- Polysulfide Anions as Visible Light Photoredox Catalysts for Aryl Cross-Couplings
-
Polysulfide anions are endowed with unique redox properties, attracting considerable attentions for their applications in alkali metals-sulfur batteries. However, the employment of these anionic species in redox catalysis for small molecule synthesis remains underdeveloped due to their moderate-poor electrochemical potential in the ground state, whereas some of them are characterized by photoabsorptions in visible spectral regions. Herein, we disclose the use of polysulfide anions as visible light photoredox catalysts for aryl cross-coupling reactions. The reaction design enables single-electron reduction of aryl halides upon the photoexcitation of tetrasulfide dianions (S42-). The resulting aryl radicals are engaged in (hetero)biaryl cross-coupling, borylation, and hydrogenation in a redox catalytic regime involving S4?-/S42- and S3?-/S32- redox couples.
- Li, Haoyu,Tang, Xinxin,Pang, Jia Hao,Wu, Xiangyang,Yeow, Edwin K. L.,Wu, Jie,Chiba, Shunsuke
-
supporting information
p. 481 - 487
(2021/01/13)
-
- UiO-66 microcrystals catalyzed direct arylation of enol acetates and heteroarenes with aryl diazonium salts in water
-
UiO-66 is a classic Metal–organic framework (MOF) that constructed by zirconium cations and terephthalate with high chemical and thermal stability. Using pristine UiO-66 nanocrystals as the catalysts, the carbon–carbon bond formation based on denitrogenat
- Sun, Zhong-Hua,Chen, Wang,Qian, Bing-Bing,Wang, Liang,Yu, Binxun,Chen, Qun,He, Ming-Yang,Zhang, Zhi-Hui
-
-
- Air- And moisture-stable Xantphos-ligated palladium dialkyl complex as a precatalyst for cross-coupling reactions
-
Although xantphos has been employed in a variety of palladium-catalyzed cross-coupling reactions, there has been little progress in developing Xantphos-ligated precatalysts. In this report, we describe a Xantphos-ligated palladium dialkyl complex that acts as a powerful precatalyst for C-N, C-S, and C-C cross-coupling reactions. This precatalyst is air- and moisture stable but can be thermally activated in the absence of external reagents. Additionally, potential catalyst inhibitors are not generated during the precatalyst activation. This complex thus represents a convenient alternative to previously reported classes of Xantphos-ligated precatalysts.
- Takahashi, Rina,Kubota, Koji,Ito, Hajime
-
supporting information
p. 407 - 410
(2020/01/13)
-
- Perylenequinonoid-catalyzed photoredox activation for the direct arylation of (het)arenes with sunlight
-
Naturally occurring perylenequinonoid pigments (PQPs) have attracted considerable attention owing to their excellent properties of photosensitization. They have been widely investigated as an aspect of photophysics and photobiology. However, their applications in photocatalysis are yet to be explored. We report here that sunlight along with 1 mol% cercosporin, which is one of the perylenequinonoid pigments, catalyzes the direct C-H bond arylation of (het)arenes by a photoredox process with good regioselectivity and broad functional group compatibility. Furthermore, a gram-scale reaction with great conversions of substrates was achieved even by a cercosporin-containing supernatant without organic solvent extraction and purification after liquid fermentation. Thus we set up a bridge between microbial fermentation and organic photocatalysis for chemical reactions in a sustainable, environmentally friendly manner.
- Zhang, Shiwei,Tang, Zhaocheng,Bao, Wenhao,Li, Jia,Guo, Baodang,Huang, Shuping,Zhang, Yan,Rao, Yijian
-
supporting information
p. 4364 - 4369
(2019/05/10)
-
- Molecular Design of Donor-Acceptor-Type Organic Photocatalysts for Metal-free Aromatic C?C Bond Formations under Visible Light
-
Metal-free and photocatalytic radical-mediated aromatic C?C bond formations offer a promising alternative pathway to the conventional transition metal-catalyzed cross-coupling reactions. However, the formation of aryl radicals from common precursors such as aryl halides is highly challenging due to their extremely high reductive potential. Here, we report a structural design strategy of donor-acceptor-type organic photocatalysts for visible light-driven C?C bond formations through the reductive dehalogenation of aryl halides. The reduction potential of the photocatalysts could be systematically aligned to be ?2.04 V vs. SCE via a simple heteroatom engineering of the donor-acceptor moieties. The high reductive potential of the molecular photocatalyst could reduce various aryl halides into aryl radicals to form the C?C bond with heteroarenes. The designability of the molecular photocatalyst further allowed the synthesis of a high LUMO (lowest unoccupied molecular orbital) polymer photocatalyst by a self-initiated free radical polymerization without compromising its LUMO level. (Figure presented.).
- Wang, Lei,Byun, Jeehye,Li, Run,Huang, Wei,Zhang, Kai A. I.
-
p. 4312 - 4318
(2018/10/02)
-
- Insights into the Catalytic Activity of [Pd(NHC)(cin)Cl] (NHC=IPr, IPrCl, IPrBr) Complexes in the Suzuki–Miyaura Reaction
-
The influence of C4,5-halogenation on palladium N-heterocyclic carbene complexes and their activity in the Suzuki–Miyaura reaction were investigated. Two [Pd(NHC)(cin)Cl] complexes bearing IPrCl and IPrBr ligands (IPr=1,3-bis(2,6-diisopropyl-phenyl)imidazol-2-ylidene; cin=cinnamyl) were synthesized. After determining the electronic and steric properties of these ligands, their properties were compared to those of [Pd(IPr) (cin)Cl]. The three palladium complexes were studied by using DFT calculations to delineate their behavior in the activation step leading to the putative 12-electron active catalyst. Experimentally, their catalytic activity in the Suzuki–Miyaura reaction involving a wide range of coupling partners (30 entries) at low catalyst loading was studied.
- Izquierdo, Frédéric,Zinser, Caroline,Minenkov, Yury,Cordes, David B.,Slawin, Alexandra M. Z.,Cavallo, Luigi,Nahra, Fady,Cazin, Catherine S. J.,Nolan, Steven P.
-
p. 601 - 611
(2017/12/26)
-
- C-H arylation reactions through aniline activation catalysed by a PANI-g-C3N4-TiO2 composite under visible light in aqueous medium
-
A PANI (polyaniline)-g-C3N4-TiO2 composite was prepared and found to be efficient for radical C-H arylation reactions. The arylation process involved coupling of in situ generated aryl diazonium salts from aniline with heteroarenes, enol acetates or benzoquinones under visible light in aqueous medium or pure water. A broad range of substrates survived the reaction conditions to provide the desired products in moderate to good yields. Scale-up (10 mmol) synthesis was also achieved. This semiconductor photocatalyst showed good photocatalytic performance and stability. Recycle studies showed that this composite could be readily recovered and a slight decrease in the catalytic activity was observed after ten consecutive runs.
- Wang, Liang,Shen, Jun,Yang, Sen,Liu, Wenjie,Chen, Qun,He, Mingyang
-
supporting information
p. 1290 - 1296
(2018/03/26)
-
- Polyaniline-Induced Arylation with Arenediazonium Salts Derived from Anilines
-
A catalytic amount of a reduced form of polyaniline (a redox-active π-conjugated polymer) was found to induce C?H direct arylation of (hetero)arenes with arenediazonium salts prepared from anilines with methanesulfonic acid (MeSO3H) and tert-butyl nitrite (tBuONO). The difficult part of this method is the coexistence of an oxidant and a reductant in this sequential diazotization and arylation system; diazotization requires weak oxidants such as alkyl nitrites, whereas the arylation is induced by a reductant. This was achieved by the careful control of the amount of tBuONO (1.0 equivalent) for the diazotization step, and sequential arylation using 5 mol % of the polyaniline. The reaction took place under mild conditions without any metals or strong bases at room temperature, and the amino group is a formal leaving group. The scope of the substrates demonstrates the versatility in the combination of anilines with a variety of functional groups and several (hetero)arenes. Two-directional arylation for the synthesis of an unsymmetrical 1,4-diarylated (furyl and pyrrolyl groups) benzene was achieved, using mono-Boc-protected 1,4-phenylenediamine as a substrate. This shows potential for the synthesis of more complicated oligoarene compounds.
- Hata, Dai,Moriuchi, Toshiyuki,Hirao, Toshikazu,Amaya, Toru
-
supporting information
p. 7703 - 7709
(2017/06/06)
-
- Visible-Light-Promoted Arylation Reactions Photocatalyzed by Bismuth(III) Oxide
-
Bismuth(III) oxide has been successfully applied as a photocatalyst in the arylation of heteroarenes with diazonium salts. With a low catalyst loading (1 to 5 mol-%), this cheap and nontoxic semiconductor could efficiently promote the formation of the aryl radical under visible light irradiation. The arylated products are obtained in moderate to good yields, and the process admits straightforward scale-up (10 mmol; 1 mol-% Bi2O3). In two cases, the diazonium salt was generated in situ and used in the photocatalytic arylation in a tandem manner. Besides heteroarenes, Bi2O3 also catalyzed the arylation of differently substituted alkenes and alkynes, thus representing a viable and practical alternative to the more commonly used ruthenium complexes and organic dyes.
- Buglioni, Laura,Riente, Paola,Palomares, Emilio,Pericàs, Miquel A.
-
supporting information
p. 6986 - 6990
(2017/12/26)
-
- Wavelength Selective Generation of Aryl Radicals and Aryl Cations for Metal-Free Photoarylations
-
Photochemical reactions have become an important tool for organic chemists. Visible (solar) light can be conveniently adopted, however, only when using colored organic compounds or in photocatalyzed processes induced by visible light absorbing photocatalysts. Herein we demonstrate that a photolabile, colored moiety could be incorporated in a colorless organic compound with the aim of generating highly reactive intermediates upon exposure to visible (solar) light. Arylazo sulfones, colored thermally stable derivatives of aryl diazonium salts, were used as valuable substrates for the photoinduced metal-free synthesis of (hetero)biaryls with no need of a (photo)catalyst or of other additives to promote the reaction. Noteworthy, selective generation of aryl radicals and aryl cations can be attained at will by varying the irradiation conditions (visible light for the former and UVA light for the latter).
- Crespi, Stefano,Protti, Stefano,Fagnoni, Maurizio
-
p. 9612 - 9619
(2016/11/02)
-
- Polyaniline-Induced C-H Arylation of Arenes with Arenediazonium Salts
-
A reduced form of polyaniline has been shown to induce direct arylation of an arenediazonium salt with an arene (Gomberg-Bachmann reaction) to give the cross-coupling product in moderate to good yields under mild conditions. Various arenediazonium salts and arenes, including heteroarenes such as furans, thiophenes, and pyrroles, are employed for the reaction. The most favorable combination of substrates is an electron-poor arenediazonium salt with an electron-rich heteroarene. Investigation of the mechanism by reactions with radical scavengers and experiments on kinetic isotope effects indicated the occurrence of a radical chain reaction initiated by one-electron reduction of an arenediazonium salt by the polyaniline. Only 1 mol % (based on aniline tetramer) of the polyaniline is required for the cross-coupling reaction to occur. This reaction proceeds under metal-free conditions and with no need for photonic activation.
- Amaya, Toru,Hata, Dai,Moriuchi, Toshiyuki,Hirao, Toshikazu
-
p. 16427 - 16433
(2015/11/10)
-
- Fluorosolvatochromism of furanyl- and thiophenyl-substituted acetophenones
-
A series of para-substituted acetophenones bearing a furanyl or a thiophenyl moiety show a large Stokes-shift, which is a function of various solvent properties. Photophysical properties such as emission lifetime of the compounds have been determined using time-correlated-single photon counting to secure the intrinsic fluorescence behaviour. The solvent dependent position of the UV/Vis emission band max,em of the compounds has been measured in 26 various solvents. The influence of the solvent on max,em is of very complex nature and mathematically analysed by multiple square linear solvation energy (LSE)-correlation analysis using Catalán's four-solvent parameter set. Solvent acidity has a strong influence on the bathochromic shift of 2,5-disubstituted furan derivatives compared to the non-5-substituted furan and thiophene derivatives, which show a contrary behaviour. Therefore, the 5-cyanofuranyl-substituted acetophenone derivative is useful as a probe for measuring environmental properties by fluorescence spectroscopy.
- Friebe, Nadine,Schreiter, Katja,Kübel, Joachim,Dietzek, Benjamin,Moszner, Norbert,Burtscher, Peter,Oehlke, Alexander,Spange, Stefan
-
p. 5171 - 5179
(2015/07/07)
-
- Visible-light-photocatalyzed metal-free C-H heteroarylation of heteroarenes at room temperature: A sustainable synthesis of biheteroaryls
-
An efficient C-H heteroarylation of heteroarenes is achieved through visible-light photoredox-catalyzed diazotization of heteroarylamines in situ by tBuONO at room temperature. A library of functionalized biheteroaryls is obtained by using this protocol.
- Maity, Pintu,Kundu, Debasish,Ranu, Brindaban C.
-
p. 1727 - 1734
(2015/05/27)
-
- A general approach to N-heterocyclic carbenes with a fused tetracyclic core: Ligands for suzuki-miyaura cross-coupling reaction
-
The synthesis of an N-heterocyclic carbene (NHC) based on a tetracyclic scaffold by using simple, general, and scalable chemistry is disclosed. The developed route is suitable for introducing multiple substitutions on the tetracyclic scaffold. The utility of the present NHC as a ligand in the Suzuki-Miyaura cross-coupling reaction is demonstrated with a low catalyst loading. Copyright
- Sutar, Revannath L.,Kumar, Vinod,Shingare, Rahul D.,Thorat, Shridhar,Gonnade, Rajesh,Reddy, D. Srinivasa
-
supporting information
p. 4482 - 4486
(2014/08/05)
-
- Organogold(I) phosphanes in palladium-catalyzed cross-coupling reactions in aqueous media
-
Cross-coupling reaction of organogold(I) phosphanes with organic electrophiles in aqueous media has been investigated. Reactions between isolated aryl-, alkenyl-, or alkynylgold(I) phosphanes and aryl halides or triflates, alkenyl halides, and allyl acetates proceed under palladium catalysis conditions at room temperature or 80 °C in water with THF as a co-solvent. The coupling reactions give good yields and are highly versatile and chemoselective, allowing the presence of free amino or hydroxy groups in the electrophile. This methodology was applied to the preparation of substituted phenylalanine esters in a demonstration that gold(I) organometallics are suitable reagents for metal-catalyzed cross-coupling reactions under protic conditions. Organogold(I) phosphanes react with organic electrophiles in aqueous media under palladium catalysis conditions. The reactions take place at room temperature or 80 °C in water with THF as co-solvent. The coupling is versatile and chemoselective and allows the presence of free amino and hydroxy groups in the electrophile. Copyright
- Pena-Lopez, Miguel,Sarandeses, Luis A.,Perez Sestelo, Jose
-
p. 2545 - 2554
(2013/06/05)
-
- Synthesis of 2-substituted furans by iron- and palladium-catalyzed coupling reactions
-
The synthesis of 2-substituted furans via palladium- and iron-catalyzed coupling utilizing 2-bromofuran is described. Whereas palladium-catalyzed Suzuki coupling effectively provided the corresponding aryl furans, little or no product was obtained by palladium-catalyzed coupling with various alkyl nucleophiles. Iron-catalyzed coupling proved effective for the synthesis of primary and secondary alkyl furans in modest yields and aryl furans in low yields. Georg Thieme Verlag Stuttgart New York.
- Haner, Jamie,Jack, Kelsey,Nagireddy, Jaipal,Raheem, Mohammed Abdul,Durham, Robin,Tam, William
-
experimental part
p. 731 - 738
(2011/04/24)
-
- An efficient protocol for the palladium-catalysed Suzuki-Miyaura cross-coupling
-
The palladacyclic catalyst precursor received by ortho-palladation of ([1,1′-biphenyl]-2-yloxy)diisopropyl-phosphine represents a highly active system for Suzuki-Miyaura cross-coupling reactions when used in neat water. An efficient, broadly applicable and sustainable aqueous protocol was developed using 2.5 eq. of Na2CO3 as base, allowing the reaction to be performed under air and at ambient temperature with Pd loadings of 0.04 mol%. Coupling products are obtained in high yields and excellent purity by simple filtration with no organic solvents needed throughout the whole reaction. A broad variety of functional groups are tolerated and a large number of substrates can be applied with this protocol. The crystal structure of the palladacyclic catalyst precursor is presented as well as investigations targeting the nature of catalyst activation and the active catalytic species.
- Marziale, Alexander N.,Jantke, Dominik,Faul, Stefan H.,Reiner, Thomas,Herdtweck, Eberhardt,Eppinger, Joerg
-
supporting information; experimental part
p. 169 - 177
(2011/03/23)
-
- Efficient procedure for the preparation of 2-bromofuran and its application in the synthesis of 2-arylfurans
-
A simple, straightforward, and scalable procedure for the preparation of 2-bromofuran using N-bromosuccinimide (NBS) in dimethylformamide (DMF) is reported. The described preparation is conducted on a 20 to 50g scale and does not require extractive workup procedures or chromatographic purifications. To illustrate the synthetic applications of 2-bromofuran, palladium-catalyzed Suzuki coupling reactions of the prepared 2-bromofuran with various aryl boronic acids were investigated, and moderate to good yields of 2-arylfurans were obtained. Copyright Taylor & Francis Group, LLC.
- Raheem, Mohammed-Abdul,Nagireddy, Jaipal R.,Durham, Robin,Tam, William
-
experimental part
p. 2138 - 2146
(2010/08/13)
-
- SLOW RELEASE OF ORGANOBORONIC ACIDS IN CROSS-COUPLING REACTIONS
-
A method of performing a chemical reaction includes reacting a compound selected from the group consisting of an organohalide and an organo-pseudohalide, and a protected organoboronic acid represented by formula (I) in a reaction mixture: R1-B-T; where R1 represents an organic group, T represents a conformationalIy rigid protecting group, and B represents boron having sp3 hybridization. When unprotected, the corresponding organoboronic acid is unstable by the boronic acid neat stability test. The reaction mixture further includes a base having a pKB of at least 1 and a pal ladium catalyst. The method further includes forming a cross-coupled product in the reaction mixture.
- -
-
Page/Page column 65-66
(2010/04/27)
-
- Palladium on charcoal-catalyzed ligand-free Stille coupling
-
An efficient ligand-free Stille coupling reaction catalyzed by palladium on charcoal was developed. Tetraphenyltin was reacted with a variety of aryl halides including aryl chlorides using LiCl as an additive. The reactions of tributyl organotin compounds with aryl iodides were effectively expedited by the addition of LiF. These reactions efficiently proceeded without a phosphine or arsenic ligand and no leached palladium was detected in the reaction mixture.
- Yabe, Yuki,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
-
experimental part
p. 8654 - 8660
(2010/11/19)
-
- Facile palladium catalyzed Suzuki-Miyaura coupling in air and water at ambient temperature
-
A new palladacyclic catalyst yields high activities in aqueous Suzuki-Miyaura coupling at room temperature. Using an optimized protocol, a broad range of products can be isolated in good to excellent yields and high purity by simple filtration.
- Marziale, Alexander N.,Faul, Stefan H.,Reiner, Thomas,Schneider, Sven,Eppinger, Joerg
-
supporting information; experimental part
p. 35 - 38
(2010/05/17)
-
- Scope of the suzuki-Miyaura cross-coupling reactions of potassium heteroaryltrifluoroborates
-
A wide variety of bench-stable potassium heteroaryltrifluoroborates were prepared, and general reaction conditions were developed for their cross-coupling to aryl and heteroaryl halides. The cross-coupled products were obtained in good to excellent yields. This method represents an efficient and facile installation of heterocyclic building blocks onto preexisting organic substructures.
- Molander, Gary A.,Canturk, Belgin,Kennedy, Lauren E.
-
supporting information; experimental part
p. 973 - 980
(2009/07/11)
-
- Sustainable Suzuki-Miyaura reaction catalyzed by Pd(OAc)2 immobilized on reversed-phase alumina
-
Employing Pd(OAc)2 immobilized on amorphous N,N- diethylaminopropyl alumina, Suzuki-Miyaura coupling of aryl halide with arylboronic acid was realized in 50% aqueous ethanol at room temperature, which enabled repeated use up to four times in 96% average yield and achieved a turnover number of 15 000. Georg Thieme Verlag Stuttgart.
- Hagiwara, Hisahiro,Keon, Hyeok Ko,Hoshi, Takashi,Suzuki, Toshio
-
p. 611 - 613
(2008/12/22)
-
- Synthesis and SAR of heteroaryl-phenyl-substituted pyrazole derivatives as highly selective and potent canine COX-2 inhibitors
-
The discovery of heteroaryl-phenyl-substituted pyrazole derivatives as canine selective COX-2 inhibitors is described. Structure-activity relationship (SAR) studies of this class of compounds led to the identification of compound 1 which demonstrated a ca
- Cheng, Hengmiao,Lundy DeMello, Kristin M.,Li, Jin,Sakya, Subas M.,Ando, Kazuo,Kawamura,Kato, Tomoki,Rafka, Robert J.,Jaynes, Burton H.,Ziegler, Carl B.,Stevens, Rod,Lund, Lisa A.,Mann, Donald W.,Kilroy, Carolyn,Haven, Michelle L.,Nimz, Erik L.,Dutra, Jason K.,Li, Chao,Minich, Martha L.,Kolosko, Nicole L.,Petras, Carol,Silvia, Annette M.,Seibel, Scott B.
-
p. 2076 - 2080
(2007/10/03)
-
- Palladium-catalyzed chemoselective cross-coupling of acyl chlorides and organostannanes
-
Chemoselective cross-coupling of aliphatic and aromatic acyl chlorides with aryl-, heteroaryl-, and alkynylstannanes proceeds in up to 98% yield using 2.5 mol % of bis(di-tert-butylchlorophosphine)palladium(II) dichloride as the precatalyst. Various functional groups including aryl chlorides and bromides that usually undergo oxidative addition to palladium complexes bearing phosphinous acid or dialkylchlorophosphine ligands are tolerated. This procedure allows convenient ketone formation and eliminates inherent limitations of Friedel-Crafts acylations such as substituent-directing effects and typical reactivity requirements of Lewis acid-catalyzed electrophilic aromatic substitutions.
- Lerebours, Rachel,Camacho-Soto, Alexandra,Wolf, Christian
-
p. 8601 - 8604
(2007/10/03)
-
- A novel thiourea ligand applied in the Pd-catalyzed Heck, Suzuki and Suzuki carbonylative reactions
-
A novel C2 symmetrical and sterically bulky thiourea ligand 1 has been successfully applied to Heck, Suzuki and Suzuki-type carbonylative coupling reactions under aerobic conditions. Since the metal-sulfur bond in the thiourea complexes is stronger than the metal-phosphorus bond of typical phosphine complexes, thiourea ligands generally do not easily dissociate from the metal center under catalytic conditions, which establishes the thiourea 1-based palladium complexes as effective catalysts for the palladium-catalyzed cross-coupling reactions.
- Mingji, Dai,Liang, Bo,Wang, Cuihua,You, Zejin,Xiang, Jing,Dong, Guangbin,Chen, Jiahua,Yang, Zhen
-
p. 1669 - 1673
(2007/10/03)
-
- Scope and limitation of the nickel-catalyzed coupling reaction between lithium borates and mesylates
-
Coupling reaction of aryl borates and mesylates derived from phenols and enols was studied. Mesylates with an electron-with-drawing group or ring were highly reactive at room temperature in the presence of NiCl2(PPh3)2 to furnish the coupling products in good yields.
- Kobayashi, Yuichi,William, Anthony D.,Mizojiri, Ryo
-
-
- Palladium-Catalyzed Stille Couplings with Fluorous Tin Reactants
-
A new class of "fluorous" aryl tin reactants was investigated for use in the Stille coupling. Fluorous compounds partition into a fluorocarbon (fluorous) phase in a fluorous/organic extraction. The coupling of tris[(perfluorohexyl)ethyl]phenyl tin [(C6F13CH2CH2)3SnPh] with bromobenzene occurs smoothly in DMF/THF (1/1) at 80 °C in the presence of a catalytic amount of PdCl2(PPh3)2 and 3 equiv of LiCl. Partitioning between CH2Cl2 and FC-72 (a mixture of perfluorohexanes) provided biphenyl in 90% yield from the organic phase and tris[(perfluorohexyl)ethyl]tin chloride in > 90% yield from the fluorous phase. The tin chloride was reacted with phenylmagnesium bromide to regenerate the starting tin reactant. A study to optimize reaction conditions is described, and the scope of the method is illustrated with 20 coupling reactions. The beneficial effect of lithium choride is an unusual feature of the reaction, but it also promotes the formation of some fluoroalkyl-coupled products. These can be suppressed by adding CuI. The paper describes a prototypical example of how to render a tin reactant fluorous. This process should be advantageous in small- and large-scale synthesis, as well as in automated synthesis.
- Hoshino, Masahide,Degenkolb, Peter,Curran, Dennis P.
-
p. 8341 - 8349
(2007/10/03)
-
- A convenient synthesis of polysubstituted phenylphenols from substituted anilines
-
2' and 4'-Substituted arylfurans react with DMAD in the presence of Lewis acid to afford Diels-Alder adducts with good yields; a subsequent spontaneous or an acid-induced ?-elimination leads to polysubstituted phenylphenols.
- Maggiani, Alain,Tubul, Ariette,Brun, Pierre
-
p. 631 - 633
(2007/10/03)
-
- Nickel-catalyzed coupling reaction of lithium organoborates and aryl mesylates possessing an electron withdrawing group
-
In the presence of NiCl2(PPh3)2 as catalyst, p-methoxycarbonylphenyl mesylate (5) and tosylate (6) react with lithium arylborates 4 (Ar = 2-furyl, Ph, p-Me-Ph, p-MeO-Ph) at room temperature to afford the coupling products in high yields. Similarly, mesylates 9-11 coupled with these borates 4 efficiently.
- Kobayashi, Yuichi,Mizojiri, Ryo
-
p. 8531 - 8534
(2007/10/03)
-
- PALLADIUM-CATALYZED ARYLATION OF FURAN, THIOPHENE, BENZOFURAN AND BENZOTHIOPHENE
-
Treatment of ?-electron sufficient aromatic heterocycles such as furan, thiophene, benzofuran and benzothiophene with aryl bromides in the presence of tetrakis(triphenyphosphine)palladium gave the corresponding 2-aryl aromatic heterocycles.
- Ohta, Akihiro,Akita, Yasuo,Ohkuwa, Teruya,Chiba, Mari,Fukunaga, Ryuichi,et al.
-
p. 1951 - 1958
(2007/10/02)
-
