- Cobalt(II)-Catalyzed Csp2-H Alkynylation/Annulation with Terminal Alkynes: Selective Access to 3-Methyleneisoindolin-1-one
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A highly efficient cobalt(II)-catalyzed alkynylation/annulation of terminal alkynes assisted by an N,O-bidentate directing group is described. This protocol is characterized by wide substrate scope utilizing cheap cobalt catalysts, and offers a new approa
- Zhang, Lin-Bao,Hao, Xin-Qi,Liu, Zhan-Jiang,Zheng, Xin-Xiang,Zhang, Shou-Kun,Niu, Jun-Long,Song, Mao-Ping
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- An efficient mesoporous carbon nitride (g-C3N4) functionalized Pd catalyst for carbon-carbon bond formation reactions
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Metal nanoparticles in pristine form without any stabilizing agents and free from agglomeration are very critical for their function and diverse catalytic applications. With the goal to accomplish a molecularly defined Pd-based heterogeneous C-C bond form
- Elavarasan,Baskar,Senthil,Bhanja, Piyali,Bhaumik,Selvam,Sasidharan
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Read Online
- Use of Imidazo[1,5-a]pyridin-3-ylidene as a Platform for Metal-Imidazole Cooperative Catalysis: Silver-Catalyzed Cyclization of Alkyne-Tethered Carboxylic Acids
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Silver complexes with 5-(4-(tert-butyl)-1H-imidazol-1-yl)-imidazo[1,5-a]pyridin-3-ylidene ligands were synthesized as metal-imidazole acid-base cooperative catalysts. Single crystal XRD analysis revealed that the silver atom was located in the vicinity of
- Rawat, Vishal Kumar,Higashida, Kosuke,Sawamura, Masaya
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supporting information
p. 1631 - 1637
(2021/02/03)
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- Fe(III)-Catalyzed, Cyclizative Coupling between 2-Alkynylbenzoates and Carbinols: Rapid Generation of Polycyclic Isocoumarins and Phthalides and Mechanistic Study
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FeCl3 catalyzed, highly regioselective cyclizative coupling of internal alkynes with alcohols has been reported for the rapid synthesis of structurally divergent, complex isocoumarins and phthalides respectively in intermolecular and intramolecular fashion. This strategy exhibited very high substrate scope and efficiency and proceeds through the simultaneous formation of C?O and C?C bonds. Observations from a series of control experiments supported a) the mechanism as Lewis acid catalyzed dual activation of ester and alcohol, b) the role of carbocation for the enhanced rates of cyclization, i. e., activation of alkyne by carbocation, and c) no role of HCl in the reported cascade process. (Figure presented.).
- Gandhi, Soniya,Baire, Beeraiah
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p. 2651 - 2657
(2020/05/25)
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- Iridium-Catalyzed Cycloisomerization of Alkynoic Acids: Synthesis of Unsaturated Lactones
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The iridium-catalyzed cycloisomerization of various alkynoic acids was successfully developed, and a series of five-, six-, and especially seven-membered unsaturated lactones were constructed with moderate yields and excellent regioselectivities (up to 68
- Huang, Yi,Zhang, Xianghe,Dong, Xiu-Qin,Zhang, Xumu
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p. 782 - 788
(2020/01/08)
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- Gold-catalyzed Rapid Construction of Nitrogen-containing Heterocyclic Compound Library with Scaffold Diversity and Molecular Complexity
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1,3-unsubstituted 2-(1H-indol-2-yl)ethanamines were employed for the first time to react with alkynoic acids (AAs) to achieve gold-catalyzed highly selective cascade reactions to furnish novel indole-fused skeletons. Furthermore, with this powerful gold catalytic system, a library of indole/pyrrole/thiophene/benzene/naphthalene/pyridine-based nitrogen-containing heterocyclic compounds (NCHCs) with scaffold diversity and molecular complexity was constructed rapidly using various amine nucleophiles (ANs) and diverse AAs as the building blocks. This general protocol features excellent selectivity, extraordinarily broad substrate scope, readily available inputs, good to high yields, high bond-forming efficiency, and step economy, thus providing a facile and efficient access to a variety of valuable nitrogen-containing heterocycles.
- Qiao, Jin,Jia, Xiuwen,Li, Pinyi,Liu, Xiaoyan,Zhao, Jingwei,Zhou, Yu,Wang, Jiang,Liu, Hong,Zhao, Fei
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- Preparation method of 3-hydroxy-2,3-dihydroisoquinoline-1,4-dione compound
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The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of a 3-hydroxy-2,3-dihydroisoquinoline-1,4-dione compound. In the preparation methodprovided by the invention, N-alkoxy-2-alkynyl benzamide
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- Green preparation method of 3-hydroxy isoindole-1-one compounds
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The invention discloses a green preparation method of 3-hydroxy isoindole-1-one compounds, and belongs to the technical field of organic synthesis. The method comprises the following steps: adopting 2-alkynyl benzamide as a reaction substrate, adding a br
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- Divergent Syntheses of (Z)-3-Alkylideneisobenzofuran-1(3 H)-ones and 1 H-Isochromen-1-ones by Copper-Catalyzed Cycloisomerization of 2-Alkynylbenzoic Acids in Ionic Liquids
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The cycloisomerization of readily available 2-alkynylbenzoic acids 1 in ionic liquids (ILs) as recyclable reaction media has been studied under the catalytic action of CuCl2. With substrates bearing an aryl group on the triple bond, a mixture o
- Mancuso, Raffaella,Pomelli, Christian S.,Chiappetta, Piera,Gioia, Katia F.,Maner, Asif,Marino, Nadia,Veltri, Lucia,Chiappe, Cinzia,Gabriele, Bartolo
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p. 6673 - 6680
(2018/06/01)
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- Boron Trichloride-Mediated Synthesis of Indoles via the Aminoboration of Alkynes
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We describe an efficient catalyst- and metal-free aminoboration of alkynes to 3-borylated indoles using one of the least expensive boron sources, BCl3. The major dichloro(indolyl)borane products can be used for the in situ construction of usefu
- Lv, Jiahang,Zhao, Binlin,Liu, Li,Han, Ying,Yuan, Yu,Shi, Zhuangzhi
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p. 4054 - 4059
(2018/09/25)
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- Stoichiometric and Catalytic C?C and C?H Bond Formation with B(C6F5)3 via Cationic Intermediates
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This work showcases a new catalytic cyclization reaction using a highly Lewis acidic borane with concomitant C?H or C?C bond formation. The activation of alkyne-containing substrates with B(C6F5)3 enabled the first catalytic intramolecular cyclizations of carboxylic acid substrates using this Lewis acid. In addition, intramolecular cyclizations of esters enable C?C bond formation as catalytic B(C6F5)3 can be used to effect formal 1,5-alkyl migrations from the ester functional groups to unsaturated carbon–carbon frameworks. This metal-free method was used for the catalytic formation of complex dihydropyrones and isocoumarins in very good yields under relatively mild conditions with excellent atom efficiency.
- Soltani, Yashar,Wilkins, Lewis C.,Melen, Rebecca L.
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p. 11995 - 11999
(2017/09/20)
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- Tetraalkynylstannanes in the Stille cross coupling reaction: a new effective approach to arylalkynes
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The Stille-type cross coupling reaction with tetraalkynylstannanes was studied in detail for the first time. The reaction provides a simple and effective route towards a variety of arylalkynes. The advantages and limitations of the proposed procedure are discussed.
- Levashov, Andrey S.,Buryi, Dmitrii S.,Goncharova, Olga V.,Konshin, Valeriy V.,Dotsenko, Victor V.,Andreev, Alexey A.
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supporting information
p. 2910 - 2918
(2017/04/14)
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- Divergent syntheses of iodinated isobenzofuranones and isochromenones by iodolactonization of 2-alkynylbenzoic acids in ionic liquids
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The regiochemical outcome of the iodolactonization of 2-alkynylbenzoic acids, carried out at 100 °C in ionic liquids (ILs) as unconventional solvents and with molecular iodine as the iodine source, in the absence of external bases, was found to be strongl
- Mancuso, Raffaella,Pomelli, Christian C.,Malafronte, Francesco,Maner, Asif,Marino, Nadia,Chiappe, Cinzia,Gabriele, Bartolo
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p. 4831 - 4841
(2017/07/10)
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- Surface-exposed Pd nanoparticles supported over nanoporous carbon hollow tubes as an efficient heterogeneous catalyst for the C[sbnd]C bond formation and hydrogenation reactions
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Designing uniformly dispersed Pd nanoparticles over nanoporous carbon supports is very demanding in the context of heterogeneous catalysis. However in most of the cases cluster/agglomerated Pd particles are formed over carbon matrixes, which lack sufficient stability and formation of a sustainable passive layer that can prevent the direct contact between the active metal sites with the reactants. Herein we report the in-situ preparation of surface-exposed Pd nanoparticle over N-doped carbon hollow tubes i.e. Pd@CHT, which showed high catalytic activity compared with agglomerated Pd on carbon. The simplicity in the preparation of Pd@CHT via one step direct carbonization of hypercrosslinked polymer tubes followed by reduction in the presence of NaBH4 can offer huge potential in liquid phase heterogeneous catalysis. High dispersibility of the catalyst in the reaction medium, good stability and reusability of Pd@CHT is observed for the Sonogashira, cyanation and hydrogenation reactions for the synthesis of a wide range of value added fine chemicals, suggesting its future potential in heterogeneous catalysis.
- Modak, Arindam,Bhaumik, Asim
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p. 147 - 156
(2016/10/30)
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- PhI(OCOCF3)2-Mediated Cyclization of o -(1-Alkynyl)benzamides: Metal-Free Synthesis of 3-Hydroxy-2,3-dihydroisoquinoline-1,4-dione
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The synthesis of an undocumented skeleton of 3-hydroxy-2,3-dihydroisoquinoline-1,4-diones has been discovered and reported. The reaction consists of an intramolecular cyclization of o-(1-alkynyl)benzamides in MeCN/H2O, mediated by metal-free, h
- Yang, Chao,Zhang, Xiang,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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p. 5320 - 5328
(2015/05/27)
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- Synthesis of isocoumarins: Rhenium complex-catalyzed cyclization of 2-ethynylbenzoic acids
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When 2-ethynylbenzoic acids were treated with a catalytic amount of a rhenium complex, such as ReCl(CO)5, 6-endo cyclization of 2-ethynylbenzoic acids proceeded with a high selectivity to give the corresponding isocoumarins in moderate to good yields.
- Umeda, Rui,Yoshikawa, Shunya,Yamashita, Kouji,Nishiyama, Yutaka
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p. 2172 - 2179
(2015/12/12)
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- On homogeneous gold/palladium catalytic systems
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Two substrates containing an aryl iodide and an allenoate ester were prepared and the goldinduced cycloisomerisation to vinylgold(I) species and their proto-deauration as well as the intramolecular palladium-catalysed cross-coupling reactions were investigated. Switching to catalytic amounts of gold and palladium and stoichiometric amounts of silver did indeed furnish the product of a cycloisomerisation/ intramolecular cross-coupling. Control experiments revealed that silver cannot substitute for gold or palladium in these reactions, but a different palladium catalyst in a different oxidation state also afforded the cycloisomerisation/intramolecular crosscoupling products in only slightly reduced yields. By ICP analysis the palladium was shown to contain gold only at the sub-ppm level. This shows how carefully results obtained with such systems have to be interpreted. Then a series of allylic and benzylic o-alkynylbenzoates were investigated in gold-and palladium-catalysed reactions. For esters of benzyl alcohol and cinnamyl alcohol no palladium co-catalyst was needed for the conversion. All reagents were thoroughly checked for palladium traces by ICP analysis in order to thoroughly exclude a gold/palladium cocatalysis. Optimisation of the gold complex, counter ion and solvent showed that gold(I) isonitrile precatalysts and silver triflate as activator in dioxane are suitable to convert a number of substrates with aryl, alkyl and even cyclopropyl substituents. Crossover experiments proved an intermolecular allyl transfer.
- Hashmi, A. Stephen K.,Lothschuetz, Christian,Doepp, Rene,Ackermann, Martin,De Buck Becker, Janosc,Rudolph, Matthias,Scholz, Christian,Rominger, Frank
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supporting information; experimental part
p. 133 - 147
(2012/04/10)
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- Pd-grafted periodic mesoporous organosilica: An efficient heterogeneous catalyst for Hiyama and Sonogashira couplings, and cyanation reactions
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The high surface area of 2D-hexagonal periodic mesoporous organosilica (PMO) containing a phloroglucinol-diimine moiety inside the pore wall has been utilized for grafting Pd(ii) at the surface of the mesopores. This Pd-containing PMO material (Pd-LHMS-3) shows excellent catalytic activity in fluoride-free Hiyama cross-coupling reactions in water at alkaline pH conditions. Sonogashira cross-couplings between terminal alkynes and aryl halides take place in the presence of water and hexamine as base in the absence of any Cu co-catalyst. Cyanation of aryl halides is equally promoted with K4[Fe(CN) 6] as the cyanide source (in the absence of poisonous KCN, NaCN or Zn(CN)2) over Pd-LHMS-3. Excellent yield of the products, reusability and the facile work-up could make this Pd-grafted PMO material a unique catalyst for the synthesis of substituted benzonitriles, unsymmetrical biphenyls and di-substituted alkynes under environmentally benign reaction conditions. Further good yield of products and no evidence of leached Pd from the catalyst surface during the reaction and its smooth recovery confirm the true heterogeneity in these catalytic reactions.
- Modak, Arindam,Mondal, John,Bhaumik, Asim
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p. 2840 - 2855
(2012/11/07)
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- NHC-catalyzed oxidative cyclization reactions of 2-alkynylbenzaldehydes under aerobic conditions: Synthesis of O-Heterocycles
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Chemical equations presented. An NHC-catalyzed, regio- and stereoselective oxidative cyclization of o-alkynylbenzaldehydes bearing an unactivated alkyne moiety as an internal electrophile has been developed to afford phthalides and isocoumarins. A single organocatalytic system enabled two sequential C-O bond formations to take place in an atom economical manner via highly efficient dual activation. Molecular oxygen in air could be utilized as a source of an oxygen atom for the oxidation of aldehydes to the corresponding benzoic acids under our newly developed reagent system.
- Park, Jong Hyub,Bhilare, Sachin V.,Youn, So Won
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p. 2228 - 2231
(2011/07/09)
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- Exploratory studies on the reaction between iodoarenes and acetylenes: One-pot, Pd-[Bmim][BF4] catalyzed preparation of trianisylethylene
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The reaction between iodoarenes and acetylenes mediated by palladium was studied, showing selectivity changes based on the nature of the substituent. A new, phosphine-, copper-, and amine-free methodology was developed, in which the synthesis of trianisylethylene from 4-iodoanisole and trimethylsilylacetylene was promoted presumably by an N-heterocyclic-carbene derived from an ionic liquid and a palladium salt, using ethanol as the hydrogen source. Graphical Abstract: [Figure not available: see fulltext.]
- Barros, Jose C.,Souza, Andrea L. F.,Da Silva, Joaquim F. M.,Antunes
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scheme or table
p. 549 - 553
(2012/01/13)
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- One-pot synthesis of phthalides via regioselective intramolecular cyclization from ortho-alkynylbenzaldehydes
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A one-pot synthesis of phthalides via an intramolecular 5-exo-dig cyclization of ortho-alkynylbenzaldehydes under mild NaClO2 oxidation conditions is described.
- Li, Jim,Chin, Elbert,Lui, Alfred S.,Chen, Lijing
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scheme or table
p. 5937 - 5939
(2010/11/21)
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- Catalyzed catalysis using carbophilic Lewis acidic gold and Lewis basic palladium: Synthesis of substituted butenolides and isocoumarins
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(Figure Presented) A new strategy for gold and palladium dual-catalytic reactivity and turnover, called catalyzed catalysis, enhanced the synthetic usefulness of vinylgold intermediates by providing dual-catalytic carbon-carbon cross-coupling as an alternative to protodemetalation. This protocol enabled the synthesis of substituted butenolides and isocoumarins from allyl esters. Kinetic and spectroscopic experiments support a mechanism in which the Lewis acidic gold complex catalyzes both an initial rearrangement step and a subsequent Lewis basic palladium oxidative-addition step.
- Shi, Yili,Roth, Katrina E.,Ramgren, Stephen D.,Blum, Suzanne A.
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supporting information; experimental part
p. 18022 - 18023
(2010/03/26)
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- InBr3-promoted divergent approach to polysubstituted indoles and quinolines from 2-ethynylanilines: Switch from an intramolecular cyclization to an intermolecular dimerization by a type of terminal substituent group
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(Chemical Equation Presented) Use of a 2-ethynylaniline having an alkyl or aryl group on the terminal alkyne selectively produced a variety of polyfunctionalized indole derivatives in moderate to excellent yields via indium-catalyzed intramolecular cyclization of the corresponding alkynylaniline. In contrast, employment of a substrate with a trimethylsilyl group or with no substituent group on the terminal triple bond, exclusively afforded polysubstituted quinoline derivatives in good yields via indium-promoted intermolecular dimerization of the ethynylaniline. This indium catalytic system successfully accommodated the intramolecular cyclization of other arylalkyne skeletons involving a carboxylic acid and an amide group.
- Sakai, Norio,Annaka, Kimiyoshi,Fujita, Akiko,Sato, Asuka,Konakahara, Takeo
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p. 4160 - 4165
(2008/09/21)
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- Cycloisomerization of γ- and δ-acetylenic acids catalyzed by gold(I) chloride
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We have developed a gold(I)-catalyzed intramolecular cyclization of γ- and δ-alkyne acids in mild conditions yielding various alkylidene lactones. Whereas a slight electronic effect of the R group was observed on the regioselectivity, bulky substituents o
- Marchal, Estelle,Uriac, Philippe,Legouin, Béatrice,Toupet, Lo?c,Weghe, Pierre van de
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p. 9979 - 9990
(2008/02/13)
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- New procedures for the selective synthesis of 2(2H)-pyranone derivatives and 3-aryl-4-iodoisocoumarins
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5-Iodo-2(2H)-pyranone derivatives have been selectively synthesized by reaction of stereodefined methyl 2-en-4-ynoates with iodine in MeCN, CH2Cl2 or C6H6 at 20°C (Method C) or by treatment of these esters with
- Biagetti, Matteo,Bellina, Fabio,Carpita, Adriano,Stabile, Paolo,Rossi, Renzo
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p. 5023 - 5038
(2007/10/03)
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- Synthesis of 6H-indolo[2,3-b][1,6]naphthyridines and related compounds as the 5-aza analogues of ellipticine alkaloids
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Treatment of 2-(1-alkynyl)phenyl isocyanates 6 with the iminophosphorane 14 produced in situ the benzoenynyl carbodiimides 15. Thermolysis of 15 under refluxing p-xylene furnished the 6H-indolo[2,3-b][1,6]naphthyridines 5, which could be regarded as the 5-aza analogues of ellipticine alkaloids. Similarly, condensation of 6 with the iminophosphorane 20 led to the formation of the 6H-indolo[2,3-b][1,5]naphthyridines 25 as the major isomer and the 10H-indolo[2,3-b][1,7]naphthyridines 26 as the minor isomer. The indolonaphthyridines 32, 33, and 34 having a methoxyl substituent were likewise synthesized. Treatment of the diisocyanate 43 with 2 equiv of the iminophosphorane 7 furnished 45 having two indoloquinoline units incorporated in a seven-fused-ring system.
- Zhang,Shi,Zhang,Wang
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p. 7977 - 7983
(2007/10/03)
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- Biradicals from thermolysis of N-[2-(1-alkynyl)phenyl]-N'- phenylcarbodiimides and their subsequent transformations to 6H-indolo[2,3- b]quinolines
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Thermolysis of the carbodiimide 9a in γ-terpinene at 138 °C produced 2-(phenylamino)quinoline (11a, 49%) and the parent 6H-indolo[2,3-b]quinoline (14a, 16%). Apparently, 11a was produced via the biradical 10a followed by hydrogen-atom abstraction from γ-terpinene. A two-step biradical pathway through 12a or a one-step intramolecular Diels-Alder reaction could furnish 13a, which then underwent tautomerization to give 14a. With the carbodiimide 9b having a trimethylsilyl substituent at the acetylenic terminus, thermolysis in refluxing p-xylene at 138 °C produced the 6H-indolo[2,3- b]quinoline 14b (86%) exclusively. Treatment of 14b with 6 N NaOH in refluxing ethanol then furnished 14a in 92% yield. Similarly, the 6H- indolo[2,3-b]quinolines 14c-f were obtained from thermolysis of the carbodiimides 9c-f. The use of the aza-Wittig reaction between 4- methoxyphenyl isocyanate and the iminophosphoranes 2d and 2f to produce the corresponding carbodiimides followed by thermolysis furnished the 6H- indolo[2,3-b]quinolines 16d and 16f having a methoxy substituent at the C-2 position. Thermolysis of the carbodiimides 25a and 25b produced 26a and 26b having two indoloquinoline units connected at the 11 and 11' positions with either a three-carbon or a five-carbon tether. Using 1,4-phenylene diisocyanate for the aza-Wittig reaction with 2 equiv of the iminophosphorane 2g followed by thermolysis furnished 31 (66%) having two indoloquinoline units incorporated in the seven fused rings.
- Shi, Chongsheng,Zhang, Quan,Wang, Kung K.
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p. 925 - 932
(2007/10/03)
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- An Efficient Stereospecific Preparation of (Z)-3-Methylidene-selenophthalides and (Z)-3-Methylidenetellurophthalides [1]
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(Z)-3-Methylideneselenophthalides 5A and (Z)-3-methylidenetellurophthalides 5B were easily prepared by the regioselective and stereoselective reaction of 2-ethynylbenzoyl chlorides 3 with sodium hydroselenide and sodium hydrotelluride in good yields, resp
- Sashida, Haruki,Kawamukai, Atsushi
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p. 165 - 167
(2007/10/03)
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- Palladium-catalysed heteroannulation with terminal alkynes: Synthesis of phthalides
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The palladium-copper-catalysed heteroannulation of o-iodobenzoic acid 3 with terminal alkynes 4-18 leads to the synthesis of (Z)-3-alkylidenephthalides 19-33 as the major products. In certain cases, the formation of isocoumarins 34-37 is also observed.
- Kundu, Nitya G.,Pal, Manojit,Nandi, Bidisha
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p. 561 - 568
(2007/10/03)
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- Transmission of Polar Effects. Part 21. Alkaline Hydrolysis of the 2'- and 4'-substituted 2-Methoxycarbonyldiphenylacetylenes and (Z)-2'- and -4'- Substituted 2-Methoxycarbonylstilbenes and the Ionisation and Esterification, with Diazodiphenylmethane of t
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The rate coefficients for the alkaline hydrolysis of a series of 2'- and 4'-substituted 2-methoxycarbonyldiphenylacetylenes and (Z)-2-methoxycarbonylstilbenes have been determined in 70percent (v/v) dimethyl sulphoxide-water at both 30.0 and 50.0 deg C an
- Bowden, Keith,Ghadir, Khalaf D. F.
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p. 1333 - 1338
(2007/10/02)
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