidine rings, which were obtained with higher yield and faster than when Pd(OAc)2 was used as the catalyst. Interestingly, the above-mentioned catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnet device and recycled several times with no significant decrease in the catalytic activity.
- Azizollahi, Hamid,Eshghi, Hossein,García-López, José-Antonio
-
-
- Photoelectric properties of aromatic triangular tri-palladium complexes and their catalytic applications in the Suzuki-Miyaura coupling reaction
-
The photoelectric properties and catalytic activities of substituted triphenylphosphine and sulfur/selenium ligand supported aromatic triangular tri-palladium complexes1-4, abbreviated as [Pd3]+, were investigated. The cyclic voltammogram of [Pd3]+in CH3CN-nBu4NPF6showed a single quasi-reversible wave which was consistent with their robust property and provided preliminary proof for their electron transfer processes in catalysis. With excitation at 267 nm, [Pd3]+exhibited strong ratiometric fluorescence at 550 and 780 nm at a temperature gradient from 77 K to 287 K. These peculiar triangular tri-palladium complexes showed excellent catalytic activities and exclusive reactivity with aryl iodides over the other halogenated aromatics in the Suzuki-Miyaura coupling reaction. The electronic and steric hindrance effects of substituents on the aryl iodides and aryl boronic acids including heteroaromatics like pyridine, pyrazine and thiophenes were explored and most substrates achieved up to 99% of yields. (2-[1,1′-Biphenyl]-2-ylbenzothiazole) which was analogous to the selective cyclooxygenase-2 (COX-2) inhibitors was also synthesized with our tri-palladium catalyst and gave good isolated yield (94%). The study of the catalytic process revealed that the mechanism of the reaction may involve the replacement of the sulphur ligand on [Pd3]+by iodine from aryl iodides, which was beneficial for the matching of C-I bond energy.
- Li, Jia,Li, Xujun,Liu, Xiang,Maestri, Giovanni,Malacria, Max,Wang, Xiaoshuang,Wang, Yanlan,Wu, Lingang
-
supporting information
p. 11834 - 11842
(2021/09/06)
-
- Magnetic covalently immobilized nickel complex: A new and efficient method for the Suzuki cross-coupling reaction
-
In this study, an efficient procedure was reported to prepare Fe3O4@SiO2 magnetic nanoparticles (MNPs) with immobilized nickel NPs. In order to increase the activity of this catalyst, creatine as a ligand with high content of nitrogen atoms was linked onto the magnetic core–shell structure. Then, Ni(II) ions were coordinated on the surface of the silica-coated MNPs and reduced to Ni(0) NPs to obtain the final catalyst. The catalytic activity of the prepared catalyst was studied for the synthesis of biaryl derivatives via the Suzuki–Miyaura cross-coupling reaction in high yields. The catalyst could also be recovered and reused with no loss of activity over five successful runs.
- Keyhaniyan, Mahdi,Khojastehnezhad, Amir,Eshghi, Hossein,Shiri, Ali
-
-
- Cobalt-Catalyzed Coupling of Aryl Chlorides with Aryl Boron Esters Activated by Alkoxides
-
The cobalt-catalyzed Suzuki biaryl cross-coupling of aryl chloride substrates with aryl boron reagents, activated with more commonly used bases, remained a significant unmet challenge in the race to replace platinum group metal catalysts with Earth-abundant metal alternatives. We now show that this highly desirable process can be realized using alkoxide bases, provided the right counterion is employed, strict stoichiometric control of the base is maintained with respect to the aryl boron reagent, and the correct boron ester is selected. Potassium tert-butoxide works well, but any excess of the base first inhibits and then poisons the catalyst. Lithium tert-butoxide performs very poorly, while even catalytic amounts of lithium additives also poison the catalyst. Meanwhile, a neopentane diol-based boron ester is required for best performance. As well as delivering this sought-after transformation, we have undertaken detailed mechanistic and computational investigations to probe the possible mechanism of the reaction and help explain the unexpected experimental observations.
- Tailor, Sanita B.,Manzotti, Mattia,Smith, Gavin J.,Davis, Sean A.,Bedford, Robin B.
-
p. 3856 - 3866
(2021/04/07)
-
- Highly Chemoselective Deoxygenation of N-Heterocyclic N-Oxides Using Hantzsch Esters as Mild Reducing Agents
-
Herein, we disclose a highly chemoselective room-temperature deoxygenation method applicable to various functionalized N-heterocyclic N-oxides via visible light-mediated metallaphotoredox catalysis using Hantzsch esters as the sole stoichiometric reductant. Despite the feasibility of catalyst-free conditions, most of these deoxygenations can be completed within a few minutes using only a tiny amount of a catalyst. This technology also allows for multigram-scale reactions even with an extremely low catalyst loading of 0.01 mol %. The scope of this scalable and operationally convenient protocol encompasses a wide range of functional groups, such as amides, carbamates, esters, ketones, nitrile groups, nitro groups, and halogens, which provide access to the corresponding deoxygenated N-heterocycles in good to excellent yields (an average of an 86.8% yield for a total of 45 examples).
- An, Ju Hyeon,Kim, Kyu Dong,Lee, Jun Hee
-
supporting information
p. 2876 - 2894
(2021/02/01)
-
- Metal-Free Deoxygenation of Amine N-Oxides: Synthetic and Mechanistic Studies
-
We report herein an unprecedented combination of light and P(III)/P(V) redox cycling for the efficient deoxygenation of aromatic amine N-oxides. Moreover, we discovered that a large variety of aliphatic amine N-oxides can easily be deoxygenated by using only phenylsilane. These practically simple approaches proceed well under metal-free conditions, tolerate many functionalities and are highly chemoselective. Combined experimental and computational studies enabled a deep understanding of factors controlling the reactivity of both aromatic and aliphatic amine N-oxides.
- Lecroq, William,Schleinitz, Jules,Billoue, Mallaury,Perfetto, Anna,Gaumont, Annie-Claude,Lalevée, Jacques,Ciofini, Ilaria,Grimaud, Laurence,Lakhdar, Sami
-
p. 1237 - 1242
(2021/06/01)
-
- Cobalt-catalyzed cross-coupling reactions of aryl- And alkylaluminum derivatives with (hetero)aryl and alkyl bromides
-
A simple cobalt complex, such as Co(phen)Cl2, turned out to be a highly efficient and cheap precatalyst for a host of cross-coupling reactions involving aromatic and aliphatic organoaluminum reagents with aryl, heteroaryl and alkyl bromides. New C(sp2)-C(sp2) and C(sp2)-C(sp3) bonds were formed in good to excellent yields and with high chemoselectivity, under mild reaction conditions.
- Dilauro, Giuseppe,Messa, Francesco,Bona, Fabio,Perrone, Serena,Salomone, Antonio
-
supporting information
p. 10564 - 10567
(2021/10/19)
-
- Tetrabutylphosphonium 4-ethoxyvalerate as a biomass-originated media for homogeneous palladium-catalyzed Hiyama coupling reactions
-
The introduction of a biomass-derived ionic liquid into the Hiyama coupling reactions, which has been considered as a powerful tool for the synthesis of symmetrically and non-symmetrically substituted biaryl structures, could further control or even reduce the environmental impact of this transformation. It was shown that tetrabutylphosphonium 4-ethoxyvalerate, a γ-valerolactone-based ionic liquid, can be utilized as an alternative solvent to create carbon–carbon bonds between aryl iodides and functionalized organosilanes in the presence of 1?molpercent Pd under typical Hiyama conditions (130?°C, 24?h, tetrabutylammonium fluoride activator). A comparison of different ionic liquids was performed, and the effects of the catalyst precursor and the moisture content of the reaction mixture on the activity of the catalyst system were investigated. The functional group tolerance was also studied, resulting in 15 cross-coupling products (3a–o) with isolated yields of 45–72percent and excellent purity (' 98percent).
- Orha, László,Papp, ábrahám,Tukacs, József M.,Kollár, László,Mika, László T.
-
p. 4593 - 4598
(2020/07/28)
-
- Activator-Promoted Aryl Halide-Dependent Chemoselective Buchwald-Hartwig and Suzuki-Miyaura Type Cross-Coupling Reactions
-
Herein, we report the development of aryl halide-dependent chemoselective reactions, viz., the Buchwald-Hartwig type coupling reaction of an aryl iodide with an arylboronic acid and an aryl amine in the presence of a heterogeneous and reusable nickel catalyst and the Suzuki-Miyaura type coupling of an aryl chloride under similar conditions. Control experiments revealed that the presence of stoichiometric amounts of the phenylboronic acid/ester and aryl amine are essential for both reactions. NMR and XAFS studies suggested the formation of a boron-amine "ate"complex.
- Dhital, Raghu N.,Hashizume, Daisuke,Hu, Hao,Ishii, Rikako,Sato, Takuma,Sen, Abhijit,Takaya, Hikaru,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
-
supporting information
(2020/06/29)
-
- A Convoluted Polyvinylpyridine-Palladium Catalyst for Suzuki-Miyaura Coupling and C?H Arylation
-
The development of highly active and reusable supported catalysts for Suzuki-Miyaura coupling and catalytic C?H arylation is important for fundamental and applied chemistry, with these reactions being used to produce medical compounds and functional materials. Herein, we found that a mesoporous composite made of a linear poly(4-vinylpyridine) and tetrachloropalladate acted as a dual-mode catalyst for a variety of cross-coupling reactions, with both Pd nanoparticles and a Pd complex catalyst being observed under different conditions. The polyvinylpyridine-palladium composite 1 was readily prepared via the molecular convolution of poly(4-vinylpyridine) and sodium tetrachloropalladate to provide a hardly soluble polymer-metal composite. The Suzuki-Miyaura coupling and the C?H arylation of aryl chlorides and bromides with arylboronic acids, thiophenes, furans, benzene, and anisole proceeded in the presence of 0.004 mol% (40 mol ppm) to 1 mol% Pd of 1 to afford the corresponding coupling products in high yields. Furthermore, the catalyst was reused without an appreciable loss of activity. Pharmaceutical compounds and functional materials were synthesized via the coupling reactions. N2 gas adsorption/desorption analysis indicated that the catalyst had a mesoporous nature, which played a crucial role in the catalysis. In the Suzuki-Miyaura couplings, in situ generated palladium nanoparticles in the polymer matrix were catalytically active, while a polymeric Pd(II) complex was crucial in the C?H arylations. These catalytic species were investigated via XAFS, XPS, far-infrared absorption, and Raman spectroscopies, as well as DFT calculations. (Figure presented.).
- Ohno, Aya,Sato, Takuma,Mase, Toshiaki,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
-
supporting information
p. 4687 - 4698
(2020/09/07)
-
- Synthesis of water soluble Pd-Piperidoimidazolin-2-ylidene complexes and their catalytic activities in neat water
-
Through the strategy of water soluble N-heterocyclic carbene (NHC) ligand, Pd-catalyzed reactions were developed in aqueous media. Therefore, four new piperidoimidazolinium salts (1a-d) consisting of sulfonate (a), esther (b, c) and carboxylic acid (d) functionalities and their water-soluble Pd-NHC complexes (2a-d) were synthesized. The new compounds were characterized by elemental analysis, FTIR, TGA, UV–vis and NMR spectroscopy. The catalytic activities of water soluble Pd-NHC complexes (2a-d) were investigated using the Suzuki-Miyaura (S-M) reaction and the reduction of nitroarenes. We found that the water-soluble polar or ionic groups on piperidoimidazolin-2-ylidine had an effect on the catalytic activity. The water-soluble catalyst can be recycled efficiently and reused six times with only a very slight loss of catalytic activity.
- ?ak?r, Sinem,Türkmen, Hayati
-
-
- Synthesis and catalytic activities of Ni complexes bearing a novel N–C–N pincer ligand containing NHC with a bicyclic motif
-
A novel N–C–N pincer ligand bearing an NHC with a bicyclic framework, namely NHC(CH2Py)2, was developed and successfully applied to the syntheses of air- and moisture-stable silver and nickel complexes. The silver complex was identified as {[NHC(CH2Py)2]2Ag}+(AgCl2)–, and the AgCl2 anion was coordinated with one of four pyridines. Transmetallation from silver to nickel using NiCl2(PPh3)2 in toluene and a subsequent anion exchange gave us {[NHC(CH2Py)2]NiCl}+(PF6)– and {[NHC(CH2Py)2]NiCl}+(BF4)– in good yields. These complexes were active and highly stable catalysts when used for Kumada-Tamao-Corriu coupling between 3-bromo-/3-chloropyridine and PhMgBr.
- Ando, Shin,Ishizuka, Tadao,Matsunaga, Hirofumi,Nakano, Nozomi
-
-
- Shuttling Catalyst: Facilitating C?C Bond Formation via Cross-Couplings with a Thermoresponsive Polymeric Ligand
-
A poly(ethylene glycol) (PEG) linked ortho-MeO-phenyldicyclohexylphosphine (MeO-WePhos) ligand has been synthesized to promote Pd-catalyzed carbon-carbon bond formation by cross-couplings including Sonogashira, Heck, Hiyama and Stille reactions, providing corresponding (hetero)aryl substituted alkynes, alkenes and bi(hetero)aryls in good to excellent isolated yields with low Pd loadings. Facilitated by the lower critical solution temperature behaviour of the polymeric monophosphine ligand, the metal-complex could rapidly shuttle between organic and water phases as regulated by temperature, enabling highly efficient catalyst recycling via a simple phase separation. The chemical structure of ligand was determined by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, nuclear magnetic resonance spectrometry and size-exclusion chromatography measurements. Notably, as demonstrated by the inductively coupled plasma-atomic emission spectrometry measurement, 98% Pd was kept in the water phase after 6 cycles of catalyst recycling experiments. Given the profound impact of transition-metal-catalyzed covalent bond formation and the increasing demand of sustainable chemistry, this work provides an alternative method to conduct cross-couplings with a polymeric shuttling catalyst.
- Wang, Erfei,Zhang, Jiawei,Zhong, Zhuoran,Chen, Kaixuan,Chen, Mao
-
p. 419 - 423
(2020/01/08)
-
- A new approach to large scale production of dimethyl sulfone: A promising and strong recyclable solvent for ligand-free Cu-catalyzed C-C cross-coupling reactions
-
Dimethyl sulfone (DMSN) was easily prepared through efficient oxidation of dimethyl sulfoxide (DMSO) and used as a strong and green solvent for organic reactions. A mixture of HNO3/NaOCl was used as an oxidizing agent for efficient oxidation of DMSO to DMSN. The effect of DMSN was evaluated for copper-catalyzed coupling reactions. It is worth noting that DMSN could play the role of a ligand for copper ions. A general survey was accomplished for various types of C-C cross-coupling reactions catalyzed by CuI in DMSN in the absence of any ligand. Moderate to good yields were achieved for Sonogashira, Heck, and Suzuki cross-coupling reactions. Finally, DMSN was recovered and reused for several consecutive runs without any loss of its activity.
- Cheng, Shen,Wei, Wei,Zhang, Xingyu,Yu, Hewei,Huang, Mingming,Kazemnejadi, Milad
-
p. 2069 - 2076
(2020/04/07)
-
- A Mild Method for Electrochemical Reduction of Heterocyclic N-Oxides
-
Deoxygenation of heteroaromatic N-oxides is commonly accomplished using chemical or enzymatic methods. In this work, we report on an expedient protocol for electrochemical reduction of pyridine N-oxide derivatives under mild conditions. A diverse range of mono- and bis N-oxides were converted into the corresponding nitrogen bases in good yields. Importantly, the method is highly selective towards N-oxides and tolerates challenging halo and nitro substituents in the heteroaromatic ring.
- Fukazawa, Yasuaki,Rubtsov, Aleksandr E.,Malkov, Andrei V.
-
supporting information
p. 3317 - 3319
(2020/05/25)
-
- Organocatalyst in Direct C(sp2)-H Arylation of Unactivated Arenes: [1-(2-Hydroxyethyl)-piperazine]-Catalyzed Inter-/Intra-molecular C-H Bond Activation
-
This article describes the identification of 1-(2-hydroxyethyl)-piperazine as a new, cost-effective, highly efficient organocatalyst, which promotes both inter- A nd intra-molecular direct C(sp2)-H arylations of unactivated arenes in the presence of potassium tert-butoxide. While the inter-molecular C-H arylation of unactivated benzenes with aryl halides (Ar-X; X = I, Br, Cl) toward biaryl syntheses underwent smoothly in the presence of only 10 mol percent organocatalyst, the intra-molecular C-H arylation catalytic system composed of 40 mol percent each of the catalyst and the additive (4-dimethylaminopyridine (DMAP)). The novel catalyst was also able to perform both inter- A nd intra-molecular direct arylations simultaneously in a single pot. The mechanistic studies confirmed the involvement of aryl radical anions and proceeded via a single-electron-transfer (SET) mechanism. The large substrate scope, high functional group tolerance, competition experiments, gram-scale synthesis, and kinetic studies further highlight the importance and versatile nature of the methodology as well as the compatibility of the new catalyst. To the best of our knowledge, this is the first report on any organocatalyst that reported detailed investigations of both inter- A nd intra-molecular direct C(sp2)-H arylations of unactivated arenes in a single representation.
- Yadav, Lalit,Tiwari, Mohit K.,Shyamlal, Bharti Rajesh Kumar,Chaudhary, Sandeep
-
p. 8121 - 8141
(2020/07/16)
-
- Photorelease of Pyridines Using a Metal-Free Photoremovable Protecting Group
-
The photorelease of bioactive molecules has emerged as a valuable tool in biochemistry. Nevertheless, many important bioactive molecules, such as pyridine derivatives, cannot benefit from currently available organic photoremovable protecting groups (PPGs). We found that the inefficient photorelease of pyridines is attributed to intramolecular photoinduced electron transfer (PET) from PPGs to pyridinium ions. To alleviate PET, we rationally designed a strategy to drive the excited state of PPG from S1 to T1 with a heavy atom, and synthesized a new PPG by substitution of the H atom at the 3-position of 7-dietheylamino-coumarin-4-methyl (DEACM) with Br or I. This resulted in an improved photolytic efficiency of the pyridinium ion by hundreds-fold in aqueous solution. The PPG can be applied to various pyridine derivatives. The successful photorelease of a microtubule inhibitor, indibulin, in living cells was demonstrated for the potential application of this strategy in biochemical research.
- Dong, Zaizai,Fang, Xiaohong,Kou, Xiaolong,Tan, Weihong,Tang, Xiao-Jun,Wu, Yayun,Zhang, Zhen,Zhao, Rong,Zhou, Wei
-
supporting information
p. 18386 - 18389
(2020/08/24)
-
- Copper catalysed Gomberg-Bachmann-Hey reactions of arenediazonium tetrafluoroborates and heteroarenediazonium o-benzenedisulfonimides. Synthetic and mechanistic aspects
-
Gomberg-Bachmann-Hey reactions were carried out in the presence of copper as a catalyst and gave rise to biaryls or heterobiaryls in good yields and in mild reaction conditions. A computational study of some key points of the reaction was performed. The results are coherent with the experimental data and confirm some aspects of the mechanism. The reaction free energies for the reduction in benzene by CuI of a set of 40 (hetero)arenediazonium tetrafluoroborates were calculated. Both the experiments and the calculations showed that in the coupling with substituted solvents (toluene, bromobenzene, nitrobenzene and anisole) the binding to the ortho position was always favoured.
- Antenucci, Achille,Barbero, Margherita,Dughera, Stefano,Ghigo, Giovanni
-
-
- Switching from biaryl formation to amidation with convoluted polymeric nickel catalysis
-
A stable, reusable, and insoluble poly(4-vinyl-pyridine) nickel catalyst (P4VP-NiCl2) was prepared through the molecular convolution of poly(4-vinylpyridine) (P4VP) and nickel chloride. We proposed a coordination structure of the Ni center in the precatalyst based on elemental analysis and Ni K-edge XANES, and we confirmed that it is consistent with Ni K-edge EXAFS. The Suzuki?Miyaura-type coupling of aryl halides and arylboronic esters proceeded using P4VP-NiCl2 (0.1 mol % Ni) to give the corresponding biaryl compounds in up to 94% yield. Surprisingly, when the same reaction of aryl halides and arylboronic acid/ester was carried out in the presence of amides, the amidation proceeded predominantly to give the corresponding arylamides in up to 99% yield. In contrast, the reaction of aryl halides and amides in the absence of arylboronic acid/ester did not proceed. P4VP-NiCl2 successfully catalyzed the lactamization for preparing phenanthridinone. P4VP-NiCl2 was reused five times without significant loss of catalytic activity. Pharmaceuticals, natural products, and biologically active compounds were synthesized efficiently using P4VPNiCl2 catalysis. Nickel contamination in the prepared pharmaceutical compounds was not detected by ICP-MS analysis. The reaction was scaled to multigrams without any loss of chemical yield. Mechanistic studies for both Suzuki?Miyaura and amidation were performed.
- Sen, Abhijit,Dhital, Raghu N.,Sato, Takuma,Ohno, Aya,Yamada, Yoichi M.A.
-
p. 14410 - 14418
(2020/12/21)
-
- Ni: Vs. Pd in Suzuki-Miyaura sp2-sp2 cross-coupling: A head-to-head study in a comparable precatalyst/ligand system
-
The Suzuki-Miyaura reaction is a cornerstone method for sp2-sp2 cross-coupling in industry. There has been a concerted effort to enable the use of Ni catalysis as an alternative to Pd in order to mitigate cost and improve sustainability. Despite significant advances, ligand development for Ni-catalyzed Suzuki-Miyaura cross-coupling remains underdeveloped when compared to Pd and, as a consequence, ligands for Ni-catalyzed processes are typically taken from the Pd arena. In this study we evaluate the effect of using a similar Ni and Pd precatalyst based on a common bidentate ligand (dppf) in a head-to-head format for the most common type of biaryl couplings, establishing the practical implications of direct replacement of Pd with Ni, and identifying the potential origins of these observations in a mechanistic context.
- West, Matthew J.,Watson, Allan J. B.
-
supporting information
p. 5055 - 5059
(2019/06/03)
-
- N-Heterocarbene Palladium Complexes with Dianisole Backbones: Synthesis, Structure, and Catalysis
-
A series of palladium N-heterocyclic carbenes (NHCs), complexes C1-C5, bearing dianisole backbones and substituted N-aryl moieties have been synthesized and characterized. The electronic effect as well as the steric environment of the NHC ligands has been assessed. The synthesized palladium complexes were applied for Suzuki-Miyaura cross-coupling reactions under aerobic conditions. The relationship between the catalytic structure and catalytic performance was then extensively investigated. Upon optimizing the reaction conditions, the C4 was found to be highly efficient to catalyze the cross-coupling of (hetero)aryl chlorides with (hetero)arylboronic acids at a 0.1 mol % palladium loading.
- Li, Dong-Hui,He, Xu-Xian,Xu, Chang,Huang, Fei-Dong,Liu, Ning,Shen, Dong-Sheng,Liu, Feng-Shou
-
p. 2539 - 2552
(2019/06/17)
-
- Ferrocenyl palladacycles derived from unsymmetrical pincer-type ligands: Evidence of Pd(0) nanoparticle generation during the Suzuki-Miyaura reaction and applications in the direct arylation of thiazoles and isoxazoles
-
A new family of ferrocenyl-palladacycle complexes Pd(L1)Cl (Pd1) and Pd(L2)Cl (Pd2) were synthesized and characterized by UV-visible, IR, ESI-MS, and NMR spectral studies. The molecular structures of Pd1 and Pd2 were determined by X-ray crystallographic studies. Palladacycle catalyzed Suzuki-Miyaura cross-coupling reactions were investigated utilizing the derivatives of phenylboronic acids and substituted chlorobenzenes. Mechanistic investigation authenticated the generation of Pd(0) nanoparticles during the catalytic cycle and the nanoparticles were characterized by XPS, SEM and TEM analysis. Direct C-H arylation of thiazole and isoxazole derivatives employing these ferrocenyl-palladacycle complexes was examined. The reaction model for the arylation reaction implicating the in situ generation of Pd(0) nanoparticles was proposed.
- Maji, Ankur,Singh, Anshu,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
-
supporting information
p. 17083 - 17096
(2019/11/26)
-
- Ligand-free Suzuki-Miyaura coupling reaction of an aryl chloride using a continuous irradiation type microwave and a palladium nanoparticle catalyst: Effect of a co-existing solid
-
We have explored the effect of a co-existing metal in the ligand-free Suzuki-Miyaura coupling reaction of an aryl chloride, which is promoted by a "continuous irradiation type microwave" and a "palladium nanoparticle catalyst", and found that the co-existing metal affects this reaction due to its absorption ability of microwave energy in the reaction system. We also observed that spiking occurred more frequently in the presence of a co-existing metal.
- Yamada, Makito,Shio, Yasunori,Akiyama, Toshiki,Honma, Tetsuo,Ohki, Yuuta,Takahashi, Naoyuki,Murai, Kenichi,Arisawa, Mitsuhiro
-
p. 4541 - 4549
(2019/08/21)
-
- Visible-Light-Enhanced Suzuki–Miyaura Reactions of Aryl Chlorides in Water with Pd NPs Supported on a Conjugated Nanoporous Polycarbazole
-
The visible-light-enhanced catalytic activation of aryl chlorides for Suzuki–Miyaura cross-coupling (SMC) reactions is highly challenging because of the strength of the C?Cl bond. In this work, palladium nanoparticles (Pd NPs) were grown on a conjugated nanoporous polycarbazole (CNP), named Pd/CNP. The hybrid material Pd/CNP could catalyze the SMC reactions of aryl chlorides with arylboronic acids in water under blue LED irradiation at room temperature with high efficiency. This protocol exhibited good functional group tolerance and the catalyst could be recycled without significant loss of its catalytic activity. CNP not only provided photogenerated electrons to enrich the electron density of the Pd NPs but also generated holes for the activation of the arylboronic acids.
- Guo, Bin,Li, Hong-Xi,Zha, Cheng-Hao,Young, David James,Li, Hai-Yan,Lang, Jian-Ping
-
p. 1421 - 1427
(2019/02/26)
-
- Palladium acetate-catalyzed one-pot synthesis of mono- And disubstitued pyridines
-
A Pd-catalyzed one-pot synthesis of mono- and disubstituted pyridines was developed. The substituted pyridines were obtained from ketones or an aldehyde and 1,3-diaminopropane using a combination of catalytic Pd(OAc)2 and Cu(OAc)2. High-concentration reaction conditions enabled this catalytic reaction to be acid-free.
- Mikami, Shunya,Toyota, Masahiro
-
p. 1315 - 1321
(2019/08/01)
-
- Transition-Metal-Free Desulfinative Cross-Coupling of Heteroaryl Sulfinates with Grignard Reagents
-
A mild cross-coupling reaction of heteroaryl sulfinates with Grignard reagents has been developed under transition-metal-free conditions. This study provides an example of the SO22- as a leaving group in an aromatic system and an effective methodology for the construction of C-C bond.
- Wei, Jun,Liang, Huamin,Ni, Chuanfa,Sheng, Rong,Hu, Jinbo
-
-
- Highly-chemoselective step-down reduction of carboxylic acids to aromatic hydrocarbons: Via palladium catalysis
-
Aryl carboxylic acids are among the most abundant substrates in chemical synthesis and represent a perfect example of a traceless directing group that is central to many processes in the preparation of pharmaceuticals, natural products and polymers. Herein, we describe a highly selective method for the direct step-down reduction of carboxylic acids to arenes, proceeding via well-defined Pd(0)/(ii) catalytic cycle. The method shows a remarkably broad substrate scope, enabling to direct the classical acyl reduction towards selective decarbonylation by a redox-neutral mechanism. The utility of this reaction is highlighted in the direct defunctionalization of pharmaceuticals and natural products, and further emphasized in a range of traceless processes using removable carboxylic acids under mild, redox-neutral conditions orthogonal to protodecarboxylation. Extensive DFT computations were conducted to demonstrate preferred selectivity for the reversible oxidative addition and indicated that a versatile hydrogen atom transfer (HAT) pathway is operable.
- Liu, Chengwei,Qin, Zhi-Xin,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
-
p. 5736 - 5742
(2019/06/18)
-
- Synthesis of heterobiaryls via Suzuki-Miyaura coupling reaction of potassium aryltrifluoroborates with heteroaryl halides in aqueous systems
-
A variety of heterobiaryl compounds have been synthesized by the Suzuki-Miyaura coupling reactions of heteroaryl halides with potassium aryltrifluoroborates. Pd (OAc)2 was found to be highly efficient for the Suzuki-Miyaura coupling reactions of various heteroaryl halides with potassium aryltrifluoroborates in aqueous systems, delivering the corresponding heterobiaryl compounds in good to excellent yields.
- Liu, Leifang,Zhao, Kai,Li, Wenbo,Liu, Mingli,Chen, Yuting,Dong, Yan
-
-
- A Bipyridine-Palladium Derivative as General Pre-Catalyst for Cross-Coupling Reactions in Deep Eutectic Solvents
-
A versatile and DES-compatible bipyridine palladium complex has been developed as a general pre-catalyst for different cross-coupling reactions (Hiyama, Suzuki-Miyaura, Heck-Mizoroki and Sonogashira) in deep eutectic solvents. Hydrogen bond capacity of the ligand allows to keep the excellent level of results previously obtained in classical organic solvents. Palladium pre-catalyst showed a high catalytic activity for many cross-coupling reactions, demonstrating a great versatility and applicability. Also, this methodology employs sustainable solvents as a reaction medium and highlights the potential of DES as alternative solvents in organometallic catalysis. The catalyst and DES were easily and successfully recycled. The formation of PdNPs in DES has been confirmed by TEM and XPS analysis and their role as catalyst by mercury test. The dynamic coordination of bipyridine-type ligand in the palladium complex formation has been studied via UV/Vis. (Figure presented.).
- Saavedra, Beatriz,González-Gallardo, Nerea,Meli, Alessandro,Ramón, Diego J.
-
supporting information
p. 3868 - 3879
(2019/07/12)
-
- Polar functional groups anchored to a 2D MOF template for the stabilization of Pd(0) nps for the catalytic C-C coupling reaction
-
A 2D porous MOF, {[Cu(1,2,3-btc)(bpe)(H2O)]·H2O}n (1), has been synthesized using a mixed linker system. The structural determination showed non-coordinated carboxylate groups decorating the pore surface. The desolvated MOF (1a) with pendant carboxylate groups was used as a template for the stabilization of Pd nps (2-3 nm) and the resulting composite Pd(0)@1a showed efficient catalytic activity for the Suzuki-Miyaura C-C coupling reaction.
- Adalikwu, Stephen Adie,Mothika, Venkata Suresh,Hazra, Arpan,Maji, Tapas Kumar
-
supporting information
p. 7117 - 7121
(2019/06/06)
-
- Sterically hindered N-heterocyclic carbene/palladium(ii) catalyzed Suzuki-Miyaura coupling of nitrobenzenes
-
Palladium-catalyzed denitrative Suzuki coupling of nitroarenes using 2-aryl-5-(2,4,6-triisopropylphenyl)-2,3-imidazolylidene[1,5-a]pyridines as the ligands is described. The key to success is the use of the NHC ligands which show strong donating ability and suitable steric hindrance allowing the successful oxidative addition of Ar-NO2 bonds. Both aromatic and aliphatic boronic acids are tolerated, and a variety of biphenyls and alkylarenes were obtained in good to excellent yields.
- Chen, Kai,Chen, Wei,Yi, Xiaofei,Chen, Wanzhi,Liu, Miaochang,Wu, Huayue
-
supporting information
p. 9287 - 9290
(2019/08/08)
-
- Method for synthesizing aromatic compound by coupling palladium/imidazole salt with nitroaromatic hydrocarbon and boric acid compound (by machine translation)
-
The invention discloses a method, for coupling a palladium/imidazole salt with a nitroaromatic hydrocarbon and a boric acid compound to synthesize an aromatic compound. The method comprises: in organic solvent, taking nitroaromatic hydrocarbon and boric acid compound as substrate, palladium/imidazole salt as a catalyst, carrying out coupling reaction under the action of alkali, and carrying out post-treatment to obtain the aromatic compound. The method is simple, easy to store, low in price, relatively low in ligand consumption, high in product yield, good in substrate applicability, and suitable for alkyl boronic acid. The process of the invention can be used to synthesize a series of aromatic compounds, for example. The compound has wide application value in the fields of pesticides, medicines, materials and the like. (by machine translation)
- -
-
Paragraph 0089-0093
(2019/10/01)
-
- METHOD FOR PRODUCING AROMATIC COMPOUND
-
PROBLEM TO BE SOLVED: To provide a novel technique for the production of an aromatic compound. SOLUTION: A method for producing an aromatic compound includes a cross-coupling reaction of an aromatic nitro compound, an aromatic compound represented by general formula (1), a cyanating agent, or a trifluoromethylation agent, in the presence of a catalyst containing an N-heterocyclic carbene compound and a metal compound. (In the general formula (1), Ar1 is an optionally substituted aromatic hydrocarbon group or an optionally substituted hetero aromatic group. M is B(OR1)2 or the like. R1 is a hydrogen atom, a C1-4 alkyl group, or an optionally substituted phenyl group. Two R1 of B(OR1)2 may be the same or different. Two R1 may integrally form a ring containing an oxygen atom and a boron atom). SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
- -
-
Paragraph 0103; 0106
(2019/11/13)
-
- A Supramolecular Palladium Catalyst Displaying Substrate Selectivity by Remote Control
-
Inspired by enzymes such as cytochrome P-450, the study of the reactivity of metalloporphyrins continues to attract major interest in the field of homogeneous catalysis. However, little is known about benefitting from the substrate-recognition properties of porphyrins containing additional, catalytically relevant active sites. Herein, such an approach is introduced by using supramolecular ligands derived from metalloporphyrins customized with rigid, palladium-coordinating nitrile groups. According to different studies (NMR and UV/Vis spectroscopy, XRD, control experiments), the supramolecular ligands are able to accommodate pyridine derivatives as substrates inside the porphyrin pocket while the reactivity occurs at the peripheral side. By simply tuning a remote metal center, different binding events result in different catalyst reactivity, and this enzyme-like feature leads to high degrees of substrate selectivity in representative palladium-catalyzed Suzuki–Miyaura reactions.
- Zardi, Paolo,Roisnel, Thierry,Gramage-Doria, Rafael
-
p. 627 - 634
(2019/01/04)
-