- Acceptorless dehydrogenation of primary alcohols to carboxylic acids by self-supported NHC-Ru single-site catalysts
-
The acceptorless dehydrogenation of diverse aromatic and aliphatic primary alcohols to corresponding carboxylic acids has been accomplished by self-supported NHC-Ru single-site catalysts under mild reaction conditions. Besides broad substrates with excellent activity, selectivity and good tolerance to sensitive functional groups, the solid single-site catalyst could be recovered and reused for more than 20 runs without deactivation. Remarkably, up to 1.8 × 104 turnover numbers could be achieved by this newly developed sustainable protocol in gram scale at low catalyst loading, highlighting its potential in industry.
- Yin, Shenxiang,Zheng, Qingshu,Chen, Jie,Tu, Tao
-
p. 165 - 172
(2022/03/23)
-
- 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)
-
- METHOD OF MANUFACTURING BIPHENYLDICARBOXYLIC ACID
-
A method for producing biphenyldicarboxylic acid according to example embodiments of the present invention is to react a biphenyl (biphenyl) with an acyl halide (acyl halide) - based compound to form an agent 1 intermediate. 1 Intermediate and 3 nd amine-based compound are reacted to form a 2 intermediate, and the step 2 intermediate is base-treated. 4,4 ' - Biphenyldicarboxylic acid can be efficiently produced.
- -
-
Paragraph 0115-0118
(2021/05/25)
-
- Electrochemical coupling halobenzene into biphenyl on a reusable Pd nanoparticle-coated carbon-paper electrode at ambient conditions
-
Electrochemical organic synthesis (EOS) employing electrons to directly activate the reactants can readily complete the chemical conversion under mild conditions. Here, it presented an efficient electrochemical coupling halobenzene into biphenyl on a Pd nanoparticle-coated cathode. The biphenyl product can be obtained with a yield up to 77% at 35 mA, 6 h (3.9 F mol?1). In addition, after consecutive fifth run of the coupling reaction, the yield still remained atca.40%, suggesting its considerable recyclable capacity. In addition, the preliminary kinetics studyviathe off-line gas chromatography analysis of the reaction mixture shows a two-section reaction process, including the introduction process (IP) and fast conversion process (FCP). Further, the estimated reaction kinetics constant value of 0.196 min?1for FCP suggests a more effective conversion than that obtained by the previous study. This study adopts a simple way to fabricate a low-cost and reusable Pd electrode, achieving a high-efficiency electrochemical strategy for the Ullmann-type coupling reaction at mild conditions, and holds a great promise to extend this synthesis route to other important organic synthesis.
- Wang, Chao-Nan,Lu, Yong-Heng,Liu, Yue,Liu, Jun,Yang, Yao-Yue,Zhao, Zhi-Gang
-
p. 3997 - 4003
(2021/03/06)
-
- Method for preparing aromatic carboxylic acid compound
-
The invention discloses a method for preparing an aromatic carboxylic acid compound. The method comprises the following steps: 1) heating carbon dioxide and hydrosilane in the presence of a copper catalyst in a reaction medium A; and 2) adding a reaction medium B, aryl halide, a palladium catalyst and a base to the reaction mixture in the step 1), sealing the reaction system, and performing a heating reaction. The method has the advantages that raw materials are simple and easy to obtain, the raw materials are cheap and stable, the catalyst is common, easy to obtain and stable, the reaction conditionsaremild, the aftertreatment is simple, the yield is high, and the like.
- -
-
Paragraph 0141-0143; 0152-0155; 0177
(2020/02/14)
-
- Preparation method of 4,4'-biphenyldicarboxylic acid
-
The invention discloses a preparation method of 4,4'-biphenyldicarboxylic acid, which specifically comprises the following steps: S1, preparation of raw materials, S2, 4,4'-biphenyldicarboxylic acid crude product preparation, S3, reaction mother liquor treatment, S4, 4,4'-biphenyldicarboxylic acid refining pretreatment, and S5, 4,4'-biphenyldicarboxylic acid refining. The invention relates to thetechnical of chemical product preparation and discloses a preparation method of 4,4'-biphenyldicarboxylic acid. A two-stage alkaline water spraying device can be adopted through tail gas absorption toreach standard emission; according to the process, provincial security association safety and reliability argumentation is carried out; in addition, the industrial yield of the reaction reaches 98% or above; the content is 99.5% or above, the yield is high, the quality is good and no pollution is caused to the environment. The purposes of improving the yield and purity of the 4,4'-diphenyldicarboxylic acid and being environmentally friendly are well achieved, and therefore the method is quite beneficial to production of 4, 4'-diphenyldicarboxylic acid production enterprises.
- -
-
Paragraph 0023-0034
(2020/06/02)
-
- Synthesis method for 4,4'-biphenyldicarbox ylic acid
-
The invention discloses a synthesis method for 4,4'-biphenyldicarbox ylic acid. The method comprises the following specific steps: performing radical chlorination on 4,4'-dimethyl biphenyl used as a raw material under the effect of light or an initiator so as to generate 4,4'-di(trichloromethyl)biphenyl; then performing hydrolysis reaction under an alkaline condition so as to obtain 4,4'-biphenyldicarbox ylic acid; and performing an aftertreatment process, thereby obtaining a finished product. The synthesis method for 4,4'-biphenyldicarbox ylic acid is rich in raw material sources, low in rawmaterial price, simple in synthesis process, high in product recovery rate, free from any purification, high in product yield and product purity, less in pollution, high in conversion rate, high in economical efficiency and suitable for industrial large-scale production.
- -
-
Paragraph 0027; 0030; 0031; 0034; 0035; 0038; 0039; 0042
(2019/01/23)
-
- PREPARATION AND USE OF BIPHENYLDICARBOXYLIC ACIDS
-
A process for selective oxidation of at least one dimethylbiphenyl compound to the corresponding biphenyldicarboxylic acid, where the dimethylbiphenyl compound is supplied to at least one reaction zone together with an acidic solvent, an oxidizing medium, and a catalyst comprising cobalt, manganese, and bromine. The dimethylbiphenyl compound and oxidizing medium are contacted with the catalyst in the at least one reaction zone at a temperature of 150 to 210°C to oxidize the dimethylbiphenyl compound to the corresponding biphenyldicarboxylic acid. The supply of dimethylbiphenyl compound to the at least one reaction zone is then terminated, but the supply of oxidizing medium and catalyst is continued with the at least one reaction zone at a temperature of 150 to 210°C. A reaction product comprising at least 95 wt% of the biphenyldicarboxylic acid based on the total weight of oxidized dimethylbiphenyl compound is then recovered from the at least one reaction zone.
- -
-
Paragraph 0057
(2019/08/26)
-
- Tandem one-pot CO2 reduction by PMHS and silyloxycarbonylation of aryl/vinyl halides to access carboxylic acids
-
The present study discloses the synthesis of aryl/vinyl carboxylic acids from Csp2-bound halides (Cl, Br, I) in a carbonylative path by using silyl formate (from CO2 and hydrosilane) as an instant CO-surrogate. Hydrosilane provides hydride for reduction and its oxidation product silanol serves as a coupling partner. Mono-, di-, and tri-carboxylic acids were obtained from the corresponding aryl/vinyl halides.
- Paridala, Kumaraswamy,Lu, Sheng-Mei,Wang, Meng-Meng,Li, Can
-
supporting information
p. 11574 - 11577
(2018/10/31)
-
- In the ionic liquid 4 - chlorobenzene a acid couple preparation biphenyl dicarboxylic acid (by machine translation)
-
The invention discloses a in ionic liquid under the catalysis of the bivalent copper salt to promote the use of samarium skating benzoic acid coupling reaction preparation 4, 4' - biphenyl dicarboxylic acid. Under mixing to the chlorobenzoic acid in [bmim] Cl ionic liquid (chlorinated butyl methyl imidazole) in mixed and dissolved, then adding metal samarium powder, anhydrous copper chloride powder and a small amount of pyridine. The reaction system in the absence of the absence of water. Under stirring at room temperature until the reaction is complete. The resulting reaction mixture liquid to ion liquid recovery. The crude product by column chromatography separation to obtain 4, 4' - biphenyl dicarboxylic acid, recrystallize to get the pure product, yield is 70 - 90%. (by machine translation)
- -
-
Paragraph 0015-0016; 0020; 0022
(2019/01/08)
-
- Organic Solvent-Free, Pd(II)-Salan Complex-Catalyzed Synthesis of Biaryls via Suzuki-Miyaura Cross-Coupling in Water and Air
-
With use of a Pd(II)-sulfosalan complex as a water-soluble catalyst, we have developed an efficient synthesis of biaryls via Suzuki-Miyaura cross-coupling in water under aerobic conditions. The water-insoluble target molecules were isolated by simple filtration in analytical purity after washing with 0.01 M aqueous HCl (20 examples). In most cases, palladium contamination was below 5 ppm considered acceptable for active pharmaceutical ingredients. The established method is scalable, reproducible, and provides biaryl products in isolated yields up to 91%.
- Bunda, Szilvia,Udvardy, Antal,Voronova, Krisztina,Joó, Ferenc
-
p. 15486 - 15492
(2019/01/03)
-
- Introduction of carbonyl groups: An approach to enhance electrochemical performance of conjugated dicarboxylate for Li-ion batteries
-
A rational functionalization of conjugated dicarboxylate is reported here to enhance the cyclability and rate capability for Li-ion batteries. Introduction of carbonyl groups between aromatic rings is explored as an alternative way to extend π-conjugation. For the proof of concept, 4,4′-bis(lithiooxycarbonyl)benzil (Li2-BZL) was synthesized and compared its lithium storage performance against lithium [1,1′-biphenyl]-4,4′-dicarboxylate (Li2-BPDC). The Li2-BZL electrode delivers a stable capacity of 165 mAh g?1 even after 50 cycles at current density of 50 mAh g?1 whereas, rapid capacity fading was observed in the case of Li2-BPDC. Density functional theory (DFT) studies confirmed that the carbonyl groups in the Li2-BZL to reduce the bandgap, thereby improving the elctrochemical lithium storage performance of Li2-BZL electrode in comparision to that of Li2-BPDC.
- Medabalmi, Veerababu,Ramanujam, Kothandaraman
-
p. A1720 - A1725
(2017/06/21)
-
- Effects of length and number of aromatic rings in carboxylic acid ligands on structure and optical properties of lead(II) coordination polymers
-
To systematically examine the effects of the length and number of aromatic rings in carboxylic acid ligands on the structure and properties of lead(II) coordination polymers, terephthalic acid (L1) and 4,4-biphenyl dicarboxylic acid (L2) as primary ligands and 1-(dimethylamino)propan-2-ol (L3) as ancillary ligand were used for preparation of two new lead(II) coordination polymers: [Pb2L2 1L3(DMF)]n (1) and [PbL2L3]n (2). Single-crystal X-ray diffraction analysis was used to determine the crystal structure of the prepared compounds. The results showed that the length of the π-conjugation system of the aromatic carboxylic acid ligands was a primary factor controlling the structure of the coordination compounds. Connecting Pb(II) atoms using ligands L1 and L3 led to formation of compound 1 with two-dimensional network structure, while use of ligands L3 and L2 resulted in formation of compound 2 with zigzag one-dimensional (1D) polymeric network structure. Study of the thermal behavior of the prepared compounds revealed that the structure and type of the ligands in the coordination compounds affected their thermal stability. Investigation of the optical properties of the compounds demonstrated that changing the length of the π-conjugation system of the aromatic carboxylic acid ligands in the structure of the coordination compounds can be used to tune their photophysical properties.
- Hashemzadeh, Alireza,Amini, Mostafa M.,Najafi, Ezzatollah,Khavasi, Hamid Reza
-
p. 5741 - 5753
(2017/09/23)
-
- Linker Installation: Engineering Pore Environment with Precisely Placed Functionalities in Zirconium MOFs
-
Precise placement of multiple functional groups in a highly ordered metal-organic framework (MOF) platform allows the tailoring of the pore environment, which is required for advanced applications. To realize this, we present a comprehensive study on the linker installation method, in which a stable MOF with coordinatively unsaturated Zr6 clusters was employed and linkers bearing different functional groups were postsynthetically installed. A Zr-MOF with inherent missing linker sites, namely, PCN-700, was initially constructed under kinetic control. Twelve linkers with different substituents were then designed to study their effect on MOF formation kinetics and therefore resulting MOF structures. Guided by the geometrical analysis, linkers with different lengths were installed into a parent PCN-700, giving rise to 11 new MOFs and each bearing up to three different functional groups in predefined positions. Systematic variation of the pore volume and decoration of pore environment were realized by linker installation, which resulted in synergistic effects including an enhancement of H2 adsorption capacities of up to 57%. In addition, a size-selective catalytic system for aerobic alcohol oxidation reaction is built in PCN-700 through linker installation, which shows high activity and tunable size selectivity. Altogether, these results exemplify the capability of the linker installation method in the pore environment engineering of stable MOFs with multiple functional groups, giving an unparalleled level of control.
- Yuan, Shuai,Chen, Ying-Pin,Qin, Jun-Sheng,Lu, Weigang,Zou, Lanfang,Zhang, Qiang,Wang, Xuan,Sun, Xing,Zhou, Hong-Cai
-
supporting information
p. 8912 - 8919
(2016/07/30)
-
- Rapid Microwave-Assisted Synthesis of N-Aryl 1,2,3,4-Tetrahydroisoquinolines
-
N-aryl 1,2,3,4-tetrahydroisoquinolines were prepared rapidly in good yields by the microwave-assisted Pd-catalysed coupling of (hetero)aryl iodides or bromides with 1,2,3,4-tetrahydroisoquinoline. Reactions were typically complete within 5 min for aryl iodides and within 30 min for pyridyl bromides.
- Forni, José Augusto,Brzozowski, Martin,Tsanaktsidis, John,Savage, G. Paul,Polyzos, Anastasios
-
p. 1890 - 1893
(2015/12/26)
-
- Cerium-based metal organic frameworks with UiO-66 architecture: Synthesis, properties and redox catalytic activity
-
A series of nine Ce(IV)-based metal organic frameworks with the UiO-66 structure containing linker molecules of different sizes and functionalities were obtained under mild synthesis conditions and short reaction times. Thermal and chemical stabilities were determined and a Ce-UiO-66-BDC/TEMPO system was successfully employed for the aerobic oxidation of benzyl alcohol.
- Lammert, Martin,Wharmby, Michael T.,Smolders, Simon,Bueken, Bart,Lieb, Alexandra,Lomachenko, Kirill A.,De Vos, Dirk,Stock, Norbert
-
supporting information
p. 12578 - 12581
(2015/08/06)
-
- Palladium-catalyzed synthesis of symmetrical biaryls under microwave irradiation and conventional heating
-
The activity of the [Pd{C6H4(CH2N(CH 2Ph)2)}(μ-Br)]2 complex was investigated in the synthesis of symmetrical biaryls under both conventional and microwave irradiation conditions, and their results were compared. This complex is efficient, stable, and not sensitive to air or moisture and is a catalyst for the homo-coupling reaction of aryl iodides, bromides, and even chlorides. The products were produced in excellent yields in short reaction times using a catalytic amount of [Pd{C6H4(CH2N(CH 2Ph)2)(μ-Br)]2 complex in N-methylpyrolidine (NMP) at 130 °C. In comparison to conventional heating conditions, the reactions under microwave irradiation gave better yields in shorter reaction times.
- Hajipour, Abdol Reza,Rafiee, Fatemeh
-
p. 1314 - 1327
(2013/04/10)
-
- Water-dispersable hybrid Au-Pd nanoparticles as catalysts in ethanol oxidation, aqueous phase Suzuki-Miyaura and Heck reactions
-
The catalytic activities of water-dispersable Au@Pd core-shell nanoparticles (NPs) and Au-Pd alloy NPs were examined. There is growing interest in Au-Pd hybridized NPs in a supported matrix or non-supported forms as catalysts in various reactions that are not limited to conventional Pd-related reactions. Four different Au@Pd core-shell NPs in this study were prepared at room temperature with help from the emulsion phase surrounding the Au core NPs. Au-Pd alloy NPs were prepared over 90 °C, and underwent phase transfer to aqueous medium for their catalytic use. Au@Pd core-shell NPs show catalytic activity in ethanol oxidation reactions as electrocatalysts, and both core-shell and alloy NPs are good to excellent catalysts in various Suzuki-Miyaura and Heck reactions as heterogeneous catalysts. Specifically, Au@Pd core-shell NPs with sharp branched arms show the highest yield in the reactions tested in this study. A relatively small amount (0.25 mol%) was used throughout the catalytic reactions.
- Song, Hyon Min,Moosa, Basem A.,Khashab, Niveen M.
-
experimental part
p. 15953 - 15959
(2012/10/18)
-
- Bolaamphiphiles bearing bipyridine as mesogenic core: Rational exploitation of molecular architectures for controlled self-assembly
-
A bolaamphiphile (5,5-B2NBr8) bearing a functional bipyridine moiety as the mesogenic core is reported for the first time. 5,5-B2NBr8 was found to self-assemble into uniform fibrous structure in aqueous solution, when the concentration was higher than cmc. Analogues of 5,5-B2NBr8 with structural differences in chain length, headgroup, mesogenic core, and substituted position were synthesized, elucidating that small variances of the molecular structure could lead to dramatic changes of the resulting assemblies. For example, compound 4,4-B2NBr8 showed only spherical colloidal aggregates rather than fibers as 5,5-B2NBr8 did, while the only difference between them was the position at which the alkyl chains were attached onto bipyridine. A probable model for the fibrous structure of 5,5-B2NBr8 was proposed. Moreover, exploiting the coordination capacity of bipyridine, assembly and disassembly of 5,5-B2NBr8 could be reversibly controlled through the addition of EDTA and Cu(II), respectively.
- Wu, Guanglu,Verwilst, Peter,Xu, Jun,Xu, Huaping,Wang, Ruji,Smet, Mario,Dehaen, Wim,Faul, Charl F. J.,Wang, Zhiqiang,Zhang, Xi
-
scheme or table
p. 5023 - 5030
(2012/06/29)
-
- Homocoupling of arylboronic acids and potassium aryltrifluoroborates catalyzed by protein-stabilized palladium nanoparticles under air in water
-
Palladium nanoparticles stabilized primarily within the protein cavity of a highly thermostable Dps protein (DNA binding protein from starved cells) from the thermophilic bacterium Thermosynechoccus elongatus provide an efficient catalyst for the homocoupling of boronic acids and potassium aryltrifluoroborates in water under aerobic phosphine-free conditions. Symmetrical biaryls have been isolated in good to excellent yields. Potassium aryltrifluoroborates give similar or better results than the corresponding arylboronic acids.
- Prastaro, Alessandro,Ceci, Pierpaolo,Chiancone, Emilia,Boffi, Alberto,Fabrizi, Giancarlo,Cacchi, Sandro
-
experimental part
p. 2550 - 2552
(2010/06/19)
-
- Imidazolium-based phosphinite ionic liquid (IL-OPPh2) as Pd ligand and solvent for selective dehalogenation or homocoupling of aryl halides
-
The use of an imidazolium-based phosphinite ionic liquid (IL-OPPh2) as ligand for Pd offers an efficient reagent system for the selective dehalogenation or homocoupling of aryl halides in the presence of NaOPri or Et3N, respectively. This ionic liquid plays a dual role as both the reaction media and also as the potential complexing agent with Pd via its phosphinite carrying group. The ionic liquid containing its corresponding Pd complex can be easily recovered and reused in several runs.
- Iranpoor, Nasser,Firouzabadi, Habib,Azadi, Roya
-
p. 2469 - 2472
(2008/09/21)
-
- Palladium(II) chloride/EDTA-catalyzed biaryl homo-coupling of aryl halides in aqueous medium in the presence of ascorbic acid
-
Both electron-deficient and electron-rich aryl bromides undergo biaryl homo-coupling in a basic aqueous-ethanolic medium in the presence of PdCl2-EDTA (1:1 molar ratio, 3 mol %) as catalyst and ascorbic acid as reductant (1 mol equiv) in acceptable to good yields.
- Ram, Ram N.,Singh, Virinder
-
p. 7625 - 7628
(2007/10/03)
-
- Optimized liquid-phase oxidation
-
Disclosed is an optimized process and apparatus for more efficiently and economically carrying out the liquid-phase oxidation of an oxidizable compound. Such liquid-phase oxidation is carried out in a bubble column reactor that provides for a highly effic
- -
-
Page/Page column 39-41
(2008/06/13)
-
- Optimized liquid-phase oxidation
-
Disclosed is an optimized process and apparatus for more efficiently and economically carrying out the liquid-phase oxidation of an oxidizable compound. Such liquid-phase oxidation is carried out in a bubble column reactor that provides for a highly effic
- -
-
Page/Page column 39-41
(2008/06/13)
-
- Synthesis of aromatic carboxylic acids by carbonylation of aryl halides in the presence of epoxide-modified cobalt carbonyls as catalysts
-
A new procedure was developed for synthesis of aromatic and heteroaromatic acids and their derivatives (esters, salts) by carbonylation of the corresponding aryl halides. The acids are selectively formed in a high yield under very mild conditions. Highly active catalytic systems, base-containing alcoholic solutions of cobalt carbonyl modified with epoxides, were used to activate aryl halides. 2005 Pleiades Publishing, Inc.
- Boyarskii,Zhesko,Lanina
-
p. 1844 - 1848
(2007/10/03)
-
- Homocoupling of aryl iodides and bromides using a palladium/indium bimetallic system
-
Homocoupling of aryl iodides and bromides using catalytic amounts of palladium and stoichiometric amounts of indium proceeded smoothly to afford the corresponding biaryls in good to high yields. Copyright Taylor & Francis, Inc.
- Chang, Yu Mi,Lee, Seung Hwan,Cho, Min Young,Yoo, Byung Woo,Rhee, Hak June,Lee, Sang Ho,Yoon, Cheol Min
-
p. 1851 - 1857
(2007/10/03)
-
- Aqueous-phase, palladium-catalyzed cross-coupling of aryl bromides under mild conditions, using water-soluble, sterically demanding alkylphosphines
-
Sterically demanding, water-soluble alkylphosphines have been used in combination with various palladium salts in Suzuki, Sonogashira, and Heck couplings of aryl bromides under mild conditions in aqueous solvents. The tert-butyl-substituted ligands 2-(di-tert-butylphosphino)ethyltrimethylammonium chloride (t-Bu-Amphos) and 4-(di-tert-butylphosphino)-N,N-dimethylpiperidinium chloride (t-Bu-Pip-phos) in combination with palladium(II) salts were found to give catalysts that were significantly more active than catalysts derived from tri(3-sulfonatophenyl)phosphine trisodium (TPPTS). Suzuki couplings of unactivated aryl bromides occurred efficiently at room temperature in water/acetonitrile and water/toluene biphasic mixtures or in neat water. Notably, Suzuki couplings of hydrophilic aryl bromides gave high yields without using organic solvents for the reaction or purification. This methodology has been applied to a highly efficient synthesis of diflunisal. The catalyst derived from t-Bu-Amphos was recycled three times in Suzuki couplings in water/toluene before catalyst activity began to significantly drop. The average yield of four cycles was >80% per cycle. Heck and Sonogashira couplings were carried out under mild conditions (50 and 80°C, respectively) with unactivated aryl bromides to give coupled products in high yield.
- DeVasher, Rebecca B.,Moore, Lucas R.,Shaughnessy, Kevin H.
-
p. 7919 - 7927
(2007/10/03)
-
- Facile synthesis of symmetrical functionalized biaryls from aryl halides catalyzed by commercial zinc dust using ammonium formate
-
Reductive homocoupling of aryl halides in the presence of commercial zinc dust and ammonium formate in methanol produces biaryls in good to excellent yields. Aryl halides having either electron-donating or electron-withdrawing groups underwent smooth coupling to afford the corresponding symmetrical biaryls. Addition of 1equiv of sodium hydroxide enhanced the coupling reaction rate. Commercial zinc dust is inexpensive, widely available and can be used without any auxiliary catalysts such as Pd(0) and/or Ni(0).
- Abiraj,Srinivasa,Channe Gowda
-
p. 2081 - 2084
(2007/10/03)
-
- Novel and efficient synthesis of symmetrical functionalized biaryls using zinc and triethylammonium formate
-
Reductive homocoupling of aryl halides in the presence of commercial zinc dust and triethylammonium formate in methanol produces biaryls in good to excellent yields. Aryl halides having either electron-donating or electron-withdrawing groups underwent smooth coupling to afford the corresponding symmetrical biaryls. The reductive coupling did not occur without triethylammonium formate. Addition of one equivalent of sodium hydroxide enhanced the coupling reaction rate. The commercial zinc dust is inexpensive, widely available and can be used without any auxiliary catalysts such as Pd(0) and/or Ni(0).
- Abiraj,Srinivasa,Gowda, D. Channe
-
p. 877 - 879
(2007/10/03)
-
- Heterogeneous Rh/C-catalyzed direct reductive coupling of haloaryls to biaryls in water
-
Reductive coupling of haloaryls and substituted haloaryls to the respective biaryls is effected in water with good selectivity, using a reducing agent such as formate salts and a base, NaOH, in the presence of a catalytic amount of PEG-400 and 5% Rh/C catalyst at 115 °C temperature. The catalyst can be recycled. The competing reduction reaction is minimized with proper alteration of the operating conditions. The role of temperature, catalyst loading, reducing agents, base, and PEG-400 are discussed. The reaction follows a zero-order kinetics.
- Mukhopadhyay, Sudip,Joshi, Ashutosh V.,Peleg, Liat,Sasson, Yoel
-
-
- Transition-metal-free Suzuki-type coupling reactions: Scope and limitations of the methodology
-
The scope and limitations of the transition-metal-free Suzuki-type coupling of aryl halides and arylboronic acids to form biaryls are presented. Confirmation that the reaction is indeed metal-free is presented. The effects of changing base, solvent, reaction temperature, phase-transfer catalyst, and substrate are shown and the implications of these results discussed in terms of their impact on the synthetic versatility of the methodology. The main findings are that the reaction works well for aryl bromides, water is necessary as a solvent for the reaction, the optimum temperature for the reaction is 150 °C, the reaction is best performed by using microwave promotion with the exception of an electron-poor aryl bromide example where conventional heating may be used, only limited boronic acids can be used as coupling partners, sodium carbonate is the best base for the reaction, tetrabutylammonium bromide proves to be the best phase-transfer catalyst for the reaction, the reaction is limited to couplings between aryl halides and aryl boronic acids with sp2-sp3 couplings proving ineffective, and NaBPh4 can be used in the place of phenylboronic acid as a phenylating agent.
- Leadbeater, Nicholas E.,Marco, Maria
-
p. 5660 - 5667
(2007/10/03)
-
- Suzuki cross-coupling reactions using reverse-phase glass beads in aqueous media
-
Reverse-phase glass beads have been employed in Suzuki reactions to provide, in aqueous media, a route to diverse polar substrates in good yield and with low levels of palladium leaching.
- Lawson Daku, Kokovi M.,Newton, Roger F.,Pearce, Simon P.,Vile, Julia,Williams, Jonathan M. J.
-
p. 5095 - 5098
(2007/10/03)
-
- Highly selective and efficient conversion of alkyl aryl and alkyl cyclopropyl ketones to aromatic and cyclopropane carboxylic acids by aerobic catalytic oxidation: A free-radical redox chain mechanism
-
An efficient and convenient method has been developed for the oxidation of aryl alkyl and cyclopropyl alkyl ketones to aromatic and cyclopropane carboxylic acids by molecular oxygen at atmospheric pressure, catalysed by Mn(NQ3)2 in combination with Co(NO3)2 or Cu(NO3)2. This simple, cheap and highly selective process has a general character for the synthesis of carboxylic acids and it is particularly suitable for industrial applications.
- Minisci, Francesco,Recupero, Francesco,Fontana, Francesca,Bj?rsvik, Hans-Rene?,Liguori, Lucia
-
p. 610 - 612
(2007/10/03)
-
- Activation of the C-H bond in DMF as a key stage of oxidative addition of aryl iodides to platinum(II) in the system PtCl2-4-DMF
-
Reaction of mono- and disubstituted aryl iodides with platinum(II) tetrachloride complexes in DMF results in formation of the corresponding arenes and biaryls. With the substrate present in a large excess, biaryl formation becomes a preferred pathway and proceeds catalytically. The rates of the oxidative addition increase in the series of substituents p-CH3O ≈ m-CH3 2 2, and the Hammett equation with the parameters p +1.3±0.2 and logk0 -4.51 ± 0.08 is obeyed. The kinetic data and the composition of the products are in agreement with a mechanism involving initial formation of a PtCl3 · (CONMe2)2- species as a result of activation of the C-H bond in dimethylformamide by platinum(II), followed by oxidative addition of ArI to this species.
- Bezbozhnaya,Litvinenko,Skripnik,Zamashchikov
-
p. 1198 - 1203
(2007/10/03)
-
- The use of Ni(CO)2(PPh3)2 in aryl and pyridyl coupling reactions
-
The zerovalent nickel complex Ni(CO)2(PPh3)2 has been used for the coupling of aryl halides to form biaryls and for the coupling of bromopyridines to form polypyridines. The effects of solvent, halide and substituents have also been investigated.
- Leadbeater, Nicholas E.,Resouly, Sarah M.
-
p. 4243 - 4246
(2007/10/03)
-
- Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 16. Model studies for the construction of conjugated polymers
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Reaction of a range of bis(ylides) with acid chlorides has been used to prepare the bis(oxoylides) 11-15. Similarly a range of simple ylides react with bis(acid chlorides) to give bis(oxoylides) 19-27 with the isomeric structure. Flash vacuum pyrolysis (FVP) of one example of the first type results in extrusion of Ph3P rather than the expected Ph3PO while six examples of the second type do extrude Ph3PO upon FVP at 500 °C to afford the bis(alkynes) 28. Examples of the corresponding bis(tributylphosphonium ylides) have also been prepared but attempts to construct a tetrakis(oxoylide) 31 using a stepwise approach were unsuccessful. Fully assigned 13C NMR spectra are presented for six of the bis(oxoylides).
- Aitken, R. Alan,Drysdale, Martin J.,Hill, Lawrence,Lumbard, Keith W.,Maccallum, James R.,Seth, Shirley
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p. 11039 - 11050
(2007/10/03)
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- Process for introducing a carboxyl group to an aromatic carboxylic acid or a derivative thereof
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Disclosed is a process for introducing a carboxyl group to an aromatic carboxylic acid or a derivative thereof, which comprises reacting a starting aromatic carboxylic acid, such as a benzoic acid, a biphenylcarboxylic acid, a naphthalenecarboxylic acid, a diphenylcarboxylic acid, or a derivative thereof, with a carbon tetrahalide in the presence of a cyclodextrin and an alkali metal hydroxide, thereby introducing a carboxyl group to the aromatic ring of the starting aromatic carboxylic acid or the derivative thereof in substitution for a hydrogen atom bonded thereto. By the process of the present invention, a desired aromatic polycarboxylic acid or a derivative thereof can be easily obtained with high selectivity.
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- Process for preparing aromatic polycarboxylic acids
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A process for preparing aromatic polycarboxylic acids is disclosed, wherein a benzil derivative is oxidized with molecular oxygen in the presence of an oxidation catalyst consisting substantially of at least one heavy metal catalyst selected from cobalt and manganese and a bromine catalyst in a solvent containing at least 50 wt.% of an aliphatic monocarboxylic acid having at most three carbon atoms. According to this invention, there are provided 4,4'-bis(4-alkylphenyl)benzils (wherein alkyl is methyl, ethyl or isopropyl), which are novel benzil derivative.
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- Preparation process of biphenyl-4,4'-dicarboxylic acid
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Biphenyl-4,4'-dicarboxylic acid is prepared by isolating a mixture of diisopropylbiphenyls from a reaction mixture obtained by reacting biphenyl with propylene, crystallizing 4,4'-diisopropylbiphenyl from the mixture of diisopropylbiphenyls, and oxidizing 4,4'-diisopropylbiphenyl or an oxidation intermediate thereof with molecular oxygen in the presence of an oxidation catalyst, which comprises a cobalt catalyst and/or manganese catalyst, in a solvent containing at least 50 wt. % of an aliphatic mono- carboxylic acid having up to 3 carbon atoms.
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- Polyaromatic compounds
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A halogen containing compound is coupled in the presence of carbon monoxide, an alkaline medium and a supported palladium catalyst. The reaction is preferably effected at elevated temperature and pressure, for example 80° C. to 200° C. and 0.2 to 3MNm-2. The alkaline medium can be aqueous sodium hydroxide solution. The support of the supported palladium catalyst may be calcium carbonate or charcoal. The halogen containing aromatic compound can be, for example, chlorobenzene; 4-chlorotoluene; 4-methoxychlorobenzene; 4-chlorophenol; 4-chlorobenzoic acid; 4-chloro-4'-hydroxybenzophenone; 4-bromobenzoic acid; 4-bromophenol; 2-chlorotoluene; 2-hydroxy-5-chlorobenzoic acid or 2-chloropyridine. Some of the resulting compounds or derivatives thereof are novel, such as 4,4'-bis(4-acetoxybenzoyl) biphenyl, which is useful as an intermediate for preparing polyesters and polyethers.
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- CATALYTIC REACTION OF SOME DERIVATIVES OF ACETYLENE WITH DIAZOTIZED AROMATIC DIAMINES
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The diazonium salts obtained from 4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-dimethoxybiphenyl, bis(4-aminophenyl) sulfone, and bis(4-aminophenyl) ether react with propargyl alcohol, propiolic acid, and phenylacetylene in the presence of cuprous chloride with release of the nitrogen of both diazo groups and form the bischloroarylation products.
- Ganushchak, N. I.,Prokopishin, I. Yu.,Zyubrik, A. I.,Kurik, M. V.,Fomenko, G. P.
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p. 2207 - 2210
(2007/10/02)
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