- Rapid microwave-enhanced, solventless Sonogashira coupling reaction on alumina
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A microwave-enhanced, solventless Sonogashira coupling reaction has been developed. Terminal alkynes couple with aryl or alkenyl iodide on palladium- doped alumina in the presence of triphenylphosphine and cuprous iodide to provide high yields of products. (C) 2000 Published by Elsevier Science Ltd.
- Kabalka, George W.,Wang, Lei,Namboodiri, Vasudevan,Pagni, Richard M.
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- The CuFe2O4@SiO2@ZrO2/SO42-/Cu nanoparticles: An efficient magnetically recyclable multifunctional Lewis/Br?nsted acid nanocatalyst for the ligand- and Pd-free Sonogashira cross-coupling reaction in water
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Herein, the synthesis and application of copper-incorporated sulfated zirconium oxide supported on CuFe2O4 NPs (CuFe2O4@SiO2@ZrO2/SO42-/Cu NPs) as a novel Lewis/Br?nsted acid nanocatalyst were studied for the Sonogashira C-C cross-coupling reaction. The fabricated CuFe2O4@SiO2@ZrO2/SO42-/Cu catalyst exhibited efficient activity for a large variety of aryl iodides/bromides and, most importantly, aryl chlorides in water and in the presence of NaOH as a base in short reaction times. The catalyst was fully characterized by FTIR, TG-DTG, VSM, XRD, EDX, FE-SEM and TEM analyses. A synergetic effect could be considered to have arisen from the various Lewis acid and Br?nsted acid sites present in the catalyst. The efficient incorporation of copper into zirconia provided a robust highly stable hybrid, which prevented any metal leaching, whether from the magnetite moiety and/or Cu sites in the reaction mixture. Moreover, the catalyst was successfully recovered from the mixture by a simple external magnet and reused for at least 9 consecutive runs. Zero metal leaching, stability, consistency with a variety of substrates, fast performance, cost-effectiveness, environmental friendliness, and preparation with accessible and cheap materials are some of the advantages and highlights of the current protocol.
- Nasseri, Mohammad Ali,Alavi, Seyyedeh Ameneh,Kazemnejadi, Milad,Allahresani, Ali
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- Effect of solvent polarity on N-H insertion versus rearrangement of alkylidene carbenes
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Alkylidene carbenes, when generated from o-aminobenzophenones and lithiated trimethylsilyldiazomethane, give a mixture of alkyne (by rearrangement) and indole (by N-H insertion). It has been found that this ratio of indole to acetylene shows a linear dependence on the polarity of the ethereal solvent.
- Taber, Douglass F.,Plepys, Raymond A.
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- A convenient synthesis of pyrrolopyridines and 2-substituted indoles by gold-catalyzed cycloisomerization
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We have developed a gold-catalyzed intramolecular cyclization of variously substituted acetylenic amines under mild conditions, which yields pyrrolopyridines and 2-substituted indoles, quantitatively. The cycloisomerization of acetylenic amines was achieved with AuCl3 as catalyst without the use of base, acid or N-protecting group.
- Majumdar,Samanta,Chattopadhyay
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- Magnetic Cu–Schiff base complex with an ionic tail as a recyclable bifunctional catalyst for base/Pd-free Sonogashira coupling reaction
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Abstract: A Cu(II)–Schiff base complex containing imidazolium ionic phase was prepared and decorated on γ-Fe2O3 magnetic nanoparticles (γ-Fe2O3@Cu(II)IL-SB) and found to be an efficient catalyst for the Pd- and base-free Sonogashira coupling reaction. The heterogeneous catalyst was characterized by FTIR spectroscopy, UV–visible spectroscopy, FE-SEM, TEM, XRD spectroscopy, EDX spectroscopy, VSM, ICP spectroscopy, and atomic absorption spectroscopy. The coupling reactions were performed using the catalyst under mild and base-free conditions, and high-to-excellent yields were obtained for a variety of substrates. The catalyst demonstrates a dual-functionality arising from metal sites and imidazolium moieties and that the later plays a base role. Reusability and stability of γ-Fe2O3@Cu(II)IL-SB were studied several times, which can be reused up to eight consecutive runs with at least reduction in catalytic activity. Also, the mechanism of this bifunctional catalytic system was thoroughly investigated. Graphic abstract: A new and efficient method has been developed for the base- and Pd-free Sonogashira cross-coupling reactions of aryl halides with phenyl acetylene using a bifunctional γ-Fe2O3@Cu(II)IL-SB catalyst with imidazolium moiety under mild conditions[Figure not available: see fulltext.].
- Nasseri, Mohammad Ali,Rezazadeh, Zinat,Kazemnejadi, Milad,Allahresani, Ali
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- Copper-Catalyzed Aerobic Oxidative Cyclization of 2-Alkynylanilines with Nitrosoarenes: Synthesis of Organic Solid Mechanoluminescence Compounds of 4-Oxo-4 H-cinnolin-2-ium-1-ide
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An efficient Cu(I)/DMAP/air system for the one-pot synthesis of 4-oxo-4H-cinnolin-2-ium-1-ides, which are often difficult to prepare by traditional routes from substituted 2-alkynylanilines and nitrosoarenes, was developed. These 4-oxo-4H-cinnolin-2-ium-1-ides have practical applications as mechanoluminescent materials. Preliminary mechanistic experiments were performed, and a plausible mechanism for this tandem process is proposed. The use of an inexpensive copper catalyst and molecular oxygen as the oxygen source and the oxidant make this an attractive green protocol with potential synthetic applications.
- Fang, Xiaolan,Cao, Ji,Ding, Weijie,Jin, Huile,Yu, Xiaochun,Wang, Shun
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supporting information
p. 1228 - 1233
(2021/02/20)
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- Solvent-Dependent Cyclization of 2-Alkynylanilines and ClCF2COONa for the Divergent Assembly of N-(Quinolin-2-yl)amides and Quinolin-2(1 H)-ones
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Herein, we present an expedient Cu-catalyzed [5 + 1] cyclization of 2-alkynylanilines and ClCF2COONa to divergent construction of N-(quinolin-2-yl)amides and quinolin-2(1H)-ones by regulating the reaction solvents. Notably, nitrile acts as a solvent and performs the Ritter reactions. ClCF2COONa is used as a C1 synthon in this transformation, which also represents the first example for utilization of ClCF2COONa as an efficient desiliconization reagent. The current protocol involves in situ generation of isocyanide, copper-activated alkyne, Ritter reaction and protonation.
- Wang, Ya,Zhou, Yao,Ma, Xingxing,Song, Qiuling
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supporting information
p. 5599 - 5604
(2021/08/01)
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- Photochemical Approach to the Cyclohepta[b]indole Scaffold by Annulative Two-Carbon Ring-Expansion
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We report on the implementation of the concept of a photochemically elicited two-carbon homologation of a π-donor–π-acceptor substituted chromophore by triple-bond insertion. Implementing a phenyl connector between the slide-in module and the chromophore enabled the synthesis of cylohepta[b]indole-type building blocks by a metal-free annulative one-pot two-carbon ring expansion of the five-membered chromophore. Post-irradiative structural elaboration provided founding members of the indolo[2,3-d]tropone family of compounds. Control experiments in combination with computational chemistry on this multibond reorganization process founded the basis for a mechanistic hypothesis.
- Tymann, Dina Christina,Benedix, Lars,Iovkova, Lyuba,Pallach, Roman,Henke, Sebastian,Tymann, David,Hiersemann, Martin
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supporting information
p. 11974 - 11978
(2020/08/21)
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- Diorganyl tellurides as substrates in Sonogashira coupling reactions under mild conditions
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A new method of Sonogashira coupling reactions between diorganyl tellurides and terminal alkynes is reported. The coupling reactions are performed using Pd(dppf)Cl2 as a catalyst, CuI as a co-catalyst in the presence of K2CO3 in DMSO. The reactions are carried out at room temperature and completed within 2 h when phenyl acetylene is used as a terminal alkyne. For aliphatic terminal alkynes, such as 1-hexyne and 1-octyne, an elevated temperature and longer reaction time are needed for the completion of the reactions. This process results in good yields of Sonogashira coupling products which is applicable for diaryl, divinyl and dialkynyl tellurides but not applicable for dialkyl tellurides.
- Zhang, Shaozhong,Ailneni, Chandra,Al-Mohammed Baqer, Osamah,Lolla, Mahati,Mannava, Bala Bharathi,Siraswal, Parvinlal,Yen, Changchi,Jin, Jin
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supporting information
p. 217 - 225
(2019/11/22)
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- A Co-Cu bimetallic magnetic nanocatalyst with synergistic and bifunctional performance for the base-free Suzuki, Sonogashira, and C-N cross-coupling reactions in water
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A novel magnetically recyclable bimetallic catalyst was prepared by anchoring imidazolium moiety and PEG chains on Fe3O4 NPs and named as Fe3O4?PEG/Cu-Co. It was found to be a powerful catalyst for the Sonogashira, Suzuki, and C-N cross-coupling reactions in water as a green solvent without the need for any external base. Fe3O4?PEG/Cu-Co was well characterized with FT-IR, FE-SEM, TEM, VSM, EDX, ICP, UV-visible, CV, and XPS analyses. Optimum ranges of parameters such as time, temperature, and amount of catalyst were investigated by Design-Expert 10.0.7 software for C-C Suzuki, Sonogashira, and C-N cross-coupling reactions to find the optimum conditions. The catalyst was compatible with a variety of aryl halides and N-arenes and gave favorable coupling products with good to high yields for all of them. Hot filtration and Hg poisoning tests involving the nanocatalyst revealed the stability, low metal leaching, and heterogeneous nature of the catalyst. Reaction mechanisms were proposed by study of the UV-visible spectra in situ as well as hydroquinone tests during the progress of reactions. In situ XPS analysis was also used to study the reaction mechanism. To prove the synergistic performance of Co and Cu in the catalyst, its various homologues were synthesized and applied to a model reaction separately, and then their catalytic activities were investigated. Finally, the catalyst could be recovered from the reaction mixture simply, and reused for several cycles with a minimum loss in catalytic activity and performance.
- Allahresani, Ali,Kazemnejadi, Milad,Nasseri, Mohammad Ali,Rezazadeh, Zinat
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p. 10645 - 10660
(2020/09/18)
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- LiHMDS-Promoted Palladium-Catalyzed Sonogashira Cross-Coupling of Aryl Fluorides with Terminal Alkynes
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A highly efficient Pd-catalyzed Sonogashira coupling of various aryl fluorides with terminal alkynes in the presence of LiHMDS was developed. Both unreactive electron-rich fluoroarenes and electron-poor fluoroarenes proceeded smoothly and afforded the cor
- He, Jingjing,Yang, Kang,Zhao, Jianhong,Cao, Song
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supporting information
p. 9714 - 9718
(2019/11/28)
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- Sonogashira Couplings Catalyzed by Fe Nanoparticles Containing ppm Levels of Reusable Pd, under Mild Aqueous Micellar Conditions
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Nanoparticles derived from FeCl3 containing the ligand XPhos and only 500 ppm Pd effect Sonogashira couplings in water between rt and 45 °C. The entire aqueous reaction medium can be easily recycled using an "in-flask" extraction. Several tande
- Handa, Sachin,Jin, Bo,Bora, Pranjal P.,Wang, Ye,Zhang, Xiaohua,Gallou, Fabrice,Reilly, John,Lipshutz, Bruce H.
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p. 2423 - 2431
(2019/03/08)
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- Phosphinito palladium(ii) complexes as catalysts for the synthesis of 1,3-enynes, aromatic alkynes and ynones
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An air-stable phosphinito palladium(ii) complex (Ph1-Phoxide) has been found to be an efficient catalyst in the formation of C-C bonds. The coupling of terminal alkynes formed gem-1,3-enynes as the only reaction products. Aromatic alkynes can be synthesized from the coupling of terminal alkynes and haloaromatic compounds (Sonogashira coupling). The phosphinito palladium(ii) complex also catalyses the coupling between acyl chlorides and terminal alkynes (Sonogashira coupling), furnishing ynones in excellent yields.
- Islas,Cárdenas,Gavi?o,García-Ríos,Lomas-Romero,Morales-Serna
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p. 9780 - 9789
(2017/02/15)
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- Synthesis of substituted benzofurans and indoles by Zn-catalyzed tandem Sonogashira-cyclization strategy
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Transition metal catalyzed cross-coupling reactions are one of the predominant strategies for the construction of heterocyclic structures which possess wide applications in the synthesis of natural products, pharmaceuticals, polymers, etc. Due to the vast importance of substituted benzofurans and indoles, numerous synthetic methodologies have been introduced for their synthesis. Among these methods, transition metal catalyzed cyclization reactions possess a unique position. In this manuscript, we disclose the first and efficient zinc-catalyzed protocol for the cyclization reactions of alkynes with 2-iodophenol and 2-iodoaniline leading to benzofurans and indoles respectively via a tandem Sonogashira coupling-cyclization process. Among the different metal catalysts, zinc has enormous potential due to its great availability, non-toxicity, eco-friendly and inexpensive nature. Zn(II) with N,N′-dimethylethylenediamine represents a suitable and efficient catalytic system for the desired tandem CC coupling-cyclization reactions, and a broad spectrum of functional groups are tolerated during the catalysis. A variety of substituted benzofurans and indoles have been successfully prepared in moderate to good yields under this new protocol.
- Thankachan, Amrutha P.,Sindhu, Kallikkakam S.,Ujwaldev, Sankuviruthiyil M.,Anilkumar, Gopinathan
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p. 536 - 540
(2017/01/16)
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- One-Pot Synthesis of Substituted Benzo[b]furans and Indoles from Dichlorophenols/Dichloroanilines Using a Palladium-Dihydroxyterphenylphosphine Catalyst
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Disubstituted benzo[b]furans were synthesized by ortho-selective Sonogashira coupling of dichlorophenols and terminal alkynes, followed by cyclization and Suzuki-Miyaura coupling in one pot, using a palladium-dihydroxyterphenylphosphine (Cy-DHTP) catalyst. The use of substoichiometric amounts of tetrabutylammonium chloride was effective in accelerating the Suzuki-Miyaura coupling. This protocol was also successfully applied to the one-pot synthesis of disubstituted indoles from dichloroaniline derivatives.
- Yamaguchi, Miyuki,Akiyama, Tomoyo,Sasou, Hirohisa,Katsumata, Haruka,Manabe, Kei
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p. 5450 - 5463
(2016/07/14)
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- Alkyne-substituted diminazene as G-quadruplex binders with anticancer activities
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G-quadruplex ligands have been touted as potential anticancer agents, however, none of the reported G-quadruplex-interactive small molecules have gone past phase II clinical trials. Recently it was revealed that diminazene (berenil, DMZ) actually binds to
- Wang, Changhao,Carter-Cooper, Brandon,Du, Yixuan,Zhou, Jie,Saeed, Musabbir A.,Liu, Jinbing,Guo, Min,Roembke, Benjamin,Mikek, Clinton,Lewis, Edwin A.,Lapidus, Rena G.,Sintim, Herman O.
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supporting information
p. 266 - 275
(2016/05/10)
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- Supported palladium nanoparticles-catalyzed decarboxylative coupling approaches to aryl alkynes, indoles and pyrrolines synthesis
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The polystyrene supported palladium (Pd@PS) nanoparticles (NPs) catalyzed decarboxylative coupling (DC) of arylhalides and alkynyl carboxylic acids was developed for the synthesis of diaryl alkynes. Indole and 3-pyrroline heterocycles were also synthesized from 2-iodo anilines/amino benzocycloheptene bromide and alkynyl carboxylic acids, following a domino decarboxylative coupling-cyclization (DCC) approach under the same catalytic conditions. The combined anchoring and catalytic behaviour of Pd@PS makes the process favourable for the product formation.
- Reddy, C. Bal,Bharti, Richa,Kumar, Sandeep,Das, Pralay
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p. 71117 - 71121
(2016/08/05)
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- Unusual 1,2-aryl migration in Pd(II)-catalyzed aza-Wacker-type cyclization of 2-alkenylanilines
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Inspired by the Hegedus aza-Wacker indole synthesis, we were intrigued with the fate of the aminopalladation intermediate if syn β-hydrogen is made inaccessible or unavailable. In contrast to our previously reported β-carbon elimination, cyclization of a
- Youn, So Won,Lee, So Ra
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p. 4652 - 4656
(2015/04/27)
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- TBHP mediated oxidation of N-2-alkynylphenyl α-amino carbonyl compounds to oxalic amides using visible light photoredox catalysis and their application in the synthesis of 2-aryl indoles
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A visible light promoted and TBHP mediated oxidative reaction of N-2-alkynylphenyl α-amino carbonyl compounds to N-2-alkynylphenyl oxalic amides was developed. In the presence of CuBr and photocatalyst Ru(bpy)3Cl2·6H2O, the reaction proceeded smoothly to afford the corresponding oxalic amides under the irradiation of a 26 W compact fluorescence bulb at room temperature. Furthermore, N-2-alkynylphenyl oxalic amides could be subsequently transferred to 2-aryl indoles without an additional deacylation step through a favored 5-endo-dig N-cyclization process using AgNO3 as catalyst.
- Liu, Wei,Liu, Sheng,Xie, Hongqi,Qing, Zhixing,Zeng, Jianguo,Cheng, Pi
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p. 17383 - 17388
(2015/03/04)
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- Metal-free C-H amination for indole synthesis
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An effective metal-free C-H amination of N-Ts-2-alkenylanilines by using DDQ as an oxidant has been developed to afford a diverse range of substituted indoles. This protocol is operationally simple and robust, obviates the need of expensive transition-metal catalysts, and offers a broad substrate scope. A mechanism involving a radical cation generated by SET and a migratorial process via a phenonium ion intermediate is proposed.
- Jang, Young Ho,Youn, So Won
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supporting information
p. 3720 - 3723
(2014/08/05)
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- Palladium-free synthesis of unsymmetrical diarylethynes by cross-coupling reaction of alkynylboronates with aryl iodides catalyzed by CuCl
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A series of unsymmetrical diarylethynes have been synthesized by the copper-catalyzed cross-coupling reaction of alkynylboronates with aryl iodides in high to excellent yields under palladium-free conditions. A wide range of substrates bearing an electron-donating or an electron-withdrawing substituent on the aromatic ring are compatible with this reaction.
- Ogawa, Daisuke,Li, Jing,Suetsugu, Masato,Jiao, Jiao,Iwasaki, Masayuki,Nishihara, Yasushi
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p. 518 - 521
(2013/02/23)
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- Gold and palladium combined for the Sonogashira coupling of aryl and heteroaryl halides
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A highly efficient gold and palladium combined methodology for the Sonogashira coupling of a wide array of electronically and structurally diverse aryl and heteroaryl halides is described. The orthogonal reactivity of the two metals shows high selectivity and extreme functional group tolerance in Sonogashira coupling. A brief mechanistic study reveals that the gold acetylide intermediate enters into the palladium catalytic cycle at the transmetalation step. Georg Thieme Verlag Stuttgart.New York.
- Panda, Biswajit,Sarkar, Tarunk.
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p. 817 - 829
(2013/04/10)
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- Cesium carbonate-promoted hydroamidation of alkynes: Enamides, indoles and the effect of iron(III) chloride
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A series of enamide derivatives was prepared by a simple procedure for the hydroamidation of alkynes with amides and sulfonamides. The use of such a mild base as cesium carbonate promotes the latter transformation, and the addition of catalytic amounts of iron(III) chloride has a beneficial effect in the outcome of some of the presented hydroamidation reactions. A range of indoles was also synthesized from ortho-alkynylanilides by both complementary procedures, which proved to be useful for the construction of the indolo[1,2-c]quinazoline tetracyclic system from an ortho-(2-aminophenylalkynyl)anilide. Copyright
- Herrero, Maria Teresa,De Sarralde, Jokin Diaz,Sanmartin, Raul,Bravo, Laura,Dominguez, Esther
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p. 3054 - 3064
(2013/01/15)
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- Ruthenium-catalyzed C-H silylation of methylboronic acid using a removable α-directing modifier on the boron atom
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Ruthenium-catalyzed C-H silylation of methylboronic acid was achieved by use of 2-(1H-pyrazol-3-yl)aniline as a removable α-directing modifier on the boron atom. Crosscoupling of the product, i.e., (phenyldimethylsilyl) methylpinacolborane, with aryl halides proceeded in the presence of a [PdCl 2(dppf)] catalyst and CsOH as a base.
- Ihara, Hideki,Ueda, Akinori,Suginome, Michinori
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supporting information; experimental part
p. 972 - 974
(2012/01/19)
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- Ready synthesis of free N-H 2-arylindoles via the copper-catalyzed amination of 2-bromo-arylacetylenes with aqueous ammonia and sequential intramolecular cyclization
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A wide range of free N-H 2-arylindoles were synthesised via the copper(ii)-catalyzed amination of 2-bromo-arylacetylenes with aqueous ammonia and sequential intramolecular cyclization. The convenience and atom economy of aqueous ammonia, and the low cost of the copper catalytic system make this protocol readily superior in practical application. The Royal Society of Chemistry 2011.
- Wang, Huifeng,Li, Yaming,Jiang, Linlin,Zhang, Rong,Jin, Kun,Zhao, Defeng,Duan, Chunying
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scheme or table
p. 4983 - 4986
(2011/08/05)
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- Palladium-catalyzed synthesis of indoles via ammonia cross-coupling-alkyne cyclization
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The synthesis of indoles via the metal-catalyzed cross-coupling of ammonia is reported for the first time; the developed protocol also allows for the unprecedented use of methylamine or hydrazine as coupling partners. These Pd/Josiphos-catalyzed reactions proceed under relatively mild conditions for a range of 2-alkynylbromoarenes.
- Alsabeh, Pamela G.,Lundgren, Rylan J.,Longobardi, Lauren E.,Stradiotto, Mark
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supporting information; experimental part
p. 6936 - 6938
(2011/08/06)
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- Multicomponent cascade reactions: A novel and expedient approach to functionalized indoles by an unprecedented nucleophilic addition- heterocyclization-oxidative alkoxycarbonylation sequence
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A novel multicomponent cascade process is reported, based on the sequential combination between an initial nucleophilic attack step to an imine moiety and a palladium-catalyzed oxidative heterocyclization-alkoxycarbonylation process. By this new process, five simple molecules [2-alkynylaniline imines, alcohol (ROH), carbon monoxide (CO), alcohol (ROH), and oxygen (O2)] are sequentially activated, selectively leading to high value-added functionalized indole derivatives in a single operation. Copyright
- Gabriele, Bartolo,Veltri, Lucia,Salerno, Giuseppe,Mancuso, Raffaella,Costa, Mirco
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scheme or table
p. 3355 - 3363
(2011/03/17)
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- Microwave-assisted synthesis of indole- and azaindole-derivatives in water via cycloisomerization of 2-alkynylanilines and alkynylpyridinamines promoted by amines or catalytic amounts of neutral or basic salts
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An efficient methodology is described and exploited for the preparation of differently substituted indoles and azaindoles via microwave-assisted cycloisomerization in water of 2-alkynylanilines and alkynylpyridinamines, which is promoted by catalytic amounts of neutral or basic salts or by stoichiometric weak organic bases. Good to high yields in the cyclization can be achieved for a variety of 2-amino(hetero)aryl alkynes. Reactions are run without any added metal catalyst. A comparison with the cycloisomerization conducted under conventional heating is also described. An efficient methodology is described for the preparation of differently substituted 1H-indoles and 1H-azaindoles via microwave-assisted cycloisomerization in water of 2-alkynylanilines and alkynylpyridinamines, promoted by catalytic amounts of neutral or basic salts or by weak organic bases.
- Carpita, Adriano,Ribecai, Arianna,Stabile, Paolo
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experimental part
p. 7169 - 7178
(2010/10/01)
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- A practical heterogeneous catalyst for the suzuki, sonogashira, and stille coupling reactions of unreactive aryl chlorides
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(Chemical Equation Present) Practical catalyst: A magnetic nanoparticle-supported palladium catalyst was developed for the highly efficient heterogeneous Suzuki, Sonogashira, and Stille couplings of a wide variety of aryl chlorides. Furthermore, the catalyst could be recycled by facile magnetic separation without any loss of activity.
- Jin, Myung-Jong,Lee, Dong-Hwan
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supporting information; experimental part
p. 1119 - 1122
(2010/05/17)
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- On the catalytic duo PdCl2(PPh3)2/AuCl(PPh3) that cannot effect a Sonogashira-type reaction: a correction
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In contrast to the observation made by the Laguna group, we report that the combination of PdCl2(PPh3)2 and AuCl(PPh3) makes a unique catalytic system that allows Sonogashira-type cross-coupling of both aryl and alkyl alkynes with aryl halides in excellent yields.
- Panda, Biswajit,Sarkar, Tarun K.
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experimental part
p. 301 - 305
(2010/03/26)
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- Microwave-assisted synthesis of indole-derivatives via cycloisomerization of 2-alkynylanilines in water without added catalysts, acids, or bases
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An unprecedented green methodology is described for the preparation of differently substituted indoles via microwave-assisted cycloisomerization of 2-alkynylaniline derivatives in water. Moderate to good yields in the cyclization can be achieved for a variety of 2-aminoaryl alkynes. Reactions are run without any added metal catalyst, acid, or base, and do not take place by applying conventional heating.
- Carpita, Adriano,Ribecai, Arianna
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supporting information; experimental part
p. 6877 - 6881
(2010/05/03)
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- Convenient copper- and solvent-free Sonogashira-type alkynylation of aryl iodides and bromides using Pd EnCat
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A straightforward methodology is described for the copper- and solvent-free alkynylations of aryl iodides and bromides using 0.1-0.01 mol % of Pd as Pd EnCat 40 or TPP30. High yielding reactions can be achieved under aerobic conditions for a variety of activated and deactivated aryl iodides; a few examples with aryl bromides are also described. Microwave irradiation is able to enhance yields and rates of these reactions.
- Carpita, Adriano,Ribecai, Arianna
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scheme or table
p. 204 - 207
(2009/04/19)
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- Sonogashira cross-coupling reactions and construction of the indole ring system using a robust, silica-supported palladium catalyst
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The use of a recyclable silica-supported palladium catalyst in Sonogashira couplings and indole syntheses using a range of functionalised substrates is described. The catalyst is shown to be both robust and versatile, effecting the synthesis of 2-phenylindole in quantitative yield without the need for N-protection, a copper co-catalyst, a base, or a solvent. Georg Thieme Verlag Stuttgart.
- Tyrrell, Elizabeth,Whiteman, Leon,Williams, Neil
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experimental part
p. 829 - 835
(2009/07/25)
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- One-Pot synthesis of indoles and aniline derivatives from nitroarenes under hydrogenation condition with supported gold nanoparticles
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One-pot sequences of hydrogenation/hydroamination to form indoles from (2-nitroaryl)alkynes and hydrogenation/reductive amination to form aniline derivatives from nitroarenes and aldehydes were catalyzed by Au nanoparticles supported on Fe2O3. Nitro group selective hydrogenations and successive reactions were efficiently catalyzed under the conditions.
- Yamane, Yoshihiro,Liu, Xiaohao,Hamasaki, Akiyuki,Ishida, Tamao,Haruta, Masatake,Yokoyama, Takushi,Tokunaga, Makoto
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supporting information; experimental part
p. 5162 - 5165
(2009/12/28)
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- A general palladium-catalyzed animation of aryl halides with ammonia
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A study was conducted to demonstrate palladium(Pd)-catalyzed amination of aryl halides with ammonia. The active catalyst was formed in situ from Pd(OAc)2, along with air- and moisture stable phosphines as pre-catalysts. It was found that the productivity of the catalyst system was similar to that of competitive Pd and phosphine systems. It was demonstrated that the novel electron-rich sterically demanding phosphine ligand was unable to be displaced from the palladium by ammonia to a significant extent, which prevented the deactivation of the catalyst by the ligand. It was also demonstrated that the Pd-catalyzed animation worked at ambient pressure. It was observed that the optimized system showed an excellent substrate scope including deactivated, electron-neutral, and activated halides, o-, m- p-substituted substrates, aryl chlorides, and heterocycles.
- Schulz, Thomas,Torborg, Christian,Enthaler, Stephan,Schaeffner, Benjamin,Dumrath, Andreas,Spannenberg, Anke,Neumann, Helfried,Boerner, Armin,Beller, Matthias
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experimental part
p. 4528 - 4533
(2009/12/24)
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- One-pot/four-step/palladium-catalyzed synthesis of indole derivatives: The combination of heterogeneous and homogeneous systems
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One-pot, four-step syntheses of indoles using both solid-supported heterogeneous and homogeneous palladium catalysts and reagents were carried out. Such a combination of these two-phase catalysts and reagents causes a dramatic increase in yield, and it is a simple process. The presented methodology is effective for four-step reactions to provide various functionalized indoles.
- Sakai, Hayato,Tsutsumi, Ken,Morimoto, Tsumoru,Kakiuchia, Kiyomi
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supporting information; experimental part
p. 2498 - 2502
(2009/08/14)
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- Indium-HI-mediated one-pot reaction of 1-(2-arylethynyl)-2-nitroarenes to 2-arylindoles
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While 1-(2-arylethynyl)-2-nitroarenes were reduced to 2-(2-arylethynyl)anilines in the presence of indium and InCl3 in THF/H2O (v/v = 5/1) at 50 °C, 1-(2-arylethynyl)-2-nitroarenes were reductively cyclized to 2-arylindoles with good yields in the presence of indium and aqueous HI in benzene.
- Kim, Ji Sook,Han, Joon Hee,Lee, Jung June,Jun, Young Moo,Lee, Byung Min,Kim, Byeong Hyo
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p. 3733 - 3738
(2008/09/20)
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- Palladium-free copper-catalyzed Sonogashira cross-coupling at room temperature
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We have developed an efficient method for the palladium-free copper-catalyzed Sonogashira cross-coupling of o-iodoacetanilide derivatives with alkynes at room temperature; the corresponding coupling products were obtained in good to excellent yields using copper(I) iodide/N-methylpyrrolidine- 2-carboxamide as the catalyst. This inexpensive catalyst system has high tolerance towards various functional groups in the substrates. This represents the lowest reaction temperatures for copper-catalyzed Sonogashira cross-coupling thus far. Georg Thieme Verlag Stuttgart.
- Jiang, Huimin,Fu, Hua,Qiao, Renzhong,Jiang, Yuyang,Zhao, Yufen
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body text
p. 2417 - 2426
(2009/04/06)
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- HYDANTOIN DERIVATIVES USEFUL AS ANTIBACTERIAL AGENTS
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This invention relates to compounds of the Formula (I): or a pharmaceutically acceptable salt, solvate, ester or isomer thereof, which is useful for the treatment of diseases or conditions mediated by LpxC.
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Page/Page column 46-47
(2008/06/13)
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- Compounds for the treatment of inflammatory disorders and microbial diseases
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This invention relates to compounds of the Formulae (I)-(IX): or a pharmaceutically acceptable salt, solvate, ester or isomer thereof, which can be useful for the treatment of diseases or conditions mediated by MMPs, aggrecanase, ADMP, LpxC, ADAMs, TACE,
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Page/Page column 46
(2008/06/13)
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- Palladium-tetraphosphine complex: An efficient catalyst for the alkynylation of ortho-substituted aryl bromides
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The tetraphosphine cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl) cyclopentane in combination with [Pd(C3H5)Cl]2 affords a very efficient catalyst for the alkynylation of ortho-substituted aryl bromides. A wide variety of substituents such as phenyl, trifluoromethyl, acetyl, formyl or nitrile, are tolerated. High turnover numbers can be obtained with most of these aryl bromides. The coupling of sterically very congested aryl bromides such as 9-bromoanthracene or 2,4,6-triisopropylbromobenzene also proceeds in good yields.
- Feuerstein, Marie,Berthiol, Florian,Doucet, Henri,Santelli, Maurice
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p. 1281 - 1289
(2007/10/03)
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- Sonogashira coupling with aqueous ammonia directed to the synthesis of azotolane derivatives
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Sonogashira coupling with aqueous ammonia is tolerable for the reaction of aryl iodides or terminal alkynes bearing an azobenzene group. The reaction of (4-heptyloxyphenyl)ethyne with (4-heptyloxyphenyl)-(4-iodophenyl)diazene in the presence of 1 mol% of
- Mohamed Ahmed, Mohamed S.,Mori, Atsunori
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p. 9977 - 9982
(2007/10/03)
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- Sonogashira coupling and cyclization reactions on alumina: A route to aryl alkynes, 2-substituted-benzo[b]furans and 2-substituted-indoles
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A solventless, microwave-enhanced Sonogashira coupling reaction of aromatic iodides with terminal alkynes on potassium fluoride doped alumina in the presence of palladium powder, cuprous iodide, and triphenylphosphine has been developed. The reaction can be utilized to prepare aryl alkynes in excellent yields. The coupling of o-iodophenol with terminal alkynes leads to the formation 2-substituted-benzo[b]furans. Whereas the coupling of o-iodoanilines with terminal alkynes generates indole products. An in situ desilylation reaction was also developed.
- Kabalka, George W.,Wang, Lei,Pagni, Richard M.
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p. 8017 - 8028
(2007/10/03)
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- Convenient reduction of nitrobenzenes to anilines using electrochemically generated nickel
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The reduction of nitrobenzenes with electrogenerated nickel in DMF gave anilines without affecting the alkenyl, alkynyl, halo, acetyl, methoxy, cyano, ethoxycarbonyl, formyl, benzyloxy, and phenylsulfonylamino groups at room temperature in a short time. The nickel was easily prepared by electrolysis in 0.3 M Et4NBF4-DMF solution under an argon atmosphere at a constant current (10 mA/cm2) and can be stored under argon at -20 °C for at least a week. The reduction of nitrobenzenes with electrogenerated nickel in DMF gave anilines without affecting the alkenyl, alkynyl, halo, acetyl, methoxy, cyano, ethoxycarbonyl, formyl, benzyloxy, and phenylsulfonylamino groups at room temperature in a short time. The nickel was easily prepared by electrolysis in 0.3 M Et4NBF4-DMF solution under an argon atmosphere at a constant current (10 mA/cm2) and can be stored under argon at -20 °C for at least a week.
- Yasuhara,Kasano,Sakamoto
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p. 2301 - 2303
(2007/10/03)
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- A study of vinyl radical cyclization onto the azido group by addition of sulfanyl, stannyl, and silyl radicals to alkynyl azides
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Thermal radical reactions of azidoalkynes 2, 8, 14, and 21a-c with thiols 1a-c afford 2-sulfanylvinyl radicals by selective addition of sulfanyl radicals to the triple bond. 1-Phenylvinyl radicals 23 and 30a, as well as vinyl radical 30b, undergo fast 5-cyclization onto the aromatic azide function to give cyclized indoles. In contrast, both 1-phenyl (15, 17) and 1-alkyl (3a,b, 9) vinyl radicals fail to add to their aliphatic azido substituents and exclusively undergo cyclization onto the aromatic sulfanyl ring and H transfer from the thiol precursor. Azidoalkynes 14 and 21a react with Bu3SnH and TMSS under radical conditions to give instead the corresponding amines as a result of preferential attack of Bu3Sn · and (TMS)3Si · radicals on the azido group rather than on the triple bond. Evidence is provided that alkyl radical cyclizations onto azides are not feasible in the presence of thiol, in contrast with the reported utility of these cyclization reactions in the presence of Bu3SnH and TMSS.
- Montevecchi, Pier Carlo,Navacchia, Maria Luisa,Spagnolo, Piero
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p. 1219 - 1226
(2007/10/03)
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- Condensed heteroaromatic ring systems. XXIV. Palladium-catalyzed cyclization of 2-substituted phenylacetylenes in the presence of carbon monoxide
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The palladium-catalyzed reaction of 2-alkynylanilines and 2-alkynylphenols in the presence of carbon monoxide and methanol under basic conditions gave the sequential cyclization/carbonylation products, methyl 2-substituted indole and benzo[b]furan-3-carbo
- Kondo, Yoshinori,Shiga, Futoshi,Murata, Naoko,Sakamoto, Takao,Yamanaka, Hiroshi
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p. 11803 - 11812
(2007/10/02)
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- Synthesis of Aryl- and Vinylacetylene Derivatives by Copper-Catalyzed Reaction of Aryl and Vinyl Iodides with Terminal Alkynes
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The coupling reaction of aryl iodides with terminal alkynes by using a catalyst system of CuI-PPh3 in the presence of K2CO3 as base gives the corresponding arylated alkynes in excellent yields.Addition of PPh3 is essential for the reaction to proceed catalytically.Vinyl iodides also react smoothly with the alkynes to give enyne compounds with retention of the configurations.While DMF and DMSO can be used as solvents, DMSO is found to be effective for the reaction with aliphatic terminal alkynes.A reaction mechanism involving initial formation of copper acetylide species coordinated by PPh3 followed by reaction of aryl and vinyl iodides is proposed.
- Okuro, Kazumi,Furuune, Makoto,Enna, Masahiro,Miura, Masahiro,Nomura, Masakatsu
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p. 4716 - 4721
(2007/10/02)
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