- 3,3'-((Arylmethylene)bis(4-methoxy-3,1-phenylene)) dipyridine derivatives as convenient ligands for Suzuki–Miyaura chemo- and homoselective cross-coupling reactions
-
Four novel N,N-bidentate triarylmethane-based ligands bearing β-pyridyl residues have been prepared and the catalytic activity of their in-situ generated palladium complexes were studied in the Suzuki–Miyaura cross-coupling reactions. Air and moisture stable 3,3'-((arylmethylene)bis(4-methoxy-3,1-phenylene))dipyridines L1-3 showed excellent activity in the Suzuki coupling reactions of aryl halides with aryl boronic acids under thermal and sonochemical reaction conditions. The described methodology provided good to high yields in short reaction times at ambient conditions. Moreover, it offered a straightforward way for Suzuki–Miyaura chemo- and homoselective cross-coupling of aryl halides with phenyl boronic acid. The structures of synthesized compounds were fully characterized by FT-IR, 1H-NMR, 13C-NMR, and elemental analyses. The coordination of palladium acetate to nitrogen sites of L1 was also studied using FTIR spectroscopy, EDX analysis and SEM observations. Graphic abstract: The in-situ generated Pd-complexes of N,N-bidentate ligands L1-3 are described as robust and highly effective catalytic systems for the Suzuki cross-coupling of aryl halides with aryl boronic acids under thermal and sonochemical reaction conditions.[Figure not available: see fulltext.]
- Hosseini, Raziyeh,Mohammadiannejad, Kazem,Ranjbar-Karimi, Reza
-
-
- 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)
-
- Anthracene-containing dimer skeleton ligand and preparation method thereof, and application in metal catalytic reaction
-
The invention provides an anthracene dimer derivative phosphine-containing ligand as shown in the following formula I, wherein the anthracene dimer derivative phosphine-containing ligand can be used for a series of transition metal catalyzed coupling reac
- -
-
Paragraph 0143-0146
(2021/01/29)
-
- Direct C-H photoarylation of diazines using aryldiazonium salts and visible-light
-
In this study, direct C-H photoarylation of pyrazine with aryldiazonium salts under visible-light irradiation (blue-LEDs) is described, and additional examples including photoarylations of pyrimidine and pyridazine are also covered. The corresponding aryl-diazines were prepared in yields up to 84% only by mixing and irradiating the reaction with no need for an additional photocatalyst. We demonstrate the efficacy of this protocol by the scope with electron-donor, -neutral, and -withdrawing groups attached at the ortho, meta, and para positions of the aryldiazonium salts; the results are better than those reported for ruthenium-complex mediated photoarylations. Additionally, we demonstrate the robustness of this methodology with a 5 mmol scaled-up experiment. Mechanistic studies were carried out giving support to the proposal of a photocatalyzed approach by an electron donor-acceptor (EDA) complex, also highlighting the crucial role that solvents play in the formation of the EDA complex. This journal is
- Silva, Rodrigo C.,Villela, Lucas F.,Brocksom, Timothy J.,De Oliveira, Kleber T.
-
p. 31115 - 31122
(2020/09/23)
-
- 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)
-
- 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)
-
- Synthesis of Enaminone-Pd(II) Complexes and Their Application in Catalysing Aqueous Suzuki-Miyaura Cross Coupling Reaction
-
A series of Pd(II)-enaminone complexes, termed Pd(eao)2, have been synthesized and characterized. The investigation on the catalytic activities of these new Pd(II)-reagents has proved that the Pd(eao)2-1 possesses excellent catalytic activity for the Suzuki- Miyaura cross coupling reactions of aryl bromides/chlorides with aryl/vinyl boronic acids in the environmentally benign media of aqueous PEG400 at low loading (5 mol‰). The superiority of this Pd(II)-reagent to those commercial Pd(II) and Pd(0) catalysts in catalyzing the reactions has been confirmed by parallel experiments. What's more, Pd(eao)2-2 has been found as a practical catalyst for the homo-coupling reactions of aryl boronic acids.
- Fu, Leiqing,Cao, Xiaoji,Wan, Jie-Ping,Liu, Yunyun
-
p. 254 - 258
(2020/01/25)
-
- Au(I)-Catalyzed Hydration of 1-Iodoalkynes Leading to α-Iodoketones
-
A catalytic protocol for the Au(I)-catalyzed hydration of 1-iodoalkynes is disclosed. The use of Au(I)–NHC catalyst enabled the straightforward synthesis of a variety of α-iodomethyl ketones in good to excellent yields. The utility of this simple method is further highlighted by showcasing iodination/hydration and hydration/oxidation sequential protocols leading to the construction of molecular complexity.
- Cazin, Catherine S. J.,Gómez-Herrera, Alberto,Hashim, Ishfaq Ibni,Nahra, Fady,Porré, Marre
-
p. 6790 - 6794
(2020/11/23)
-
- 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)
-
- A Monophosphine Ligand Derived from Anthracene Photodimer: Synthetic Applications for Palladium-Catalyzed Coupling Reactions
-
Herein, we present an air-stable dianthracenyl monophosphine ligand (diAnthPhos) which can be prepared in two steps from commercially available anthracene derivatives. The ligand exhibits excellent efficiency for palladium-catalyzed coupling reactions. In particular, Miyaura borylation of heterocycle-containing electrophiles can be facilitated employing the diAnthPhos ligand with a broad substrate scope and low catalyst loading. The valuable synthetic utility of the new ligand is further demonstrated by a one-pot Miyaura borylation/Suzuki coupling protocol for heteroaryl-containing substrates.
- Wang, Xin,Liu, Wei-Gang,Tung, Chen-Ho,Wu, Li-Zhu,Cong, Huan
-
supporting information
p. 8158 - 8163
(2019/09/07)
-
- Electrochemical oxidation synergizing with Br?nsted-acid catalysis leads to [4 + 2] annulation for the synthesis of pyrazines
-
An electrochemical dehydrogenative [4 + 2] annulation for the synthesis of pyrazines has been developed under undivided electrolytic conditions. In this protocol, neither external chemical oxidants nor transition-metal catalysts are needed, and a wide range of substituted pyrazines could be obtained from simple ketones and diamines in high efficiencies. Of note is that this electrolysis could also be extended for the construction of biheteroarenes and large π systems with good yields.
- Liu, Kun,Song, Chunlan,Wu, Jiarong,Deng, Yuqi,Tang, Shan,Lei, Aiwen
-
supporting information
p. 765 - 769
(2019/02/27)
-
- 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
-
-
- Generation of Aryl Radicals from Aryl Halides: Rongalite-Promoted Transition-Metal-Free Arylation
-
A new and practical method for the generation of aryl radicals from aryl halides is reported. Rongalite as a novel precursor of super electron donors was used to initiate a series of electron-catalyzed reactions under mild conditions. These transition-metal-free radical chain reactions enable the efficient formation of C-C, C-S, and C-P bonds through homolytic aromatic substitution or SRN1 reactions. Moreover, the synthesis of antipsychotic drug Quetiapine was performed on gram scale through the described method. This protocol demonstrated its potential as a promising arylation method in organic synthesis.
- Yu, Fazhi,Mao, Runyu,Yu, Mingcheng,Gu, Xianfeng,Wang, Yonghui
-
p. 9946 - 9956
(2019/09/04)
-
- Method for preparing bi-arene from aryl diazo salts and aryl sulfonylhydrazide
-
The invention discloses a method for preparing bi-arene from aryl diazo salts and aryl sulfonylhydrazide. The method comprises the following steps of performing denitrification coupling reaction on aryl diazo salts and aryl sulfonylhydrazide in an organic solvent under the effects of palladium catalysts, ligands and additives; after the reaction is completed, performing post-treatment to obtain the bi-arene. The method provided by the invention has the advantages that the substrate price is low; the property is stable; the operation is convenient; meanwhile, the reaction yield is high; the substrate general applicability is high.
- -
-
Paragraph 0041; 0042; 0043
(2018/10/19)
-
- A sustainable heterogenized palladium catalyst for Suzuki-Miyaura cross coupling reaction of azaheteroaryl halides in aqueous media
-
A unique recyclable Pd catalyst (‘SiO2’-NH2-Pd) for Suzuki-Miyaura coupling reaction of azaheteroaryl halides is developed. The catalytic system is working under mild aqueous condition with low Pd loading and without the use of phosphine ligand. The plausible mechanism is proposed based on the formation of undesired symmetrical biaryl from the coupling reaction of azaheteroaryl chlorides due to the oxidative homocoupling of nucleophilic arylboronic acid. This catalytic system represents an attractive and promising approach for the synthesis of azaheterobiaryls with high product yields. The catalyst has demonstrated an excellent recyclability.
- Ganesamoorthy,Muthu Tamizh,Shanmugasundaram,Karvembu
-
-
- Visible-Light Photocatalyzed Deoxygenation of N-Heterocyclic N-Oxides
-
A scalable and operationally simple method is described that allows for the chemoselective deoxygenation of a wide range of N-heterocyclic N-oxides (a total of 36 examples). This visible-light-induced protocol features the use of only commercially available reagents, room-temperature conditions, and unprecedented chemoselective removal of the oxygen atom in a quinoline N-oxide in the presence of a pyridine N-oxide in the same molecule through the judicious selection of a photocatalyst.
- Kim, Kyu Dong,Lee, Jun Hee
-
supporting information
p. 7712 - 7716
(2019/01/03)
-
- Transition-Metal-Free Decarboxylative Arylation of 2-Picolinic Acids with Arenes under Air Conditions
-
A facile, transition-metal-free, and direct decarboxylative arylation of 2-picolinic acids with simple arenes is described. The oxidative decarboxylative arylation of 2-picolinic acids with arenes proceeds readily via N-chloro carbene intermediates to afford 2-arylpyridines in satisfactory to good yields under transition-metal-free conditions. This new type of decarboxylative arylation is operationally simple and scalable and exhibits high functional-group tolerance. Various synthetically useful functional groups, such as halogen atoms, methoxycarbonyl, and nitro, remain intact during the decarboxylative arylation of 2-picolinic acids.
- Zhang, Xitao,Feng, Xiujuan,Zhou, Chuancheng,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
-
supporting information
p. 7095 - 7099
(2018/11/23)
-
- Desulfinative and denitrogenative palladium-catalyzed cross-coupling of arylsulfonyl hydrazides with aryl diazonium salts
-
Palladium-catalyzed cross-coupling of arylsulfonyl hydrazides with aryl diazonium salts to provide biaryl products under relatively mild conditions is established. This reaction proceeded smoothly with tetrabutylammonium iodide and gave the corresponding
- Shang, Yonghui
-
-
- Silica gel an efficient catalyst for one-pot synthesis of pyrazines from ethylenediamine and 1, 2-diketones and their analogs
-
A straightforward one-pot synthesis of pyrazines from ethylenediamine and 1, 2-diketones/ α-hydroxy ketone/α-bromo ketone under solvent-free conditions at room temperature is described. This environmentally benign process has the edge on previous methods in respect of workup procedure, ease and cost of reaction, and use and generation of hazardous substances. The catalyst is recovered, characterized, and proved to be recyclable for successive four runs examined with appreciable conversions.
- Chakraborty, Rakesh Ranjan,Singha, Rabindranath,Ghosh, Pranab
-
p. 373 - 378
(2018/09/29)
-
- Manganese-Catalyzed Kumada Cross-Coupling Reactions of Aliphatic Grignard Reagents with N-Heterocyclic Chlorides
-
Herein we report the use of manganese(II) chloride for the catalytic generation of C(sp 2)-C(sp 3) bonds via Kumada cross-coupling. Rapid and selective formation of 2-alkylated N-heterocyclic complexes were observed in high yields with use of 3 mol% MnCl 2 THF 1.6 and under ambient reaction conditions (21 °C, 15 min to 20 h). Manganese-catalyzed cross-coupling is tolerant toward both electron-donating and electron-withdrawing functional groups in the 5-position of the pyridine ring, with the latter resulting in an increased reaction rate and a decrease in the amount of nucleophile required. The use of this biologically and environmentally benign metal salt as a catalyst for C-C bond formation highlights its potential as a catalyst for the late-stage functionalization of pharmaceutically active N-heterocyclic molecules (e.g., pyridine, pyrazine).
- Petel, Brittney E.,Purak, Merjema,Matson, Ellen M.
-
supporting information
p. 1700 - 1706
(2018/07/13)
-
- A Zwitterionic Palladium(II) Complex as a Precatalyst for Neat-Water-Mediated Cross-Coupling Reactions of Heteroaryl, Benzyl, and Aryl Acid Chlorides with Organoboron Reagents
-
The Suzuki–Miyaura cross-coupling (SMC) reactions of several heteroaryl chlorides, benzyl chlorides, and aryl acid chlorides with (hetero)arylboron reagents have been investigated in the presence of [Pd(HL1)(PPh3)Cl2] (I) [HL1 = 3-[(2,6-diisopropylphenyl)-1-imidazolio]-2-quinoxalinide] as catalyst and K2CO3 as base in neat water. The synthesis of the heterocycle-containing biaryls required the addition of 2 mol-% of a phosphine ligand (PPh3 or X-Phos). A combination of more than 115 substrates were screened and it was found that I is a versatile catalyst that can produce heterocycle-containing biaryls, diarylmethanes, and benzophenones in moderate-to-excellent yields.
- Ramakrishna, Visannagari,Rani, Morla Jhansi,Reddy, Nareddula Dastagiri
-
p. 7238 - 7255
(2018/01/01)
-
- Selective aryl radical transfers into N-heteroaromatics from diaryliodonoium salts with trimethoxybenzene auxiliary
-
We have found that a series of trimethoxybenzene-based diaryliodonium(III) salts I (ArI+Ar’X-, where Ar = various aryl groups, Ar’ = 2,4,6-trimethoxyphenyl, X- = counterion) can exclusively cause Ar-transfers during the base-induced radical couplings with N-heteroaromatic compounds 1 by working the trimethoxybenzene ring (Ar’) as an inert coupling auxiliary. By the treatment with N-heteroaromatics 1 as the solvent, the metal-free arylations utilizing the specific salts I initiated by solid NaOH upon heating selectively produced the corresponding biaryls 2 in good yields without the formation of the trimethoxybenzene (Ar’) coupling product.
- Dohi, Toshifumi,Ueda, Shohei,Hirai, Akiko,Kojima, Yusuke,Morimoto, Koji,Kita, Yasuyuki
-
p. 1272 - 1284
(2019/11/14)
-
- Cobalt-Catalyzed Cross-Coupling Reactions of Arylboronic Esters and Aryl Halides
-
An efficient cobalt catalyst system for the Suzuki-Miyaura cross-coupling reaction of arylboronic esters and aryl halides has been identified. In the presence of cobalt(II)/terpyridine catalyst and potassium methoxide, a diverse array of (hetero)biaryls have been prepared in moderate to excellent yields.
- Duong, Hung A.,Wu, Wenqin,Teo, Yu-Yuan
-
supporting information
p. 4363 - 4366
(2017/12/05)
-
- Clean and green approach for one-pot synthesis of pyrazines from Eth-ylenediamine and 1,2-diketone or its analogues under neat reaction condition
-
Background: Compounds having N-heterocyclic moieties are of huge importance in the field of agrochemical, pharmaceutical, biological, fragrances, etc. Due to a lot of applications associated with pyrazine moieties, their synthesis has always been important for organic chemists. Method: Surfeit synthetic methodologies are documented in literature. Most of the methodologies used expensive solvents, harmful metal catalyst and all suffer from rigorous work-up procedures. An efficient, environmentally benign methodology, needs to be developed. We mixed ethylenediamine (2mmol) with 1, 2-diketone(1mmol), later, α-hydroxy ketone and α-bromo ketone on magnetic stirrer at room temperature under neat reaction condition for 5 to 10 hrs. Results: After purification by column chromatography using silica gel(60-120 mesh) and pet-ether, et-hylacetate mixture as eluent, we achieved pyrazine derivatives from moderate to high yield. Conclusio n: Efficient and clean procedure for one-pot preparation of pyrazines from ethylenediamine and 1, 2-diketones or with α-hydroxy ketone or with α-bromo ketone has been carried out under neat reaction condition at room temperature. Environmentally benign process furnishing moderate to excellent yields of the product and simple work-up giving pure products are special features of this reaction.
- Ghosh, Pranab,Chakraborty, Rakesh Ranjan
-
p. 566 - 570
(2017/09/29)
-
- Synthesis of Chiral Piperazines via Hydrogenation of Pyrazines Activated by Alkyl Halides
-
A facile method has been developed for the synthesis of chiral piperazines through Ir-catalyzed hydrogenation of pyrazines activated by alkyl halides, giving a wide range of chiral piperazines including 3-substituted as well as 2,3- and 3,5-disubstituted
- Huang, Wen-Xue,Liu, Lian-Jin,Wu, Bo,Feng, Guang-Shou,Wang, Baomin,Zhou, Yong-Gui
-
supporting information
p. 3082 - 3085
(2016/07/13)
-
- Visible-light-induced regioselective synthesis of polyheteroaromatic compounds
-
A method for visible-light-induced synthesis of polyheteroaromatics from 2-heteroaryl-substituted anilines and heteroarylalkynes was developed. The process, which uses fac-Ir(ppy)3 as the photocatalyst and tBuONO as the diazotization reagent, is highly regioselective.
- Chatterjee, Tanmay,Choi, Myung Gil,Kim, Jun,Chang, Suk-Kyu,Cho, Eun Jin
-
p. 4203 - 4206
(2016/03/19)
-
- General copper-catalyzed coupling of alkyl-, aryl-, and alkynylaluminum reagents with organohalides
-
We report the first example of a very general Cu-catalyzed cross-coupling of organoaluminum reagents with organohalides. The reactions proceed for the couplings of alkyl-, aryl-, and alkynylaluminum reagents with aryl and heteroaryl halides and vinyl bromides, affording the cross-coupled products in good to excellent yields. Both primary and secondary alkylaluminum reagents can be utilized as organometallic coupling partners. These reactions are not complicated by β-hydride elimination, and as a result rearranged products are not observed with secondary alkylaluminum reagents even for couplings with heteroaryl halides under "ligand-free" conditions. Radical clock experiment with a radical probe and relative reactivity study of Ph3Al with two haloarenes, 1-bromonaphthalene and 4-chlorobenzonitrile, having two different redox potentials indicates that the reaction does not involve free aryl radicals and radical anions as intermediates. These results combined with the result of the Hammett plot obtained by reacting Ph3Al with iodoarenes containing p-H, p-Me, p-F, and p-CF3 substituents, which shows a linear curve (R2 = 0.99) with a ρ value of +1.06, suggest that the current transformation follows an oxidative addition-reductive elimination pathway.
- Shrestha, Bijay,Thapa, Surendra,Gurung, Santosh K.,Pike, Ryan A. S.,Giri, Ramesh
-
p. 787 - 802
(2016/02/18)
-
- Metal free C-H functionalization of diazines and related heteroarenes with organoboron species and its application in the synthesis of a CDK inhibitor, meriolin 1
-
Here, we report a metal-free cross-coupling reaction of diazines and related heteroarenes with organoboron species via C-H functionalization. The optimized conditions represent a metal-free method for the activation of aryl/heteroarylboronic acids, which undergo coupling with diazines and related heteroarenes. Optimized conditions also find application in the synthesis of a pyrimidine-based potent CDK inhibitor, meriolin1.
- Thatikonda, Thanusha,Singh, Umed,Ambala, Srinivas,Vishwakarma, Ram A.,Singh, Parvinder Pal
-
p. 4312 - 4320
(2016/05/24)
-
- Carboxyamido/carbene ligated palladium (II) complex: A versatile catalyst for the synthesis of aryl-substituted heteroarenes
-
Carboxy amido/carbene ligated Pd-complex catalyzed Suzuki-Miyaura cross-coupling of aryl-boronic acids with heteroaryl bromides is described. The protocol has a broad substrate scope that includes electron-rich, electron-deficient and sterically hindered arylboronic acids and heteroaryl bromides. The catalytic activity of the catalyst has been further investigated in the coupling of 2,6-dibromopyridine with arylboronic acids.
- Vishnuvardhan Reddy, Police,Parsharamulu, Thupakula,Annapurna, Manne,Likhar, Pravin R.,Kantam, Mannepalli Lakshmi,Bhargava, Suresh
-
supporting information
p. 150 - 153
(2016/12/06)
-
- Inherent vs Apparent Chemoselectivity in the Kumada-Corriu Cross-Coupling Reaction
-
The Kumada-Corriu reaction is a powerful tool for C-C bond formation, but is seldom utilized due to perceived chemoselectivity issues. Herein, we demonstrate that high-yielding couplings can occur in the presence of many electrophilic and heterocyclic functional groups. Our strategy is mechanically based, matching oxidative addition rates with the rate of syringe pump addition of the Grignard reagent. The mechanistic reason for the effectiveness of this strategy is uncovered by continuous-infusion ESI-MS studies.
- Hua, Xiye,Masson-Makdissi, Jeanne,Sullivan, Ryan J.,Newman, Stephen G.
-
supporting information
p. 5312 - 5315
(2016/11/02)
-
- Efficient Iron-Catalyzed Kumada Cross-Coupling Reactions Utilizing Flow Technology under Low Catalyst Loadings
-
An efficient continuous flow iron-catalyzed Kumada cross-coupling was developed for the coupling of 2-chloropyrazine and various aryl Grignard reagents in presence of low catalyst loadings (0.5 mol-%). Compared to batch mode, the continuous flow approach
- Buono, Frederic G.,Zhang, Yongda,Tan, Zhulin,Brusoe, Andrew,Yang, Bing-Shiou,Lorenz, Jon C.,Giovannini, Riccardo,Song, Jinhua J.,Yee, Nathan K.,Senanayake, Chris H.
-
supporting information
p. 2599 - 2602
(2016/06/08)
-
- Oxygen-promoted Pd/C-catalyzed Suzuki-Miyaura reaction of potassium aryltrifluoroborates
-
A simple and highly efficient protocol has been developed for the Pd/C-catalyzed ligand-free Suzuki-Miyaura reaction of potassium aryltrifluoroborates. In this catalytic system, the results demonstrate that oxygen plays a positive role in the cross-coupling reaction. In addition, this catalytic system could be successfully applied to synthesize biaryl compounds containing a carbazole moiety and the catalyst was recycled seven times without significant loss of catalytic activity.
- Liu, Chun,Liu, Chao,Li, Xin-Min,Gao, Zhan-Ming,Jin, Zi-Lin
-
p. 631 - 634
(2016/05/19)
-
- Copper-Catalyzed Coupling of Triaryl- and Trialkylindium Reagents with Aryl Iodides and Bromides through Consecutive Transmetalations
-
An efficient copper(I)-catalyzed coupling of triaryl and trialkylindium reagents with aryl iodides and bromides is reported. The reaction proceeds at low catalyst loadings (2 mol %) and generally only requires 0.33 equivalents of the triorganoindium reagent with respect to the aryl halide as all three organic nucleophilic moieties of the reagent are transferred to the products through consecutive transmetalations. The reaction tolerates a variety of functional groups and sterically hindered substrates. Furthermore, preliminary mechanistic studies that entailed the synthesis and characterization of potential reaction intermediates offered a glimpse of the elementary steps that constitute the catalytic cycle.
- Thapa, Surendra,Gurung, Santosh K.,Dickie, Diane A.,Giri, Ramesh
-
supporting information
p. 11620 - 11624
(2016/02/19)
-
- Ligand-Free Copper-Catalyzed Negishi Coupling of Alkyl-, Aryl-, and Alkynylzinc Reagents with Heteroaryl Iodides
-
Reported herein is an unprecedented ligand-free copper-catalyzed cross-coupling of alkyl-, aryl-, and alkynylzinc reagents with heteroaryl iodides. The reaction proceeds at room temperature for the coupling of primary, secondary, and tertiary alkylzinc reagents with heteroaryl iodides without rearrangement. An elevated temperature (100 C) is required for aryl-heteroaryl and alkynyl-heteroaryl couplings.
- Thapa, Surendra,Kafle, Arjun,Gurung, Santosh K.,Montoya, Adam,Riedel, Patrick,Giri, Ramesh
-
supporting information
p. 8236 - 8240
(2015/07/07)
-
- Copper-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides
-
An unprecedented CuI-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides is reported. Mechanistic studies with a Cp2ZrAr2 complex revealed that Cp2Zr(Ar)(Cl) is the reactive species that undergoes transmetalation with (PN-1)CuI. In addition, experiments with radical probes indicated that the reaction proceeds via a non-radical pathway. This journal is
- Thapa, Surendra,Basnet, Prakash,Gurung, Santosh K.,Giri, Ramesh
-
supporting information
p. 4009 - 4012
(2015/03/30)
-
- Iodine-mediated oxidative annulation for one-pot synthesis of pyrazines and quinoxalines using a multipathway coupled domino strategy
-
An efficient iodine-mediated oxidative annulation of aryl acetylenes-arylethenes-aromatic ketones with 1,2-diamines for the synthesis of pyrazines and regioselective synthesis of quinoxalines is presented. A multipathway coupled domino approach has been developed for the one-pot synthesis of 1,4-diazines with high functional group compatibility.
- Viswanadham, K. K. Durga Rao,Prathap Reddy, Muktapuram,Sathyanarayana, Pochampalli,Ravi, Owk,Kant, Ruchir,Bathula, Surendar Reddy
-
supporting information
p. 13517 - 13520
(2015/01/09)
-
- 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
-
supporting information
p. 6944 - 6952
(2014/09/29)
-
- PF6-promoted ligandless suzuki-miyaura coupling reaction of potassium aryltrifluoroborates in water
-
The Suzuki-Miyaura coupling reactions of potassium aryltrifluoroborates with aryl bromides in water are promoted by the addition of [bmim]PF6 using Pd(OAc)2 as a catalyst and Na2CO3 as a base under air. The quantity of [bmim]PF6 used is crucial to the efficiency of the catalytic system. A wide range of biaryls and polyaryls can be easily prepared in good to excellent yields.
- Liu, Leifang,Dong, Yan,Pang, Bo,Ma, Jiahai
-
p. 7193 - 7198
(2014/08/18)
-
- 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
-
p. 2185 - 2189
(2014/04/17)
-
- Scope and limitation for FeSO4-mediated direct arylation of heteroarenes with arylboronic acids and its synthetic applications
-
FeSO4-mediated direct arylation of heteroarenes with arylboronic acids in the presence of K2S2O8 has been developed. A slow addition of an aqueous solution of an iron complex was crucial in the arylation. Scope and limitation of the heteroarenes and arylboronic acids are discussed. Furthermore, the direct arylation was applied to the formal total synthesis botryllazine B and sodium channel inhibitor.
- Komeyama, Kimihiro,Nagao, Yuya,Abe, Manabu,Takaki, Ken
-
p. 301 - 313
(2014/03/21)
-
- Direct arylation of substituted pyridines with arylboronic acids catalyzed by iron(II) oxalate
-
The direct arylation of substituted pyridines with several arylboronic acids has been developed. This transformation could proceed readily at ambient temperature using inexpensive reagents: iron(II) oxalate as a catalyst, potassium persulfate as a co-oxidant, which can afford the arylated products in mild to good yields. The mechanism is presumed to proceed through a nucleophilic radical addition to the pyridines with in situ reoxidation.
- Huang, Yibo,Guan, Dan,Wang, Liang
-
p. 1294 - 1298
(2015/02/05)
-
- Ortho-(Dimesitylboryl)phenylphosphines: Positive boryl effect in the palladium-catalyzed suzuki-miyaura coupling of 2-chloropyridines
-
Catalytic systems combining ortho-(dimesitylboryl) phenylphosphines and palladium precursors have been evaluated in the Suzuki-Miyaura couplings of chloro-N-heterocycles, in particular 2-chloro pyridines, with arylboronic acids. The Lewis basic character of the substrates does not interfere with the Lewis acidic site of the ligands, even for a substrate featuring free NH2 groups. The influence of several reaction parameters has been studied and the ortho-dimesitylboryl moiety was actually found to substantially enhance the catalytic performance. The role of this group has been examined using preformed phosphine-borane/Pd complexes and the formation of an original phosphine/h4-boratabutadiene complex has been identified as a possible deactivation pathway. Regioselective coupling of 2,6-dichloro-3-nitropyridine with phosphine-borane/Pd catalysts has also been explored, and sequential double cross-couplings were found to give a direct and efficient access to unsymmetrical 2,6-diarylpyridines.
- Malacea, Raluca,Chahdoura, Faouzi,Devillard, Marc,Saffon, Nathalie,Gomez, Montserrat,Bourissou, Didier
-
p. 2274 - 2284
(2013/10/01)
-
- (π-Allyl)Pd complexes containing N-heterocyclic carbene and pseudohalogen ligands - Synthesis, reactivity toward organic isothiocyanates and isocyanides, and their catalytic activity in suzuki-miyaura cross-couplings
-
Dinuclear (π-allyl)palladium chlorides, [(π-allyl)Pd(μ-Cl)] 2, were cleaved by N-heterocyclic carbenes (NHCs) to give mononuclear (π-allyl)palladium-NHC chlorides, [(π-allyl)Pd(Cl)(NHC)] (1-6) [NHC = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPR), 1,3-bis(2,6- diisopropylphenyl)-4,5-dihydroimidazol-2-ylidine (SIPR), 1,3-bis(2,4,6- trimethylphenyl)imidazol-2-ylidene (IMes)]. Complexes 1-6 were subsequently treated with aqueous NaN3, KSCN, KOCN, and CF3COOAg to produce the corresponding mononuclear (π-allyl)palladium-NHC pseudohalogen complexes, [(π-allyl)Pd(X)(NHC)] (X = N3, NCS, SCN, NCO, CF 3COO) (7-30). These products could also be obtained by treating dinuclear pseudohalogen-bridged Pd complexes, [(π-allyl)Pd(μ-X)] 2, which were prepared by replacing the μ-Cl ligand in [(π-allyl)Pd(μ-Cl)]2, with aqueous NaN3, KSCN, KOCN, or CF3COOAg, followed by cleavage with the NHCs. Reactions of [(π-allyl)Pd(N3)(NHC)] with organic isothiocyanates (R-NCS) or CH3O(CO)C≡CO(CO)CH3 resulted in selective 1,3-dipolar cycloaddition into the Pd-azido bond to give heterocyclic compounds. By contrast, analogous reactions of [(η3-allyl)Pd(N 3)(IPr)] with an organic isocyanide (R-NC: R = tert-butyl, benzyl) gave the adduct [(η3-allyl)Pd(N3)(IPr)]·(R-NC) as the only product or a mixture of the adduct and a dipolar cycloaddition product, [(η3-allyl)Pd{CN4(R)}(IPr)], depending on the isocyanides used. Finally, a series of (π-allyl)Pd-NHC pseudohalogen complexes, [(π-allyl)Pd(X)(NHC)], exhibited high catalytic activity in Suzuki-Miyaura cross-coupling reactions of aryl chlorides with arylboronic acids. A series of (π-allyl)palladium complexes containing N-heterocyclic carbene and pseudohalogen ligands are prepared and their reactivity toward organic isothiocyanates and isocyanides is studied. Suzuki-Miyaura cross-coupling reactions of aryl chlorides with aryl boronic acid catalyzed by these (π-allyl)palladium complexes are reported. Copyright
- Kim, Hyun-Kyung,Lee, Jung-Hyun,Kim, Yong-Joo,Nu Zheng, Zhen,Lee, Soon W.
-
p. 4958 - 4969
(2013/10/21)
-
- Imidazolium supported palladium-chloroglycine complex: Recyclable catalyst for Suzuki-Miyaura coupling reactions
-
1-Glycyl-3-methyl imidazolium chloride-palladium(II) complex [[Gmim]Cl-Pd(II)] was found to be a catalyst for the Suzuki-Miyaura reaction with excellent yields with high turnover number (6.5 × 102-9.4 × 102).
- Karthikeyan, Parasuraman,Vanitha, Arumugam,Radhika, Pachaiappan,Suresh, Kannan,Sugumaran, Arunachalam
-
supporting information
p. 7193 - 7197
(2013/12/04)
-
- 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
-
supporting information
p. 5378 - 5381
(2013/11/06)
-
- 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
-
supporting information
p. 1203 - 1205
(2013/10/22)
-
- Palladium-catalyzed cross-coupling reaction of functionalized aryl- and heteroarylbismuthanes with 2-halo(or 2-Triflyl)azines and -diazines
-
The palladium-catalyzed cross-coupling of highly functionalized organobismuthanes with 2-halo(or 2-triflyl)pyridines, -pyrimidines, -pyrazines, and -pyridazines is reported. The reaction tolerates numerous functional groups, including aldehydes. The synthesis of a shelf-stable (formylphenyl)bismuth reagent and its use in a cross-coupling reaction is also described. The palladium-catalyzed cross-coupling of highly functionalized organobismuthanes with 2-halo(or 2-triflyl)pyridines, -pyrimidines, -pyrazines, and -pyridazines is reported. The reaction tolerates numerous functional groups, including aldehydes. The synthesis of a shelf-stable (formylphenyl)bismuth reagent and its use in cross-coupling reactions is also described. Copyright
- Petiot, Pauline,Gagnon, Alexandre
-
supporting information
p. 5282 - 5289
(2013/09/02)
-
- Development of a palladium-catalyzed decarboxylative cross-coupling of (2-azaaryl)carboxylates with aryl halides Dedicated to Professor Melanie Sanford on receipt of the Tetrahedron Young Investigator Award
-
A catalytic method for the decarboxylative coupling of 2-(azaaryl) carboxylates with aryl halides is described. The decarboxylative cross-coupling presented is mediated by a system catalytic in both palladium and copper without requiring stoichiometric amounts of organometallic reagents or organoboronic acids. This method circumvents additional synthetic steps required to prepare 2-azaaryl organometallics and organoborates as nucleophilic coupling partners, which are prone to protodemetallation and protodeborylation and produce potentially toxic byproducts.
- Haley, Christopher K.,Gilmore, Christopher D.,Stoltz, Brian M.
-
p. 5732 - 5736
(2013/07/11)
-
- Iron-catalyzed cross-coupling of electron-deficient heterocycles and quinone with organoboron species via innate C-H functionalization: Application in total synthesis of pyrazine alkaloid botryllazine A
-
Here, we report an iron-catalyzed cross-coupling reaction of electron-deficient heterocycles and quinone with organoboron species via innate C-H functionalization. Iron(II) acetylacetonate along with oxidant (K 2S2O8) and phase-transfer catalyst (TBAB) under open flask conditions efficiently catalyzed the cross-coupling of pyrazine with arylboronic acids and gave monoarylated products in good to excellent yields. Optimized conditions also worked for other heterocylces such as quinoxalines, pyridines, quinoline, and isoquinoline as well as quinones. In addition, we demonstrated as a first example its application for the synthesis of anticancer marine pyrazine alkaloid botryllazine A.
- Singh, Parvinder Pal,Aithagani, Sravan Kumar,Yadav, Mahipal,Singh, Varun Pratap,Vishwakarma, Ram A.
-
p. 2639 - 2648
(2013/04/24)
-
- A highly efficient and aerobic protocol for the synthesis of N-heteroaryl substituted 9-arylcarbazolyl derivatives via a palladium-catalyzed ligand-free Suzuki reaction
-
A palladium-catalyzed aerobic and ligand-free Suzuki reaction in aqueous ethanol has been developed for the synthesis of N-heteroaryl substituted 9-arylcarbazolyl derivatives. A number of N-heteroaryl halides, namely 2-halogenated pyridines, 2-bromoquinoline, 5-bromopyrimidine and 2-chloropyrazine, were coupled with 4-(9H-carbazol-9-yl)phenylboronic acid (CPBA) or 9-phenyl-9H-carbazol-3-ylboronic acid (PCBA) efficiently to afford good to excellent yields in a short reaction time. Moreover, the catalytic system of Pd(OAc)2-EtOH/H2O-K2CO3 was successfully extended to the cross-couplings of N-heteroaryl halides with various arylboronic acids. The results demonstrated that the cross-coupling reaction in the present protocol was promoted by oxygen.
- Rao, Xiaofeng,Liu, Chun,Qiu, Jieshan,Jin, Zilin
-
supporting information
p. 7875 - 7883
(2013/06/27)
-