- Heteroaryl functionalised diacetylenes: Preparation and solid-state reactivity
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Diacetylenes are known to undergo solid-state topochemical polymerisation to give polydiacetylenes. The reactivity of the monomer is controlled by the arrangement of the molecules in the crystal lattice wherein certain parametric conditions must be met for 1,4-addition to proceed. In the present paper, we investigated the structure-reactivity relationship of a class of diacetylene monomers. Heteroaryl moieties such as thiophene, benzo[b]thiophene and quinoline as one or both directly bound side groups of a diacetylene backbone were used. Thus various symmetrical as well as unsymmetrical diacetylenes were prepared and characterised. The solid-state polymerisation behaviour of these diacetylenes was studied in the light of their single-crystal X-ray structure. It was found that in order to react in the solid state, the diacetylenes must have the required lattice parameters. However, even when the required lattice parameters are met, the diacetylene monomers do not necessarily undergo solid-state 1,4-addition polymerisation, implying the existence of further controlling factors to determine reactivity.
- Sarkar, Abhijit,Talwar, Satya S.
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- An improved procedure for the preparation of aryl- and hetarylacetylenes
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A number of relatively volatile acetylenes RC ≡ CH (R = aryl or hetaryl) have been prepared with high yields by heating a mixture of the corresponding alcohols RC ≡ CC(CH3)2OH and paraffin oil with small amounts of powdered potassium hydroxide in vacuum. The alcohols were obtained by Pd/Cu-catalyzed cross coupling of aryl or hetaryl halides RX (X = Br, in one case I) with the commercially available HC ≡ CC(CH3)2OH.
- Mal'Kina,Brandsma,Vasilevsky,Trofimov
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- Thermal behavior of diynes with formally conjugated heteroaromatic sidegroups
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Diynes with heteroaromatic sidegroups directly linked to the acetylenic backbone were found to show liquid crystalline behaviour upon heating. Thus, 1,4-di(2-thienyl)-1,3-butadiyne, 1,4-di(3-thienyl)-1,3-butadiyne, 1,4-di(3- benzo[b]thienyl)-1,3-butadiyne, 1-(3-quinolyl)-4-(2-thienyl)-1,3-butadiyne, 1-(3-quinolyl)-4-(3-thienyl)-1,3-butadiyne, and 5-(2-thienyl)-2,4-pentadiyne- 1-ol were investigated for their thermal behavior. These diynes also underwent polymerization in their liquid crystalline state, although the polymers so formed did not show liquid crystalline behavior. It was found that the S-atom of the heteroaromatic moieties tends to play a role in making the diynes show liquid crystalline behavior. Differential scanning calorimetry, thermogravimetric analysis and hot stage microscopy were used to investigate the liquid crystalline nature of the diynes. All of them showed a nematic liquid crystalline phase upon annealing, whereas smectic phase was totally absent.
- Sarkar, Abhijit,Talwar, Satya S.
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- Nanosized Pd(0)-arabinogalactan composites as catalysts in the Sonogashira reaction
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Zero-valent palladium nanoparticles stabilized by arabinogalactan polysaccharide matrix were successfully used for the first time as phosphine-free catalyst in the cross-coupling of terminal alkynes with aryl and hetaryl halides.
- Parshina,Tantsyrev,Grishchenko,Trofimov
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- Facile synthesis of substituted thiophenes via Pd/C-mediated sonogashira coupling in water
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The first successful Pd/C-mediated Sonogashira coupling of iodothiophene with terminal alkynes in water is described here. Pd/C-CuI-PPh3 was found to be an efficient catalyst system for this coupling reaction. Using this economic and reliable process a variety of acetylenic thiophenes with a wide range of functional groups were prepared in good yields. Synthetic applications and in vitro anticancer properties of some of the compounds synthesized are described.
- Raju, Sirisilla,Kumar, P. Rajender,Mukkanti,Annamalai, Pazhanimuthu,Pal, Manojit
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- Rhodium-catalyzed oxidative coupling of benzoic acids with propargyl alcohols: An efficient access to isocoumarins
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An efficient protocol of Rh(III)-catalyzed oxidative cyclization of benzoic acids with propargyl alcohols to give substituted isocoumarins under mild conditions was reported. A variety of substrates were applied in this reaction in yields up to 89%.
- Luo, Feihua,He, Shuhua,Gou, Quan,Chen, Jinyang,Zhang, mingzhong
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- Bimetal Cooperatively Catalyzed Arylalkynylation of Alkynylsilanes
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An unprecedented Pd/Rh cooperatively catalyzed arylalkynylation of alkynylsilanes was developed to merge an alkynylidene moiety with benzosilacycle. These silaarenes possess a particular aggregation-induced emission behavior. Mechanistic investigations demonstrate that the relay trimetallic transmetalation plays a pivotal role in governing this transformation.
- Chen, Xing,Li, Mengke,Liu, Zhipeng,Yang, Can,Xie, Haisheng,Hu, Xinwei,Su, Shi-Jian,Jiang, Huanfeng,Zeng, Wei
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supporting information
p. 6724 - 6728
(2021/09/08)
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- Cleavage of C–C and C–O Bonds to Form C–C Bonds: Direct Cross-Coupling between Acetylenic Alcohols and Benzylic Carbonates
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A palladium-catalyzed cross-coupling reaction between C(sp) and C(sp3) centers was achieved in excellent yields via C–C bond cleavage and C–O bond cleavage. This procedure uses relatively stable acetylenic alcohols as reactants instead of unsta
- Mi, Zhiyuan,Tang, Jiahao,Guan, Zhipeng,Shi, Wei,Chen, Hao
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supporting information
p. 4479 - 4482
(2018/09/10)
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- Highly Efficient Synthesis of Multi-Substituted Allenes from Propargyl Acetates and Organoaluminum Reagents Mediated by Palladium
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A simple and mild catalytic S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents is reported. The S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents mediated by Pd(PhP 3) 2 Cl 2 (1 mol%)/PPh 3 (2 mol%)/K 2 CO 3 in tetrahydrofuran at 60 °C for 3-4 hours afforded the corresponding multi-substituted allenes in good yields (up to 94%) with high selectivities (up to 99%). The process was simple and easily performed, which offers an efficient method to synthesize the multi-substituted allene derivatives.
- Zhang, Zhen,Shao, Xuebei,Zhang, Gang,Li, Qinghan,Li, Xinying
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p. 3643 - 3653
(2017/08/16)
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- Gold-Catalyzed [4+2]- and [3+3]-Annulations of Ynamides with 1-Yn-3-ols to Access Six-Membered Carbocycles and Oxacycles via Three Distinct Cyclizations
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Three distinct strategies for catalytic annulations between ynamides and 1-yn-3-ols are described; the resulting carbo- and heterocycles were produced efficiently in one-pot operations using a gold catalyst. The chemoselectivities of these annulations are controlled by variations of the substituents of the ynamides and the 1-yn-3-ols. This reaction sequence involves initial alkoxylations of ynamides, followed by Claisen rearrangement of propargylic enol ethers, and ends with 6-endo-trig cyclizations of 1-allenyl-5-amide intermediates. Among these cascade annulations, the cyclizations of 5-allenyl-1-amides to yield 5,6-dihydro-2-pyranones and 6-alkylenecyclohex-2-ene-1-carboxamides are unprecedented in the literature. (Figure presented.).
- Giri, Sovan Sundar,Liu, Rai-Shung
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supporting information
p. 3311 - 3318
(2017/09/13)
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- Efficient Microwave-Assisted Synthesis of Sonogashira-Coupled Perylene Monoimide Derivatives: Impact of Electron-Donating Groups on Optoelectronic Properties
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An efficient microwave-assisted Sonogashira-coupling protocol for the synthesis of peri-functionalized perylene monoimide dye derivatives was developed. This method was found to be significantly faster than the conventional coupling method and provided pr
- Sharma, Vikas,Chandra, Falguni,Sahoo, Dhananjaya,Koner, Apurba L.
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supporting information
p. 6901 - 6905
(2017/12/26)
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- Palladium-Catalyzed Nitration of Meyer-Schuster Intermediates with tBuONO as Nitrogen Source at Ambient Temperature
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A novel domino palladium-catalyzed nitration of Meyer-Schuster intermediates which were generated in situ from propargylic alcohols was developed, by the use of t-BuONO, leading to α-nitro enones in good to excellent yields at room temperature with a broa
- Lin, Yuanguang,Kong, Weiguang,Song, Qiuling
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supporting information
p. 3702 - 3705
(2016/08/16)
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- Synthesis of Oxazolidin-2-ones by Tandem Cyclization of Propargylic Alcohols and Phenyl Isocyanate Promoted by Silver Catalysts as π-Lewis Acids
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Highly Z-selective syntheses of oxazolidin-2-ones from propargylic alcohols containing internal alkynes and phenyl isocyanate were achieved by using a combination of silver acetate and N,N-dimethylaminopyridine. The catalytic system was applied to proparg
- Sekine, Kohei,Mawatari, Takanori,Yamada, Tohru
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supporting information
p. 2447 - 2450
(2015/10/19)
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- Cyclization of Diaryl(hetaryl)alkynes under Selenobromination Conditions: Regioselectivity and Mechanistic Studies
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The cyclization of substituted diaryl(hetaryl)alkynes with in-situ-prepared SeBr4 has been achieved. The use of an alkene additive as a bromine scavenger gives simple access to functionalized benzo[b]selenophene and selenophenothiophene derivatives from commercially available or easily accessible starting materials. The reactions can be performed in air without the use of moisture-sensitive reagents, dry solvents, or an inert atmosphere. Mechanistic studies confirmed a regioselective anti 1,2-addition in the selenobromination step, and a subsequent electrophilic substitution in the aromatic ring to complete the cyclization. The cyclization of substituted diaryl(hetaryl)alkynes with in-situ-prepared SeBr4 has been achieved. The use of an alkene additive as a bromine scavenger gives simple access to functionalized benzo[b]selenophene and selenophenothiophene derivatives from commercially available or easily accessible starting materials.
- Paegle, Edgars,Belyakov, Sergey,Petrova, Marina,Liepinsh, Edvards,Arsenyan, Pavel
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supporting information
p. 4389 - 4399
(2015/07/27)
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- An approach to the selenobromination of aryl(thienyl)alkynes: Access to 3-bromobenzo[b]selenophenes and selenophenothiophenes
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A novel approach for the cyclization of arylalkynes with selenium(IV) bromide prepared in situ has been elaborated. The use of an alkene additive as a bromine scavenger provides a convenient synthetic pathway for the synthesis of a wide variety of 3-bromobenzo[b]selenophenes. Reactions can be performed open to air without the use of moisture-sensitive reagents, anhydrous solvents, or an inert atmosphere. Selenobromination of ethynylthiophenes has been applied for the preparation of selenopheno[3,2-b]- and selenopheno[2,3-b]thiophenes. The molecular structures of representative derivatives have been confirmed by X-ray crystallographic analysis. The use of an alkene additive as a bromine scavenger under selenobromination conditions provides a convenient synthetic pathway for the synthesis of a wide variety of 3-bromobenzo[b]selenophenes in moderate to high yields. The reactions are not moisture-sensitive and do not require an inert atmosphere. Selenobromination of ethynylthiophenes enables the preparation of selenopheno[b]thiophenes. Copyright
- Paegle, Edgars,Belyakov, Sergey,Arsenyan, Pavel
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supporting information
p. 3831 - 3840
(2014/06/24)
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- A copper-free, cross-coupling of terminal alkynes with hetaryl halides
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Substituted ethynyl heterocycles and heteroarylbutenynes are synthesized efficiently in good yields via a copper-free, cross-coupling reaction.
- Arsenyan, Pavel,Rubina, Kira,Vasiljeva, Jelena,Belyakov, Sergey
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p. 6524 - 6528
(2013/11/19)
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- Sonogashira reaction of aryl and heteroaryl halides with terminal alkynes catalyzed by a highly efficient and recyclable nanosized MCM-41 anchored palladium bipyridyl complex
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A heterogeneous catalyst, nanosized MCM-41-Pd, was used to catalyze the Sonogashira coupling of aryl and heteroaryl halides with terminal alkynes in the presence of CuI and triphenylphosphine. The coupling products were obtained in high yields using low Pd loadings to 0.01 mol%, and the nanosized MCM-41-Pd catalyst was recovered by centrifugation of the reaction solution and re-used in further runs without significant loss of reactivity.
- Lin, Bo-Nan,Huang, Shao-Hsien,Wu, Wei-Yi,Mou, Chung-Yuan,Tsai, Fu-Yu
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experimental part
p. 9157 - 9173
(2011/02/27)
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- High throughput evaluation of the production of substituted acetylenes by the Sonogashira reaction followed by the Mizoroki-Heck reaction in ionic liquids, in situ, using a novel array reactor
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The parallel Sonogashira coupling reaction was carried out under copper-free condition by integrating the advantages of ionic liquids as the reaction media followed by the simultaneous-multiple Mizoroki-Heck reaction in situ by the use of a novel array re
- Rahman, Md. Taifur,Fukuyama, Takahide,Ryu, Ilhyong,Suzuki, Kanae,Yonemura, Koichi,Hughes, Philip F.,Nokihara, Kiyoshi
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p. 2703 - 2706
(2007/10/03)
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- Design and preparation of 2-benzamido-pyrimidines as inhibitors of IKK
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The design, synthesis, and the biological evaluation of 2-benzamido-pyrimidines as novel IKK inhibitors are described. By optimization of the lead compound 3, compounds 16 and 24 are identified as good inhibitors of IKK2 with IC50 values of 40 and 25 nM, respectively. Compound 16 also demonstrated significant in vivo activity in an acute model of cytokine release.
- Waelchli, Rudolf,Bollbuck, Birgit,Bruns, Christian,Buhl, Thomas,Eder, Joerg,Feifel, Roland,Hersperger, Rene,Janser, Philipp,Revesz, Laszlo,Zerwes, Hans-Guenter,Schlapbach, Achim
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p. 108 - 112
(2007/10/03)
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- Sonogashira cross-coupling reaction of organotellurium dichlorides with terminal alkynes
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The Sonogashira cross-coupling reaction of vinylic and heteroaromatic tellurium dichlorides has been explored, yielding the corresponding enynes and 2-alkynyl substituted heteroaromatic compounds. The reaction was carried out with PdCl2/CuI as catalysts and triethylamine as base, using methanol as solvent. The reaction proceeded under mild conditions and the cross-coupled products were obtained in good yields and in a stereoconservative manner.
- Braga, Antonio L.,Lüdtke, Diogo S.,Vargas, Fabrício,Donato, Ricardo K.,Silveira, Claudio C.,Stefani, Hélio A.,Zeni, Gilson
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p. 1779 - 1781
(2007/10/03)
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- Sonogashira coupling using bulky palladium-phenanthryl imidazolium carbene catalysis
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(Matrix presented) Bulky phenanthracenyl imidazolium-derived carbene ligands were investigated for copper-free Sonogashira coupling with terminal acetylenes. Aryl bromides and iodides gave coupled products in excellent yields from the Pd(PPh3)2Cl2 complex with potassium t-butoxide and 18-crown-6 in THF. A remarkable dependence on the size of the ligand was found. The highest yields were obtained with the bulky 2,9-dicyclohexyl-10-phenanthryl ligand 5.
- Ma, Yudao,Song, Chun,Jiang, Wei,Wu, Quansheng,Wang, Yong,Liu, Xueying,Andrus, Merritt B.
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p. 3317 - 3319
(2007/10/03)
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- Copper-catalyzed coupling reaction of terminal alkynes with aryl- and alkenyliodonium salts
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(Equation presented) The copper iodide-catalyzed cross-coupling of terminal alkynes with hypervalent iodonium salts was accomplished with Cul (10 mol %) and NaHCO3 (2 equiv) in DME/H2O (4:1) at room temperature for 30 min to afford arylalkynes or enynes under mild conditions.
- Kang, Suk-Ku,Yoon, Seok-Keun,Kim, Young-Mook
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p. 2697 - 2699
(2007/10/03)
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