- Organocatalysis in cross-coupling: DMEDA-catalyzed direct C-H arylation of unactivated benzene
-
A striking breakthrough to the frame of traditional cross-couplings/C-H functionalizations using an organocatalyst remains unprecedented. We uncovered a conceptually different approach toward the biaryl syntheses by using DMEDA as the catalyst to promote the direct C-H arylation of unactivated benzene in the presence of potassium tert-butoxide. The arylation of unactivated benzene with aryl iodides, or aryl bromides and even chlorides under the assistance of an iodo-group, could simply take place at 80 °C. The new methodology presumably involves an aryl radical anion as an intermediate. This finding offers an option toward establishing a new horizon for direct C-H/cross-coupling reactions.
- Liu, Wei,Cao, Hao,Zhang, Hua,Zhang, Heng,Chung, Kin Ho,He, Chuan,Wang, Haibo,Kwong, Fuk Yee,Lei, Aiwen
-
-
Read Online
- G-C3N4/γ-Fe2O3/TiO2/Pd: A new magnetically separable photocatalyst for visible-light-driven fluoride-free Hiyama and Suzuki-Miyaura cross-coupling reactions at room temperature
-
In this paper, a new visible-light harvesting photocatalyst denoted as g-C3N4/γ-Fe2O3/TiO2/Pd was successfully fabricated and fully characterized by different techniques including FT-IR, XPS, XRD, TEM, SEM, elemental mapping, VSM, DRS, and ICP analysis. The as-prepared catalyst was utilized as an efficient magnetically separable photocatalyst in the fluoride-free Hiyama and Suzuki-Miyaura cross-coupling reactions at room temperature under visible light irradiation. By using this approach good to excellent yields of biaryls were achieved from the reaction of various aryl iodides/bromides and even chlorides as highly challenging substrates, which are more available and cheaper than aryl iodides and bromides, with triethoxyphenylsilane or phenylboronic acid. The superior photocatalytic activity of g-C3N4/γ-Fe2O3/TiO2/Pd could be attributed to the synergistic catalytic effects of Pd nanoparticles and g-C3N4/γ-Fe2O3/TiO2. Utilizing a sustainable and safe light source, no need to use any additive or heat, using an eco-friendly solvent and long-term stability and magnetic recyclability of the catalyst for at least seven successive runs are the advantages that support the current protocol towards green chemistry.
- Jahanshahi, Roya,Khazaee, Asma,Sobhani, Sara,Sansano, José Miguel
-
-
Read Online
- A novel three-step synthesis of N-(2-ethylhexyl)-2,7-diiodocarbazole
-
A new short and reasonably efficient synthesis of N-(2-ethylhexyl)-2,7- diiodocarbazole is presented. 4,4-Diiodobiphenyl was nitrated and the resulting 4,4-diiodo-2-nitrobiphenyl was converted via Freeman's modification of the Cadogan ring closure into 2,7-diiodocarbazole, which was then alkylated in the final step. The synthesis represents a significant simplification of the reported five-step procedure.
- Vyprachticky, Drahomir,Kminek, Ivan,Pavlakova, Petra,Cimrova, Vera
-
-
Read Online
- Dual gold photoredox C(sp2)-C(sp2) cross couplings-development and mechanistic studies
-
A dual visible light photoredox and gold-catalysed C(sp2)-C(sp2) cross coupling is described. The success of this mild, oxidant- and base-free cross coupling is highly dependent on the amount of water added. Mechanistic studies show two distinct pathways depending on the gold catalyst employed: transmetallation of the arylboronic acid with gold(i) occurs prior to oxidation of gold(i) to gold(iii) using cationic gold(i) catalysts, whereas oxidation of gold(i) to gold(iii) precedes transmetallation using neutral gold(i) catalysts.
- Gauchot, Vincent,Lee, Ai-Lan
-
-
Read Online
- Solid-phase iodination of arenes with the system iodine-diacetoxy(phenyl)- λ3-iodane
-
The system iodine-diacetoxy(phenyl)-λ3-iodane in the solid phase is capable of iodinating activated arenes.
- Krasnokutskaya,Trusova,Filimonov
-
-
Read Online
- Suzuki-Miyaura cross-coupling of arenediazonium salts with arylboronic acids catalyzed by a recyclable polymer-supported N-heterocyclic carbene-palladium catalyst
-
The Suzuki-Miyaura cross-coupling of arenediazonium salts with arylboronic acids catalyzed by a recyclable polymer-supported N-heterocyclic carbene-Pd complex catalyst has been achieved for the first time. The reaction was performed at room temperature under aerobic conditions to give biaryls in good to excellent yields in the absence of a base. The supported catalyst could be reused several times and still retained its high activity. Georg Thieme Verlag Stuttgart.
- Qin, Yuancheng,Wei, Wei,Luo, Meiming
-
-
Read Online
- Iodination and chlorination of aromatic polycyclic hydrocarbons with iodine monochloride in aqueous sulfuric acid
-
Polycyclic aromatic hydrocarbons when treated with iodine monochloride in water solutions of sulfuric acid afford iodo-and chloroderivatives. Biphenyl, fluorene, acenaphthene, 1-nitronaphthalene undergo iodination. Naphthalene furnishes a mixture of iodo-and chloroderivatives, prevailing the latter. Anthracene and phenanthrene provide only chlorinated products. The iodine monochloride in the sulfuric acid is a stronger iodinating agent than in acetonitrile.
- Chaikovskii,Filimonov
-
-
Read Online
- Halogen Exchange Between Aryl Grignarg Reagents and Aryl Halides in the Presence of Nickel(II) Chloride
-
A unique halogen exchange reaction between aryl Grignard reagents and aryl halides, which occured during an attempted cross-coupling reaction using non-ligated nickel(II) chloride as a catalyst, has been observed.The halogen exchange takes place between arylmagnesium iodides and aryl bromides but not between arylmagnesium bromides and aryl chlorides.
- Wang, Jiping,Pomerantz, Martin
-
-
Read Online
- Cross-coupling reactions of arenediazonium tetrafluoroborates with potassium aryl- or alkenyltrifluoroborates catalyzed by palladium
-
Potassium aryl- and alkenylflouroborates react smoothly with arenediazonium tetrafluoroborates under mild conditions in the presence of a palladium catalyst and without added base.
- Darses, Sylvain,Genet, Jean-Pierre,Brayer, Jean-Louis,Demoute, Jean-Pierre
-
-
Read Online
- Biaryl Coupling of Aryldiazonium Salts and Arylboronic Acids Catalysed by Gold
-
A gold-catalysed coupling of aryldiazonium salts with arylboronic acids is described. The reactions proceed in satisfactory yields under irradiation with blue LEDs in the presence of KF and a catalytic amount of ascorbic acid. Notably, 4-nitrobenzendiazonium tetrafluoroborate is sufficiently reactive to undergo the coupling with a variety of arylboronic acids in the absence of aryl radical initiators. The coupling is applicable for electron-donating and electron-withdrawing groups present at the para, ortho, and meta positions of both substrates.
- Medina-Mercado, Ignacio,Porcel, Susana
-
-
- Hydrogen-Bond-Donor Solvents Enable Catalyst-Free (Radio)-Halogenation and Deuteration of Organoborons
-
A hydrogen bond donor solvent assisted (radio)halogenation and deuteration of organoborons has been developed. The reactions exhibited high functional group tolerance and needed only an ambient atmosphere. Most importantly, compared to literature methods, our conditions are more consistent with the principals of green chemistry (e.g., metal-free, strong oxidant-free, more straightforward conditions).
- Yang, Yi,Gao, Xinyan,Zeng, Xiaojun,Han, Junbin,Xu, Bo
-
supporting information
p. 1297 - 1300
(2020/12/23)
-
- Fe-MIL-101 modified by isatin-Schiff-base-Co: a heterogeneous catalyst for C-C, C-O, C-N, and C-P cross coupling reactions
-
A metal-organic framework functionalized with a cobalt-complex is preparedviapost-synthetic modification of Fe-MIL-101-NH2. Initially, Fe-MIL-101-NH2reacted with isatin to produce Fe-MIL-101-isatin-Schiff-base, which can anchor the cobalt by the addition of cobalt acetate. The resulting MOF-Co catalyst is characterized by employing multiple techniques. This new modified MOF acts as a heterogeneous and recyclable catalyst for efficient Ullmann, Buchwald-Hartwig, Hirao, Hiyama and Mizoroki-Heck cross-coupling reactions of several aryl halides/phenylboronic acid/phenyltosylate with phenols, anilines/heterocyclic amines, triethyl phosphite, triethoxyphenylsilane and alkenes and generates the expected coupling products in good to high yields.
- Farrokhi, Alireza,Rouzifar, Majid,Sansano, José Miguel,Sobhani, Sara
-
p. 19963 - 19976
(2021/11/12)
-
- Water-Dispersible Pd–N-Heterocyclic Carbene Complex Immobilized on Magnetic Nanoparticles as a New Heterogeneous Catalyst for Fluoride-Free Hiyama, Suzuki–Miyaura and Cyanation Reactions in Aqueous Media
-
Abstract: Pd–N-heterocyclic carbine complex immobilized on magnetic nanoparticles is synthesized and characterized by different techniques such as FT-IR, XPS, TEM, EDX, FESEM, VSM, TGA, and ICP. The synthesized catalyst was used as a new water dispersible heterogeneous catalyst in the fluoride-free Hiyama, Suzuki–Miyaura and cyanation reactions in pure water. By this method, different types of biaryls and aryl nitriles were synthesized in good to high yields by the reaction of a variety of aryl iodides, bromides and chlorides with triethoxyphenylsilane, phenylboronic acid and K4[Fe(CN)6]·3H2O, respectively. The presence of sulfonates as hydrophilic groups on the surface of the catalyst confers a highly water dispersible, active and yet magnetically recoverable Pd catalyst. The possibility to perform the reaction in water as a green medium, ease of the catalyst recovery and reuse by magnetic separation, and the absence of any additives or co-solvents make this method as an eco-friendly and economical protocol for the synthesis of biaryl derivatives and aryl nitriles. Graphic Abstract: A new water dispersible heterogeneous Pd–N-heterocyclic carbene for the efficient fluoride-free Hiyama, Suzuki–Miyaura and cyanation reactions in pure water is developed.[Figure not available: see fulltext.].
- Chahkamali, Farhad Omarzehi,Sansano, José Miguel,Sobhani, Sara
-
-
- Synthesis of biaryl compounds via Suzuki homocoupling reactions catalyzed by metal organic frameworks encapsulated with palladium nanoparticles
-
Heterogeneous homocoupling reactions of phenylboronic acids were greatly accelerated via Suzuki homocoupling reactions. In this work, a tandem route was designed which firstly one part of phenylboronic acids reacted with iodine to form iodobenzenes, then another part of phenylboronic acids coupled with iodobenzenes to produce biaryl compounds. The tandem reaction were catalyzed by a bifunctional heterogeneous catalyst of metal organic frameworks encapsulated with palladium nanoparticles (Pd?MOFs). This strategy for forming symmetric C-C bond between benzene rings has obvious advantages such as high efficiency, easy separation, good recyclability and no addition of toxic halogenated benzene.
- Bao, Yan-Sai,Cui, Xin-Yu,Han, Zheng-Bo,Li, Xin,Tang, Hong,Yang, Ming,Zhang, Yu-Yang,Zhao, Kun,Zhou, Mei-Li
-
-
- Palladium-Catalyzed Decarbonylative Iodination of Aryl Carboxylic Acids Enabled by Ligand-Assisted Halide Exchange
-
We report an efficient and broadly applicable palladium-catalyzed iodination of inexpensive and abundant aryl and vinyl carboxylic acids via in situ activation to the acid chloride and formation of a phosphonium salt. The use of 1-iodobutane as iodide source in combination with a base and a deoxychlorinating reagent gives access to a wide range of aryl and vinyl iodides under Pd/Xantphos catalysis, including complex drug-like scaffolds. Stoichiometric experiments and kinetic analysis suggest a unique mechanism involving C?P reductive elimination to form the Xantphos phosphonium chloride, which subsequently initiates an unusual halogen exchange by outer sphere nucleophilic substitution.
- Boehm, Philip,Cacherat, Bastien,Lee, Yong Ho,Martini, Tristano,Morandi, Bill
-
supporting information
p. 17211 - 17217
(2021/07/02)
-
- Multifunctional Crown-5-calix[4]arene-based Phase-Transfer Catalysts for Aromatic 18F-Fluorination
-
Methylated bis-triethylene glycolic crown-5-calix[4]arene (M-BTC5A) as a phase-transfer catalyst showed the best performance among other analogues and even conventional Kryptofix 222 in the nucleophilic aromatic 18F-fluorination of diaryliodonium tosylate precursors owing to (i) the efficient release of reactive "naked"[18F]fluoride, (ii) the high stabilization of the precursor in the reaction, and, presumably, (iii) the ease of access between the precursor and the K18F/M-BTC5A complex facilitated by π-πinteractions. [18F]Flumazenil was produced in high radiochemical yield using M-BTC5A.
- Lee, Won Chang,Kang, Seok Min,Lee, Byung Chul,Kim, Sang Eun,Kim, Dong Wook
-
supporting information
p. 9551 - 9555
(2020/12/21)
-
- Arylation of aryllithiums with: S-arylphenothiazinium ions for biaryl synthesis
-
Aryllithiums are one of the most common and important aryl nucleophiles; nevertheless, methods for arylation of aryllithums to produce biaryls have been limited. Herein, we report arylation of aryllithiums with S-arylphenothiazinium ions through selective
- Morofuji, Tatsuya,Yoshida, Tatsuki,Tsutsumi, Ryosuke,Yamanaka, Masahiro,Kano, Naokazu
-
p. 13995 - 13998
(2020/11/21)
-
- NaH-mediated direct C-H arylation in the presence of 1,10-phenanthroline
-
Transition-metal-free coupling of haloarenes with unactivated arenes has been developed in the presence of NaH and 1,10-phenanthroline. Various haloarenes bearing methyl, methoxy, halogen (fluoride, chloride, and bromide), cyano, trifluoromethyl, ester, and amide groups can be cross-coupled with unactivated arenes, or heteroarenes in this reaction.
- Nozawa-Kumada, Kanako,Iwakawa, Yuki,Onuma, So,Shigeno, Masanori,Kondo, Yoshinori
-
supporting information
p. 7773 - 7776
(2020/07/27)
-
- A hydrophilic heterogeneous cobalt catalyst for fluoride-free Hiyama, Suzuki, Heck and Hirao cross-coupling reactions in water
-
A hydrophilic heterogeneous cobalt catalyst of chitosan, denoted as mTEG-CS-Co-Schiff-base, has been successfully prepared. This newly synthesized catalyst was characterized by different methods such as XRD, FE-SEM, TEM, TGA, FT-IR, 13C{1H} CP/MAS NMR, XPS and ICP analyses. The catalyst displayed excellent activity for the palladium and fluoride-free Hiyama, Suzuki, Heck and Hirao reactions of various aryl iodides, bromides and chlorides (i.e., the most challenging aryl halides which are cheaper and more widely available than aryl iodides and bromides) in water. The presence of triethylene glycol tags with hydrophilic character on the Co-complex supported on chitosan provides dispersion of the catalyst particles in water, which leads to higher catalytic performance and also facile catalyst recovery by successive extraction. It was reused for at least six successive runs without any discernible decrease in its catalytic activity or any remarkable changes in catalyst structure. The use of water as a green solvent, without requiring any additive or organic solvent, as well as use of a low cost and abundant cobalt catalyst instead of expensive Pd catalysts along with the catalyst recovery and scalability, make this method favorable from environmental and economic points of view for the C-C and C(sp2)-P coupling reactions. Notably, this is the first report on the application of a cobalt catalyst in Hiyama reactions.
- Sobhani, Sara,Hosseini Moghadam, Hadis,Skibsted, J?rgen,Sansano, José Miguel
-
p. 1353 - 1365
(2020/03/11)
-
- Generation of Organozinc Reagents by Nickel Diazadiene Complex Catalyzed Zinc Insertion into Aryl Sulfonates
-
The generation of arylzinc reagents (ArZnX) by direct insertion of zinc into the C?X bond of ArX electrophiles has typically been restricted to iodides and bromides. The insertions of zinc dust into the C?O bonds of various aryl sulfonates (tosylates, mesylates, triflates, sulfamates), or into the C?X bonds of other moderate electrophiles (X=Cl, SMe) are catalyzed by a simple NiCl2–1,4-diazadiene catalyst system, in which 1,4-diazadiene (DAD) stands for diacetyl diimines, phenanthroline, bipyridine and related ligands. Catalytic zincation in DMF or NMP solution at room temperature now provides arylzinc sulfonates, which undergo typical catalytic cross-coupling or electrophilic substitution reactions.
- Klein, Philippe,Lechner, Vivien Denise,Schimmel, Tanja,Hintermann, Lukas
-
p. 176 - 180
(2019/12/11)
-
- Synthesis method of 4-iodobiphenyl
-
The invention discloses a synthesis method of 4-iodobiphenyl. According to the method, based on the Suzuki coupling reaction, 1,4-diiodobenzene and phenylboronic acid are taken as raw materials, wateris taken as a solvent, a reaction is carried out for 4-12 h at 50-100 DEG C under the catalysis of Pd/C, and post-treatment of a reaction product is conducted to obtain the target product 4-iodobiphenyl. Water is used as a reaction solvent, the catalyst can be recycled, and the method is high in yield, free of pollution, simple in process, convenient to operate and beneficial for industrial production, and meets environmental protection requirements.
- -
-
Paragraph 0010-0014
(2020/08/30)
-
- 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)
-
- Willgerodt-Type Dichloro(aryl)-λ 3-Iodanes: A Structural Study
-
Crystallographic structural analysis of four electronically diverse Willgerodt-type reagents is disclosed together with a solution-phase NMR analysis. These data reveal a plethora of intermolecular non-covalent interactions and confirm the expected T-shape geometry of the reagents. In all cases the I-Cl bonds are orthogonal to the plane of the aryl ring. This study provides important structural insights into this venerable class of dichlorination reagent and has implications for crystal engineering.
- Daniliuc, Constantin G.,Gilmour, Ryan,Neufeld, Jessica,Sarie, Jér?me C.
-
p. 4408 - 4416
(2019/11/21)
-
- PdO nanoparticles supported on triazole functionalized porous triazine polymer as an efficient heterogeneous catalyst for carbonylation of aryl halides
-
A well-defined triazole functionalized porous triazine based polymers act as solid heterogeneous catalyst after incorporating palladium oxide nanoparticles (PdO@TTAS) have been synthesized and thoroughly characterized by various techniques such as, FT-IR, UV-DRS, solid state 13C CP-MAS, XPS, powder X-ray diffraction, TGA, SEM and TEM analysis has been detailed illustrated. It is important to note that synthesized catalytic performance for carbonylation of aryl halides (X?=?I, Br) with EDC.HCl (N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride), and formic acid was found to be an effective CO source in the presence of triethylamine as a base and DMF as a solvent medium at 80?°C for about 3?hr. The PdO@TTAS catalyst exhibits superior catalytic performance and along with good yield (up to 90%). Moreover, studying the heterogeneity and reusability of the environmentally friendly solid catalyst can be easily separated by simple filtration and then recycled for several times. In this reaction method, we avoided ligand, additive, promoters and CO gas, due to additional problem arise by using gaseous CO, highly toxic greenhouse gases and high pressurized reaction setup.
- Sadhasivam, Velu,Balasaravanan, Rajendran,Siva, Ayyanar
-
supporting information
(2019/07/03)
-
- Copper(I)-promoted trifluoromethylthiolation of arenediazonium salts with AgSCF3
-
An efficient method for trifluoromethylthiolation of arenediazonium salts has been developed in mild conditions with a stable and convenient AgSCF3. It provides a straightforward and convenient way for the synthesis of trifluoromethylthiolated compound from diazonium salts in moderate to good yields.
- Zheng, Changge,Liu, Yang,Hong, Jianquan,Huang, Shuai,Zhang, Wei,Yang, Yupeng,Fang, Ge
-
p. 1404 - 1407
(2019/05/01)
-
- Base-Mediated Defluorosilylation of C(sp2)?F and C(sp3)?F Bonds
-
The ability to selectively forge C–heteroatom bonds by C?F scission is typically accomplished by metal catalysts, specialized ligands and/or harsh reaction conditions. Described herein is a base-mediated defluorosilylation of unactivated C(sp2)?F and C(sp3)?F bonds that obviates the need for metal catalysts. This protocol is characterized by its simplicity, mild reaction conditions, and wide scope, even within the context of late-stage functionalization, constituting a complementary approach to existing C?Si bond-forming protocols.
- Liu, Xiang-Wei,Zarate, Cayetana,Martin, Ruben
-
p. 2064 - 2068
(2019/01/25)
-
- Synthesis, structure, and synthetic potential of arenediazonium trifluoromethanesulfonates as stable and safe diazonium salts
-
Aromatic diazonium salts are valuable building blocks for organic synthesis; however, in most cases, they are unstable, unsafe, poorly soluble, and/or expensive. In this paper, we have shown that a variety of stable and safe arenediazonium triflates ArN2+ TfO– can be obtained easily and in high yields by diazotization of anilines with tert-butyl nitrite in the presence of trifluoromethanesulfonic acid. Arenediazonium triflates are relatively shelf-stable in the dry state. They dissolve well in water, as well as polar and even nonpolar organic solvents. Less than 800 J/g of energy is released during the thermal decomposition of these salts, which indicates their explosion safety. Arenediazonium triflates have a high reactivity in the known reactions of diazonium chemistry, and undergo an unusual metal-free chlorodediazonization reaction with chloroform and CCl4.
- Filimonov, Victor D.,Krasnokutskaya, Elena A.,Kassanova, Assia Zh.,Fedorova, Valentina A.,Stankevich, Ksenia S.,Naumov, Nikolay G.,Bondarev, Alexander A.,Kataeva, Veronika A.
-
supporting information
p. 665 - 674
(2018/09/14)
-
- ipso-Bromination/iodination of arylboronic acids: Poly(4-vinylpyridine)-Br2/I2 complexes as safe and efficient reagents
-
Poly(4-vinyl pyridine) supported bromine/iodine complexes were prepared and probed for ipso-bromination/iodination of arylboronic acids. These solid complexes with catalytic amount of additive are found to be safe and efficient reagent system for the ipso-bromination/iodination. The reaction occurs under mild conditions and tolerates various functional groups resulting in products with high selectivity and yields.
- Fu, Fang,Gurung, Laxman,Czaun, Miklos,Mathew, Thomas,Prakash, G.K. Surya
-
supporting information
(2019/08/26)
-
- Mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen: Development of a base-catalyzed iododeboronation for radiolabeling applications
-
An investigation into the mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen reagents is reported. Evidence is provided to show that this takes place via a boronate-driven ipso-substitution pathway and that Cu is not required for these processes to operate: General Lewis base catalysis is operational. This in turn allows the rational development of a general, simple, and effective base-catalyzed halodeboronation that is amenable to the preparation of 125I-labeled products for SPECT applications.
- Molloy, John J.,O'rourke, Kerry M.,Frias, Carolina P.,Sloan, Nikki L.,West, Matthew J.,Pimlott, Sally L.,Sutherland, Andrew,Watson, Allan J. B.
-
supporting information
p. 2488 - 2492
(2019/04/10)
-
- Base-free Pd-MOF catalyzed the Suzuki-Miyaura cross-coupling reaction of arenediazonium tetrafluoroborate salts with arylboronic acids
-
A convenient and environmental benign synthesis of biaryls has been demonstrated by a straightforward reaction catalyzed by the palladium-containing metal-organic framework (Pd-MOF) [Pd (2-pymo)2]n (2-pymo = 2-pyrimidinolate). A series of functionalized biaryl derivatives have been synthesized in good to excellent yields by the Suzuki-miyaura cross-couplings of sustainable arenediazonium salts with a variety of arylboronic acids and the reactions were catalyzed by the Pd-MOF using methanol as a benign solvent. Those base- and additive-free catalytic reactions proceeded smoothly under non-anhydrous and non-degassed condition. Such transformation avoided high reaction temperature, tolerated many functional groups and presented a wide substrate scope. The catalyst could be recovered by filtration and reused for four successive cycles before collapse of the MOF structure.
- Liu, Yangyang,Wang, Jie,Li, Tang,Zhao, Zesheng,Pang, Wan
-
-
- Metal-Free and Redox-Neutral Conversion of Organotrifluoroborates into Radicals Enabled by Visible Light
-
Converting organoboron compounds into the corresponding radicals has broad synthetic applications in organic chemistry. To achieve these transformations, various strong oxidants such as Mn(OAc)3, AgNO3/K2S2O8, and Cu(OAc)2, in stoichiometric amounts are required, proceeding by a single-electron transfer mechanism. Established herein is a distinct strategy for generating both aryl and alkyl radicals from organotrifluoroborates through an SH2 process. This strategy is enabled by using water as the solvent, visible light as the energy input, and diacetyl as the promoter in the absence of any metal catalyst or redox reagent, thereby eliminating metal waste. To demonstrate its synthetic utility, an efficient acetylation to prepare valuable aryl (alkyl) methyl ketones is described and applications to construct C?C, C?I, C?Br, and C?S bonds are also feasible. Experimental evidence suggests that triplet diacetyl serves as the key intermediate in this process.
- Liu, Wenbo,Liu, Peng,Lv, Leiyang,Li, Chao-Jun
-
supporting information
p. 13499 - 13503
(2018/09/25)
-
- Gold catalysed Suzuki-Miyaura coupling of arenediazonium o-benzenedisulfonimides
-
Arenediazonium o-benzenedisulfonimides have been used as efficient electrophilic partners in Au(I) catalysed Suzuki coupling reactions. The synthetic protocol is general, easy and produced either biaryls or heteroaryl arenes in good yields (51 positive examples, average yield 80%). o-Benzenedisulfonimide was recovered at the end of the reactions and was reused to prepare the starting salts for further reactions. Mechanistic insights suggest that the o-benzenedisulfonimide anion act as an electron transfer agent and promotes a catalytic cycle which does not require the presence of photocatalysts or external oxidants.
- Barbero, Margherita,Dughera, Stefano
-
p. 5758 - 5769
(2018/09/10)
-
- GOLD-CATALYZED C-C CROSS-COUPLING OF BORON- AND SILICON-CONTAINING ARYL COMPOUNDS AND ARYLDIAZONIUM COMPOUNDS BY VISIBLE-LIGHT
-
The present invention relates to a method for producing (functionalized) biaryls by employing a visible-light-driven, gold-catalyzed C-C cross-coupling reaction system involving boron- and silicon-containing aryl compounds and aryldiazonium compounds. Moreover, the present invention relates to the use of such boron- and silicon-containing aryl compounds and aryldiazonium compounds, as well as related gold catalysts, in the manufacture of (functionalized) biaryls.
- -
-
Page/Page column 24; 25; 42
(2018/07/29)
-
- Synthesis of Bi(hetero)aryls via Sequential Oxidation and Decarboxylation of Benzylamines in a Batch/Fully Automated Continuous Flow Process
-
Catalytic dehydrogenative cross-coupling of two C–H bonds represents a green strategy in view of the atom- and step-economy. However, the challenge is to discover a new innovative bond strategy, especially for the direct coupling between Csp2–H
- Mahajan, Bhushan,Aand, Dnyaneshwar,Singh, Ajay K.
-
supporting information
p. 2831 - 2835
(2018/06/21)
-
- Direct Aryl-Aryl Coupling without Pre-Functionalization Enabled by Excessive Oxidation of Two-Electron Ag(I)/Ag(III) Catalyst
-
Reported herein is a catalytic platform for formation of unsymmetrical biaryls by the coupling between inert Csp2?CH3 and Csp2?H via a tandem catalytic strategy. The platform utilizes traditional AgNO3 catalyst and excess amount of K2S2O8 oxidant. The excessive oxidant present converts the traditional one-electron Ag(I)/Ag(II) chemistry to two-electron Ag(I)/Ag(III) one, enabling one-pot synthesis of aryl-aryl scaffolds by using unactivated cheap commodity chemicals. (Figure presented.).
- Singh, Ajay K.,Kim, Min-Gyu,Lee, Hyune-Jea,Singh, Rakhi,Cho, Seung Hwan,Kim, Dong-Pyo
-
supporting information
p. 2032 - 2042
(2018/04/11)
-
- Denitrogenative Pd/Cu-catalyzed Suzuki-type Cross-coupling of Aryltrifluoroborates with Arylhydrazine Hydrochlorides in Water under Room Temperature
-
A water-soluble palladium-catalyzed Suzuki-type cross-coupling of aryltrifluoroborates with arylhydrazide hydrochlorides was efficiently developed under mild and environmentally benign conditions, in water without any ligand. The newly developed Pd/Cu co-catalyzed denitrogenative reaction gave a range of structurally diverse substituted biaryls with good to excellent yields, in which the byproduct was nitrogen.
- Wang, Guofang,Meng, Mengting,Deng, Liping,Cheng, Kai,Qi, Chenze
-
-
- Electrochemical Synthesis of Aryl Iodides by Anodic Iododesilylation
-
An electrochemical access to iodinated aromatic compounds starting from trimethylsilyl-substituted arenes is presented. By design of experiments, highly efficient and mild conditions were identified for a wide range of substrates. A functional group stability test and the synthesis of an important 3-iodobenzylguanidine radiotracer illustrate the scope of this process.
- M?ckel, Robert,Hille, Jessica,Winterling, Erik,Weidemüller, Stephan,Faber, Tabea Melanie,Hilt, Gerhard
-
supporting information
p. 442 - 445
(2018/02/21)
-
- Efficient Suzuki-Miyaura mono-arylation of symmetrical diiodo(hetero)arenes
-
A reliable protocol for converting 1,4-diiodo-2,3,5,6-tetrafluorobenzene into 1-(hetero)aryl-4-iodo-2,3,5,6-tetrafluorobenzene derivatives has been lacking in the literature. We have identified optimal conditions to achieve this conversion in good yields and have minimized formation of the bis-coupling product. The newly identified protocol involving the use of a syringe pump has been extended to other symmetrical diiodo(hetero)arenes.
- Sapegin, Alexander,Krasavin, Mikhail
-
supporting information
p. 1948 - 1951
(2018/04/16)
-
- Copper-catalysed aromatic-Finkelstein reactions with amine-based ligand systems
-
A new efficient and low-cost ligand, diethylenetriamine, has been utilised to promote the iodination of 16 different bromo-substrates via the copper catalysed Finkelstein halogen exchange reaction under mild conditions. In contrast to earlier methods, the use of inert atmosphere conditions was not required to obtain high yields and purity. Studies on the speciation of the catalyst in solution indicate rapid disproportionation of copper(i) in the presence of diethylenetriamine to give copper(0) and a bis-ligated copper(ii) complex which is characterised by X-ray diffraction. This copper(ii) complex was also shown to be catalytically active in the halogen exchange reaction. In contrast, no significant disproportionation was observed using dimethylethylenediamine as the ligand, and the solid-state structures of a copper(i) dimeric complex and a 2D polymeric network of copper(i) iodide tetramers are reported. The catalytic activity of diethylenetriamine and dimethylethylenediamine with both copper(i) and copper(ii) salts are compared, and possible mechanistic implications discussed.
- Jin, Xiaodong,Davies, Robert P.
-
p. 2110 - 2117
(2017/07/22)
-
- Oriented Au nanoplatelets on graphene promote Suzuki-Miyaura coupling with higher efficiency and different reactivity pattern than supported palladium
-
Facet 1?1?1 oriented Au nanoplatelets (20–40?nm wide, 3–4?nm height) grafted on graphene (Au ̄/fl-G) are about three orders of magnitude more efficient than Pd nanoparticles supported on graphene to promote Suzuki-Miyaura coupling. In contrast to Pd cataly
- Candu, Natalia,Dhakshinamoorthy, Amarajothi,Apostol, Nicoleta,Teodorescu, Cristian,Corma, Avelino,Garcia, Hermenegildo,Parvulescu, Vasile I.
-
-
- Direct arylation of inactivated benzene with aryl acyl peroxides toward biaryls
-
A direct arylation of inactivated benzene with acyl peroxides was developed, affording biaryls in good to excellent yields. This transformation underwent a radical pathway under metal-free, base-free and additive-free conditions with good functional group compatibility.
- Pan, Changduo,Zhu, Jiawei,Chen, Rongzhen,Yu, Jin-Tao
-
supporting information
p. 6467 - 6469
(2017/08/16)
-
- Simple and Efficient Generation of Aryl Radicals from Aryl Triflates: Synthesis of Aryl Boronates and Aryl Iodides at Room Temperature
-
Despite the wide use of aryl radicals in organic synthesis, current methods to prepare them from aryl halides, carboxylic acids, boronic acids, and diazonium salts suffer from limitations. Aryl triflates, easily obtained from phenols, are promising aryl radical progenitors but remain elusive in this regard. Inspired by the single electron transfer process for aryl halides to access aryl radicals, we developed a simple and efficient protocol to convert aryl triflates to aryl radicals. Our success lies in exploiting sodium iodide as the soft electron donor assisted by light. This strategy enables the scalable synthesis of two types of important organic molecules, i.e., aryl boronates and aryl iodides, in good to high yields, with broad functional group compatibility in a transition-metal-free manner at room temperature. This protocol is anticipated to find potential applications in other aryl-radical-involved reactions by using aryl triflates as aryl radical precursors.
- Liu, Wenbo,Yang, Xiaobo,Gao, Yang,Li, Chao-Jun
-
supporting information
p. 8621 - 8627
(2017/07/06)
-
- A Sustainable Heterogeneous Iron Catalyst Fe/SBA-15 towards Direct Arylation of Unactivated C(sp3)?H and C(sp2)?H Bonds with Arenes
-
Iron grafted over mesoporous silica (8 wt %Fe/SBA-15) is a sustainable, efficient heterogeneous iron catalyst for direct arylation of biphenyl methane C(sp3)?H and benzene C(sp2)?H bonds. The selective extraction deposition (SED) technique was adopted to graft iron easily over the mesoporous support SBA-15 by using LaFeO3 as an iron precursor. The synthesized catalyst has been characterized by EPR spectroscopy, diffuse reflectance UV/Vis spectroscopy, and temperature programmed reduction (TPR) analysis to understand the coordination environment and state of oxidic iron species grafted over the mesoporous SBA-15. TPR results confirm the presence of isolated, clustered, oligomeric oxidic iron species in the catalyst. The adopted SED technique is highly successful for grafting 8 wt % iron into the mesopores of SBA-15 without forming iron oxide particles. Unlike homogeneous iron, the 8 wt %Fe/SBA-15 catalyst does not need support from an electron-withdrawing group and additives to carry out arylation of benzene and could be successfully recycled five times.
- Rajendran,Satishkumar
-
p. 1284 - 1291
(2017/04/14)
-
- Arylation of hydrocarbons enabled by organosilicon reagents and weakly coordinating anions
-
Over the past 80 years, phenyl cation intermediates have been implicated in a variety of C-H arylation reactions. Although these examples have inspired several theoretical and mechanistic studies, aryl cation equivalents have received limited attention in organic methodology. Their high-energy, promiscuous reactivity profiles have hampered applications in selective intermolecular processes. We report a reaction design that overcomes these challenges. Specifically, we found that b-silicon-stabilized aryl cation equivalents, generated via silylium-mediated fluoride activation, undergo insertion into sp3 and sp2 C-H bonds. This reaction manifold provides a framework for the catalytic arylation of hydrocarbons, including simple alkanes such as methane. This process uses low loadings of Earth-abundant initiators (1 to 5 mole percent) and occurs under mild conditions (30° to 100°C).
- Shao, Brian,Bagdasarian, Alex L.,Popov, Stasik,Nelson, Hosea M.
-
-
- Photosensitizer-Free, Gold-Catalyzed C–C Cross-Coupling of Boronic Acids and Diazonium Salts Enabled by Visible Light
-
The first photosensitizer-free visible light-driven, gold-catalyzed C–C cross-couplings of arylboronic acids and aryldiazonium salts are reported. The reactions can be conducted under very mild conditions, using a catalytic amount of tris(4-trifluoromethyl)phosphinegold(I) chloride [(4-CF3-C6H4)3PAuCl] with methanol as the solvent allowing an alternative access to a variety of substituted biaryls in moderate to excellent yields with broad functional group tolerance. (Figure presented.).
- Witzel, Sina,Xie, Jin,Rudolph, Matthias,Hashmi, A. Stephen K.
-
supporting information
p. 1522 - 1528
(2017/05/05)
-
- ONE STEP DIRECT ARYLATION OF COMMODITY CHEMICALS TO SPECIALTY CHEMICALS BY TANDEM CATALYTIC PLATFORM
-
The present invention relates to a continuous direct arylation process based on a tandem catalyst for synthesizing specialty chemicals. A method for synthesizing an aryl-aryl structure from a substrate selected from the group consisting of benzyl alcohol, benzyl amine and toluene which are low value added compounds is developed using a silver ion-containing tandem catalyst. The method is applied for synthesizing hexaphenyl arylene and can be applied for synthesizing high value added compounds (not only natural substances and chemical compounds but pharmaceutical and agricultural pesticide relative fields) directly from primary raw materials through the reaction.COPYRIGHT KIPO 2017
- -
-
Paragraph 0057; 0058; 0066-0103; 0106
(2018/02/28)
-
- Copper-Mediated Functionalization of Aryl Trifluoroborates
-
This paper describes the Cu(OTf)2-mediated coupling of aryl and heteroaryl trifluoroborates with tetrabutylammonium or alkali metal salts to form C-O, C-N, and C-halogen bonds. The reactions proceed under mild conditions (often room temperature over 16 hours) with carboxylate, halide, and azide salts, all nucleophiles that have been underrepresented in the copper cross-coupling literature. Preliminary results show that copper salts bearing weakly coordinating X-type ligands are essential for enabling these transformations to proceed under mild conditions.
- Schimler, Sydonie D.,Sanford, Melanie S.
-
supporting information
p. 2279 - 2284
(2016/10/06)
-
- Ligand- and Base-Free Access to Diverse Biaryls by the Reductive Coupling of Diaryliodonium Salts
-
A ligand- and base-free, Pd-catalyzed protocol to access a wide range of symmetrical and unsymmetrical biaryls from stable diaryliodonium salts was developed. The reaction involved the use of an effective and recyclable Pd/polyethylene glycol-400 catalyst system to harness the aryl moieties of two diaryliodonium salts; the ensuing biaryls may be utilized to synthesize an array of useful compounds, including 5-aryluracils, carbazoles, chromenones, fluorenones, phenathridines, and boscalid analogues.
- Arun,Reddy, P. O. Venkataramana,Pilania, Meenakshi,Kumar, Dalip
-
supporting information
p. 2096 - 2100
(2016/05/09)
-
- Desulfonative pd-catalyzed coupling of aryl trifluoroborates with arylsulfonyl chlorides
-
A Pd-catalyzed cross-coupling of aryl trifluoroborates with arylsulfonyl chlorides has been successfully achieved. This transformation is a new method for the Suzuki–Miyaura-type reaction of aryl trifluoroborates via the cleavage of C? S bond, thus providing an alternative synthesis of biaryls. The reported cross-coupling reactions are tolerant to many common functional groups regardless of electron-donating or electron-withdrawing nature, making these transformations attractive alternatives to the traditional Suzuki–Miyaura coupling approaches. Copyright
- Wei, Zhen,Xue, Dazhong,Zhang, Haisheng,Guan, Jinyu
-
p. 767 - 771
(2016/09/04)
-
- One-Step Pyrolysis Preparation of 1.1.1 Oriented Gold Nanoplatelets Supported on Graphene and Six Orders of Magnitude Enhancement of the Resulting Catalytic Activity
-
Pyrolysis of chitosan films containing Au3+ renders 1.1.1 oriented Au nanoplatelets (20 nm lateral size, 3-4 nm height) on a few layers of N-doped graphene (${overline {{rm{Au}}} }$/fl-G), while the lateral sides were 0.0.1 oriented. Comparison of the catalytic activity of ${overline {{rm{Au}}} }$/fl-G films with powders of unoriented Au NPs supported on graphene showed that ${overline {{rm{Au}}} }$/fl-G films exhibit six orders of magnitude enhancement for three gold-catalyzed reactions, namely, Ullmann-like homocoupling, C-N cross coupling, and the oxidative coupling of benzene to benzoic acid. This enhancement is the result of the defined morphology, facet orientation of Au nanocrystals, and strong gold-graphene interaction.
- Primo, Ana,Esteve-Adell, Ivan,Coman, Simona N.,Candu, Natalia,Parvulescu, Vasile I.,Garcia, Hermenegildo
-
p. 607 - 612
(2016/02/27)
-
- Copper-mediated aerobic iodination and perfluoroalkylation of boronic acids with (CF3)2CFI at room temperature
-
The copper-mediated aerobic reactions between the branched (CF3)2CFI and boronic acids (R-B(OH)2) are described. Different from the linear perfluoroalkyl analogs CF3(CF2)nI (n?=?2, 3, 5, 7), (CF3)2CFI reacting with R-B(OH)2at room temperature under air in the presence of catalytic Cu powder provided exclusively the corresponding iodides (R-I), while the aerobic reactions of arylboronic acids with (CF3)2CFI at room temperature in the presence of Cu(OAc)2gave the perfluoroalkylation products (R-CF(CF3)2) in acceptable to moderate yields. The iodination reaction could be further promoted by hydroquinone, the addition of which improved the oxidation ability of (CF3)2CFI and provided the ipso-iodination products in high yields. The perfluoroalkylation was facilitated by the copper carboxylates since the addition of these salts into the reaction mixtures could successfully give rise to Ar-CF(CF3)2.
- Liu, Xi-Hai,Leng, Jing,Jia, Su-Jiao,Hao, Jian-Hong,Zhang, Fanglin,Qin, Hua-Li,Zhang, Cheng-Pan
-
-
- Gold-catalysed cross-coupling between aryldiazonium salts and arylboronic acids: Probing the usefulness of photoredox conditions
-
The synthesis of biaryl compounds from aryldiazonium salts and arylboronic acids was achieved using PPh3AuCl as catalyst, CsF as base and acetonitrile as solvent. Combined to photosensitizers, irradiation by blue LEDs allowed accelerating the reaction and expanding its scope. Various functional groups were compatible including bromoaryls, iodoaryls, aldehydes and alcohols. A 2-iodobenzyl alcohol moiety was smoothly introduced by this method, enabling its consecutive isotopic labelling by a Pd-catalysed alkoxycarbonylation.
- Cornilleau, Thomas,Hermange, Philippe,Fouquet, Eric
-
p. 10040 - 10043
(2016/08/15)
-
- Polystyrene-resin supported N-heterocyclic carbene-Pd(II) complex based on plant-derived theophylline: A reusable and effective catalyst for the Suzuki-Miyaura cross-coupling reaction of arenediazonium tetrafluoroborate salts with arylboronic acids
-
Polystyrene-supported NHC-Pd(II) complex based on theophylline as a sustainable NHC precursor was employed in the Suzuki-Miyaura cross-coupling reaction of substituted arenediazonium tetrafluoroborate salts with a variety of arylboronic acids to afford functionalized biaryl derivatives in good to excellent yields without using base or additive as promoters. The catalyst was easily recovered by ?ltration and reused for six successive cycles.
- Mohammadi, Elmira,Movassagh, Barahman
-
-
- Easy Access to Difluoromethylene-Containing Arene Analogues through Palladium-Catalysed C–H Olefination
-
An efficient palladium-catalysed ortho-C–H olefination of α,α-difluorophenylacetic acid derivatives using 8-aminoquinoline as a bidentate directing group has been developed. A range of olefinated arenes can thus be synthesized in a concise way. This reaction provides an easy and straightforward route to a panel of difluoromethylated arene analogues in moderate to good yields, with a satisfactory tolerance of common functional groups. Transformation of the products into a variety of other difluoromethylene-containing compounds demonstrates the utility of this method.
- Shao, Changdong,Shi, Guangfa,Zhang, Yanghui
-
supporting information
p. 5529 - 5538
(2016/11/25)
-
- Palladium-catalyzed denitrogenative Hiyama cross-coupling with arylhydrazines under air
-
A Pd-catalyzed denitrogenative Hiyama coupling of arylhydrazines and aryl silanes is described under mild conditions. The newly developed catalytic system does not require the use of expensive silver- or copper-based stoichiometric oxidants to obtain diaryl derivatives with high selectivity and reactivity. The reported coupling reactions are very practical as they do not require the protection of inert gas or oxygen and are tolerant to many functional groups.
- Zhang, Hui,Wang, Chunjie,Li, Zhiwei,Wang, Ziyun
-
supporting information
p. 5371 - 5376
(2015/09/15)
-
- 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
-
p. 27029 - 27033
(2015/03/30)
-
- Practical and efficient ipso-iodination of arylboronic acids via KF/I2 system
-
A facile and effective iododeboronation of variously substituted aryl and heteroarylboronic acids through activation and subsequent ipso-introduction of iodine is presented. The use of KF and I2 at 80 °C in 1,4-dioxane furnishes iodinated compounds in high yields.
- Tramutola, Francesco,Chiummiento, Lucia,Funicello, Maria,Lupattelli, Paolo
-
p. 1122 - 1123
(2015/02/19)
-