- Synthesis of Diarylethynes from Aryldiazonium Salts by Using Calcium Carbide as an Alkyne Source in a Deep Eutectic Solvent
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An efficient method for the synthesis of diarylethynes from aryldiazonium salts by using calcium carbide as an alkyne source at room temperature in a deep eutectic solvent is described. The salient features of this protocol are an inexpensive and easy-to-handle alkyne source, a nonvolatile and recyclable solvent, mild conditions, and a simple workup procedure.
- Ma, Xiaolong,Li, Zheng
-
supporting information
p. 631 - 635
(2020/12/28)
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- Iodonium Cation-Pool Electrolysis for the Three-Component Synthesis of 1,3-Oxazoles
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The synthesis of 1,3-oxazoles from symmetrical and unsymmetrical alkynes was realized by an iodonium cation-pool electrolysis of I2 in acetonitrile with a well-defined water content. Mechanistic investigations suggest that the alkyne reacts with the acetonitrile-stabilized I+ ions, followed by a Ritter-type reaction of the solvent to a nitrilium ion, which is then attacked by water. The ring closure to the 1,3-oxazoles released molecular iodine, which was visible by the naked eye. Also, some unsymmetrical internal alkynes were tested and a regioselective formation of a single isomer was determined by two-dimensional NMR experiments.
- Sattler, Lars E.,Hilt, Gerhard
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p. 605 - 608
(2020/12/07)
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- Synthesis of α-Ketoimidoyl Fluorides via Geminal Fluorine-Promoted Azide Rearrangement
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Despite the promising synthetic potential, the utilization of imidoyl fluorides has been hampered by the lack of broadly applicable preparative methods. Herein, bench-stable α-ketoimidoyl fluorides were synthesized from geminal chlorofluorides through tandem azidation/rearrangement under mild conditions. The efficiency was consistently high, regardless of the steric and electronic environments. The synthetic utility of the α-ketoimidoyl fluoride was also demonstrated. Furthermore, the remarkable accelerating effect of the geminal fluorine substituent was identified and rationalized by density functional theory calculation.
- Kim, Ha Eun,Choi, Jun-Ho,Chung, Won-Jin
-
supporting information
p. 8810 - 8815
(2021/11/20)
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- Selective Synthesis of Non-Aromatic Five-Membered Sulfur Heterocycles from Alkynes by using a Proton Acid/N-Chlorophthalimide System
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A multicomponent strategy to achieve two different regioselectivities from alkynes, isothiocyanates and H2O with a proton acid/N-chlorophthalimide (NCPI) system is described to selectively obtain non-aromatic five-membered sulfur heterocycles (1,3-oxathiol-2-imines/thiazol-2(3H)-one derivatives) through multiple bond formations. The process features readily available starting materials, mild reaction conditions, broad substrate scope, good functional-group tolerance, high regio- and chemo- selectivities, gram-scale synthesis and late-stage modifications. Mechanistic studies support the proposal that the transformation process includes a combination of H2O and isothiocyanate, free-radical formation, carbonation and intramolecular cyclization to give the products. Furthermore, the 1,3-oxathiol-2-imine derivatives possess unique fluorescence characteristics and can be used as Pd2+ sensors with a “turn-off” response, demonstrating potential applications in environmental and biological fields.
- Yu, Wentao,Zhu, Baiyao,Shi, Fuxing,Zhou, Peiqi,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 1313 - 1322
(2020/12/01)
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- Rhodium-Catalyzed Regioselective Hydroformylation of Alkynes to α,β-Unsaturated Aldehydes Using Formic Acid
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A rhodium-catalyzed hydroformylation of alkynes with formic acid was developed. The method provides α,β-unsaturated aldehydes in high yield and E-selectivity without the need to handle toxic CO gas.
- Fan, Chao,Hou, Jing,Chen, Yu-Jia,Ding, Kui-Ling,Zhou, Qi-Lin
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supporting information
p. 2074 - 2077
(2021/04/05)
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- Selective Phosphoranation of Unactivated Alkynes with Phosphonium Cation to Achieve Isoquinoline Synthesis
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We herein develop a selective phosphoranation of alkynes with phosphonium cation, which directs a concise approach to isoquinolines from unactivated alkyne and nitrile feedstocks in a single step. Mechanistic studies suggest that the annulation reaction is initiated by the unprecedented phosphoranation of alkynes, thus representing a unique reaction pattern of phosphonium salts and distinguishing it from existing protocols that largely rely on the utilization of highly functionalized imines/oximes and/or highly polarized alkynes.
- Cui, Hong,Bai, Jinku,Ai, Tianyu,Zhan, Ye,Li, Guanzhong,Rao, Honghua
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supporting information
p. 4023 - 4028
(2021/05/26)
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- Diborative Reduction of Alkynes to 1,2-Diboryl-1,2-Dimetalloalkanes: Its Application for the Synthesis of Diverse 1,2-Bis(boronate)s
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Reduction of alkynes with alkali metals in the presence of B2pin2 results in diboration of alkynes. Distinct from conventional dissolving metal hydrogenations, two carbon-boron bonds and also two carbon-alkali metal bonds can be constructed in one operation to form 1,2-diboryl-1,2-dimetalloalkanes. The 1,2-diboryl-1,2-dimetalloalkanes generated are readily convertible to a wide range of vicinal bis(boronate)s. In particular, oxidation of the 1,2-dianionic species provides (E)-1,2-diborylalkenes, unique anti-selective diboration of alkynes being thus executed.
- Takahashi, Fumiya,Nogi, Keisuke,Sasamori, Takahiro,Yorimitsu, Hideki
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supporting information
p. 4739 - 4744
(2019/06/27)
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- Copper-Catalyzed Twofold Silylmetalation of Alkynes
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The first twofold silylmetalation across a C≡C triple bond was achieved. In the presence of a catalytic amount of copper cyanide, diarylacetylenes were converted into 1,2-dimetalated 1,2-disilyl-1,2-diarylethanes on treatment with silylpotassium species generated in situ from disilane and t -BuOK. The dimetalated species were subsequently protonated to yield a series of 1,2-disilyl-1,2-diarylethanes.
- Shimokawa, Jun,Yamagishi, Hiroki,Yorimitsu, Hideki
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supporting information
p. 1551 - 1554
(2019/08/07)
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- Rhodium(iii)-catalyzed unreactive C(sp3)-H alkenylation of N-alkyl-1H-pyrazoles with alkynes
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The first example of pyrazole-directed rhodium(iii)-catalyzed unreactive C(sp3)-H alkenylation with alkynes has been described, which showed a relatively broad substrate scope with good functional group compatibility. Moreover, we demonstrated that the transitive coordinating center pyrazole could be easily removed under mild conditions.
- Li, Tongyu,Liu, Chang,Wu, Shaonan,Chen, Chen C.,Zhu, Bolin
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supporting information
p. 7679 - 7683
(2019/08/30)
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- Electrochemistry-Enabled Ir-Catalyzed Vinylic C-H Functionalization
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Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C-H functionalization, yet this type of transformation has thus far mainly been limited to arene C-H functionalization. Herein, we report the development of electrochemical vinylic C-H functionalization of acrylic acids with alkynes. In this reaction an iridium catalyst enables C-H/O-H functionalization for alkyne annulation, affording α-pyrones with good to excellent yields in an undivided cell. Preliminary mechanistic studies show that anodic oxidation is crucial for releasing the product and regeneration of an Ir(III) intermediate from a diene-Ir(I) complex, which is a coordinatively saturated, 18-electron complex. Importantly, common chemical oxidants such as Ag(I) or Cu(II) did not give significant amounts of the desired product in the absence of electrical current under otherwise identical conditions.
- Yang, Qi-Liang,Xing, Yi-Kang,Wang, Xiang-Yang,Ma, Hong-Xing,Weng, Xin-Jun,Yang, Xiang,Guo, Hai-Ming,Mei, Tian-Sheng
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supporting information
p. 18970 - 18976
(2019/12/04)
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- Synthesis of α,α-Dichloroketones through Sequential Reaction of Decarboxylative Coupling and Chlorination
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2,2-Dichloro-1,2-diarylethanones were synthesized from diarylalkynes and trichloroisocyanuric acid. The reaction was conducted in CH3CN/H2O at room temperature for 12 h. In addition, the desired 2,2-dichloro-1,2-diarylethanones could be prepared from aryl bromides and propiolic acid through sequential Pd-catalyzed decarboxylative coupling and chlorination. This method showed moderate to good yields and good tolerance toward functional groups such as chlorides, bromides, aldehydes, and ketones.
- Cho, Eunjeong,Kim, Myungjin,Jayaraman, Aravindan,Kim, Jimin,Lee, Sunwoo
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supporting information
p. 781 - 784
(2018/02/21)
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- Palladium-catalyzed sequential three-component reactions to access vinylsilanes
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A palladium-catalyzed sequential three-component reaction has been developed. The palladacycles, generated through cascade reactions of aryl halides and alkynes, are the key intermediates and react with hexamethyldisilane to form disilylated products. The reaction represents a useful preparative method for vinylsilanes, and the vinylsilanes can be transformed into tetrasubstituted alkenes.
- Zhou, Bo,Lu, Ailan,Shao, Changdong,Liang, Xinda,Zhang, Yanghui
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p. 10598 - 10601
(2018/09/25)
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- Direct Synthesis of Symmetric Diarylethynes from Calcium Carbide and Arylboronic Acids/Esters
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A new methodology for the direct synthesis of symmetric diarylethynes from the reactions of calcium carbide with arylboronic acids/esters is described. Various symmetric diarylethynes were generated from the corresponding arylboronic acids/esters in satisfactory yield by using a palladium catalyst. The advantages of this protocol include the use of a readily available and easy-to-handle acetylene source, and a simple work-up procedure.
- Fu, Rugang,Li, Zheng
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p. 6648 - 6651
(2017/12/15)
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- Blue-shifted aggregation-induced emission of siloles by simple structural modification and their application as nitro explosive chemosensors
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To induce blue-shifted emission of siloles, two tolyl-substituted derivatives-1,1-diphenyl-2,3,4,5-tetra(m-tolyl)-1H-silole (m-TS) and 1,1-diphenyl-2,3,4,5-tetra(o-tolyl)-1H-silole (o-TS)-were prepared, and their photophysical properties were compared with those of a reference compound, hexaphenylsilole (HPS). By substituting methyl groups at ortho positions of peripheral tetraphenyl rings on the silacyclopentadiene ring, intramolecular rotations could be successfully controlled and the photophysical properties were varied, while substituting methyl groups at meta positions showed similar photophysical properties compared with the case of HPS. That is, simple structural modification at the ortho position significantly affects the geometry and the photophysical properties of silole, which leads to blue-shifted emission. Finally, two tolyl-substituted siloles and HPS were employed as chemosensors for the detection of nitro explosives, and o-TS showed the highest sensing ability.
- Lee, Jiwon,Park, Yoona,Jung, Joori,Han, Won-Sik
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p. 1495 - 1501
(2017/10/19)
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- Cp?CoIII-Catalyzed Synthesis of Pyrido[2′,1′:2,3]pyrimido[1,6-a]indol-5-iums via Tandem C-H Activation and Subsequent Annulation from 1-(Pyridin-2-yl)-1H-indoles and Internal Alkynes
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A Cp?CoIII-catalyzed C2-selective C-H alkenylation/annulation cascade transformation of 1-(pyridin-2-yl)-1H-indoles with internal alkynes to afford pyrido[2′,1′:2,3]pyrimido[1,6-a]indol-5-iums is presented. Moreover, 6,7-dihydro-4H-pyrido[2′,1′:2,3]pyrimido[1,6-a]indole, a new functionalized N-fused indole core heterocycle, could be constructed effectively via reduction of pyrido[2′,1′:2,3]pyrimido[1,6-a]indol-5-ium by NaBH4.
- Yang, Yuhan,Li, Bo,Liu, Wenmin,Zhang, Rumeng,Yu, Lintao,Ma, Qin-Ge,Lv, Rongrong,Du, Donghua,Li, Ting
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p. 11335 - 11345
(2016/11/29)
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- Palladium(II)-Catalyzed Annulation of Alkynes with 2-(Cyanomethyl)phenylboronates Leading to 3,4-Disubstituted 2-Naphthalenamines
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1,2-Bis(diphenylphosphino)ethane (dppe)-ligated palladium(II) complexes catalyze the annulation of internal alkynes with 2-(cyanomethyl)phenylboronates to provide 3,4-disubstituted-2-naphthalenamines in good yields. The annulation reaction proceeds under mild and neutral conditions and requires methanol as an essential solvent. In addition to symmetrical alkynes, unsymmetrical alkynes substituted by aryl, alkyl, and alkynyl groups participate in the annulation to afford the corresponding 2-naphthalenamines with electron-withdrawing sp2- and sp-carbons preferentially located at the C-3 position. Substituents including an alkyl or alkoxy group on the cyanomethyl moiety and a halogen atom on the benzene ring in the boronates are compatible with the reaction conditions. The annulation proceeds through the transmetalation of the palladium(II) complexes with the boronates and alkyne insertion followed by nucleophilic addition of the generated alkenylpalladium(II) species to the intramolecular cyano group. Stoichiometric reactions revealed that the methanol solvent was effective for both transmetalation and catalyst regeneration.
- Tsukamoto, Hirokazu,Ikeda, Taishi,Doi, Takayuki
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p. 1733 - 1745
(2016/03/15)
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- Palladium-Catalyzed Domino Process: Synthesis of Symmetrical Diarylalkynes, cis- and trans-Alkenes using Lithium Acetylide as a Synthon
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An efficient domino protocol has been developed for the synthesis of symmetrical diarylalkynes. Notably, the method was successful in the presence of a palladium catalyst without the support of a copper co-catalyst. Significantly, the method enabled the use of the commercially available and cheap lithium acetylide ethylenediamine complex as a source of acetylene for the construction of dual C-C bonds, with a wide range of compatibility towards various substituents of the aryl bromides/iodides. Significantly, this protocol was successfully applied to the synthesis of cis- and trans-alkenes in a highly stereoselective manner in a sequential one-pot process.
- Krishna, Jonnada,Krishna Reddy, Alavala Gopi,Satyanarayana, Gedu
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p. 3597 - 3610
(2016/01/25)
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- Application of palladium complexes bearing acyclic amino(hydrazido)carbene ligands as catalysts for copper-free Sonogashira cross-coupling
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Abstract Metal-mediated coupling of one isocyanide in cis-[PdCl2(CNR1)2] (R1 = C6H11 (Cy) 1, tBu 2, 2,6-Me2C6H3 (Xyl) 3, 2-Cl-6-MeC6H3
- Timofeeva, Svetlana A.,Kinzhalov, Mikhail A.,Valishina, Elena A.,Luzyanin, Konstantin V.,Boyarskiy, Vadim P.,Buslaeva, Tatyana M.,Haukka, Matti,Kukushkin, Vadim Yu.
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p. 449 - 456
(2015/07/15)
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- Regioselective synthesis of tetraphenyl-1,3-butadienes with aggregation-induced emission
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In the presence of substoichiometric amounts of Co2(CO)8, internal bisarylalkynes undergo reductive dimerization with good to excellent yields. The Co2(CO)8-induced reactions described are experimentally quite simple and provide a very useful synthetic procedure for the synthesis of tetraphenylbutadienes which exhibit aggregation-induced emission enhancement, i.e., weak emission in good solvents but strong fluorescence in solvents that lead toward formation of aggregates or in the solid state.
- Ezhumalai, Yamuna,Wang, Tsai-Hui,Hsu, Hsiu-Fu
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supporting information
p. 536 - 539
(2015/03/04)
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- Rhodium-Catalyzed C-H Annulation of Nitrones with Alkynes: A Regiospecific Route to Unsymmetrical 2,3-Diaryl-Substituted Indoles
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The direct C-H annulation of anilines or related compounds with internal alkynes provides straightforward access to 2,3-disubstituted indole products. However, this transformation proceeds with poor regioselectivity in the synthesis of unsymmetrically 2,3-diaryl substituted indoles. Herein, we report the rhodium(III)-catalyzed C-H annulation of nitrones with symmetrical diaryl alkynes as an alternative method to prepare 2,3-diaryl-substituted N-unprotected indoles with two different aryl groups. One of the aryl substituents is derived from N?C-aryl ring of the nitrone and the other from the alkyne substrate, thus providing the indole products with exclusive regioselectivity.
- Yan, Hao,Wang, Haolong,Li, Xincheng,Xin, Xiaoyi,Wang, Chunxiang,Wan, Boshun
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supporting information
p. 10613 - 10617
(2015/09/02)
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- Synthesis of diarylalkynes via tandem Sonogashira/decarboxylative reaction of aryl chlorides with propiolic acid
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A facile and efficient protocol for one-pot synthesis of diarylalkynes via tandem Sonogashira/decarboxylative coupling has been developed. The remarkable features of this reaction include using commercially available aryl chlorides as starting materials and taking the propiolic acid instead of expensive terminal alkynes as an acetylene source. This journal is the Partner Organisations 2014.
- Li, Xiang,Yang, Fan,Wu, Yangjie
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p. 13738 - 13741
(2014/04/03)
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- Palladium nanoparticles catalyzed Sonogashira reactions for the one-pot synthesis of symmetrical and unsymmetrical diarylacetylenes
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A variety of symmetrical and unsymmetrical diarylacetylenes are synthesized by ligand-free palladium nanoparticles catalyzed copper-free and amine-free Sonogashira cross-coupling reactions between aryl iodides and trimethylsilylacetylene (TMSA) under mild reaction conditions.
- Mandali, Pavan Kumar,Chand, Dillip Kumar
-
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- The copper-free Sonogashira cross-coupling reaction promoted by palladium complexes of nitrogen-containing chelating ligands in neat water at room temperature
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The commercially available 2,2′-dipyridylamine was used as a supporting ligand in the palladium-catalyzed Sonogashira cross-coupling reaction. The reactions between aryl iodides and terminal alkynes with different steric hindrance can be efficiently performed in the absence of copper in neat water at room temperature. The superior catalytic performance of the catalytic system was attributed to water solubility of the palladium 2,2′- dipyridylamine complex. Palladium nanoparticles with small size and narrow size distribution were formed after the cross-coupling reaction.
- Zhong, Hong,Wang, Jinyun,Li, Liuyi,Wang, Ruihu
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p. 2098 - 2103
(2014/01/17)
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- A convenient regioselective synthesis of cyclopentadienones via palladium-catalyzed [2+2+1] cyclocarbonylation of alkynes
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A simple and efficient synthesis of cyclopentadienones via palladium-catalyzed cyclocarbonylation of alkynes under atmospheric pressure of carbon monoxide has been developed. The transformation was carried out under mild and ligand-free conditions, a wide range of substrates and exceptional functional group tolerance.
- Xu, Yanli,Zhao, Jinwu,Chen, Huoji,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 2488 - 2490
(2014/03/21)
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- Palladium-ADC complexes as efficient catalysts in copper-free and room temperature Sonogashira coupling
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The metal-mediated coupling between cis-[PdCl2(CNR 1)2] [R1 = cyclohexyl (Cy) 1, t-Bu 2, 2,6-Me2C6H3 (Xyl) 3, 2-Cl-6-MeC 6H3 4] and hydrazones H2
- Valishina, Elena A.,Silva, M.Fátima C. Guedes Da,Kinzhalov, Mikhail A.,Timofeeva, Svetlana A.,Buslaeva, Tatyana M.,Haukka, Matti,Pombeiro, Armando J.L.,Boyarskiy, Vadim P.,Kukushkin, Vadim Yu.,Luzyanin, Konstantin V.
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p. 162 - 171
(2014/11/07)
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- Re/Mg bimetallic tandem catalysis for [4+2] annulation of benzamides and alkynes via C-H/N-H functionalization
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A rhenium-magnesium cocatalyzed [4+2] annulation of benzamides and alkynes via C-H/N-H functionalization is described. The reaction features a divergent and high level of diastereoselectivities, which are readily switchable by subtle tuning of reaction conditions. Thus, a wide range of both cis- and trans-3,4-dihydroisoquinolinones is expediently synthesized in a highly atom-economical manner. Moreover, mechanistic studies unraveled a tandem mode of action between rhenium and magnesium in the catalytic cycles.
- Tang, Qiuzheng,Xia, Dexin,Jin, Xiqing,Zhang, Qing,Sun, Xiao-Qiang,Wang, Congyang
-
supporting information
p. 4628 - 4631
(2013/05/21)
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- Microwave-promoted copper-free Sonogashira-Hagihara couplings of aryl imidazolylsulfonates in water
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Aryl imidazol-1-ylsulfonates have been efficiently cross-coupled with aryl-, alkyl-, and silylacetylenes in neat water under copper-free conditions at 110 °C assisted by microwave irradiation. Using 0.5mol% of an oxime palladacycle as precatalyst, 2-dicyclohexylphosphino-2′,6′- dimethoxybiphenyl (SPhos, 2mol%) as ligand, hexadecyltrimethylammonium bromide (CTAB) as additive, and triethylamine (TEA) as base, a wide array of disubstituted alkynes has been prepared in good to high yields in only 30min. Copyright
- Civicos, Jose F.,Alonso, Diego A.,Najera, Carmen
-
supporting information
p. 203 - 208
(2013/03/14)
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- Palladium-catalyzed oxidative annulation via C-H/N-H functionalization: Access to substituted pyrroles
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Pyrroles, ubiquitous bioactive heterocycles in nature, are readily prepared via a palladium-catalyzed oxidative annulation of cyclic trans-enamines to various internal alkynes in the absence of a directing group. Copyright
- Peng, Shiyong,Wang, Lei,Huang, Jiayao,Sun, Shaofa,Guo, Haibing,Wang, Jian
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supporting information
p. 2550 - 2557
(2013/10/21)
-
- Coupling reactions of aromatic halides with palladium catalyst immobilized on poly(vinyl alcohol) nanofiber mats
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Nanoporous poly(vinyl alcohol) (PVA) nanofiber mats prepared by means of electrospinning have been used for the immobilization of palladium catalyst. Thermal treatment of the palladium-loaded PVA nanofiber mats results in the cross-linking of the matrix PVA molecules as well as the reduction of the divalent palladium (Pd2+) into zerovalent palladium (Pd0) species. The palladium oxidation states were examined by X-ray photoelectron spectroscopic (XPS) analysis. The PVA nanofiber morphology was characterized by scanning electron microscopy (SEM). The catalytic activity and recyclability of the prepared heterogeneous palladium catalysts have been evaluated for the Ullmann, Heck-Mizoroki and Sonogashira coupling reactions of aromatic halides. The large structure of the Pd/PVA nanofiber mats can greatly facilitate its separation and recycling, and the high catalytic activity and stability of the prepared Pd/PVA nanofiber mats have been attributed to the chelation of palladium species with the abundant hydroxyl functional groups on the PVA matrix surface area.
- Shao, Linjun,Ji, Weixin,Dong, Pengdu,Zeng, Minfeng,Qi, Chenze,Zhang, Xian-Man
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experimental part
p. 267 - 272
(2012/03/26)
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- Mild Pd/Cu-catalyzed sila-sonogashira coupling of (hetero)aryl bromides with (hetero)arylethynylsilanes under PTC conditions
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The palladium/copper cocatalyzed sila-Sonogashira reaction of (hetero)arylethynysilanes with (hetero)aryl bromides in toluene and water at 40 C under PTC conditions gave the required di(hetero)arylethynes in moderate to high yields. Activated, deactivated and ortho-substituted (hetero)aryl bromides are well tolerated. This protocol also allowed the preparation of symmetrical diarylethynes by double arylation of 1,2-bis(trimethylsilyl)ethyne. Georg Thieme Verlag Stuttgart · New York.
- Bellina, Fabio,Lessi, Marco
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experimental part
p. 773 - 777
(2012/07/01)
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- Base-mediated selective synthesis of diversely substituted N-heterocyclic enamines and enaminones by the hydroamination of alkynes
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Regio- and stereoselective alkynylation of various N-heterocycles 1a-l using potassium and cesium salts in DMSO is described. Terminal alkynes 2a-k and internal alkynes 4a-f provided the kinetically stable Z-enamines 3a-l and 5a-i in good to excellent yields using KOH at 120 °C. Addition of heterocyclic amines to 1,3- and 1,4-diethynylbenzene 6a-b provided the mixture of E/Z isomers with KOH; however, with Cs2CO3 selectively Z-isomers 7ab-db were obtained by the hydroamination at one triple bond. This developed methodology also provides an easy and novel access for the synthesis of enaminones 10a-c. The detailed work also supports the formation of cis-isomer by preferential addition of o-haloarylalkynes followed by intramolecular C2 arylation in the copper-catalyzed tandem synthesis of indolo and pyrrolo[2,1-a]isoquinolines.
- Joshi, Megha,Patel, Monika,Tiwari, Rakesh,Verma, Akhilesh K.
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experimental part
p. 5633 - 5645
(2012/08/07)
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- A conjunctive carboiodination: Indenes by a double carbopalladation- reductive elimination domino process
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Something gained, nothing lost: A Pd0-catalyzed domino intermolecular/intramolecular process terminated by carbohalogenation is reported. In this reaction, two new C-C bonds, one new C-I bond and one five-membered ring are formed in a single step, and all of the atoms in the starting materials are incorporated into the product (see scheme). Copyright
- Jia, Xiaodong,Petrone, David A.,Lautens, Mark
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supporting information
p. 9870 - 9872
(2012/10/30)
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- Calcium carbide as a cost-effective starting material for symmetrical diarylethynes via Pd-catalyzed coupling reaction
-
A convenient and cost-effective synthetic method for symmetrical diarylethynes from inexpensive calcium carbide and aryl iodide has been developed. The reaction not only proceeds with high yield and selectivity but also tolerates a wide range of functional groups. Application of this reaction has enabled the synthesis of highly functionalized oligo (phenyleneethynylenes) to be accomplished.
- Chuentragool, Padon,Vongnam, Kunnigar,Rashatasakhon, Paitoon,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
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experimental part
p. 8177 - 8182
(2011/10/31)
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- Highly active palladium catalyst for the sonogashira coupling reaction of unreactive aryl chlorides
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This communication reports on the β-diketiminatophosphane palladium-catalyzed copper-free Sonogashira coupling of aryl chlorides with alkynes. A catalyst loading of 0.5 mol% is sufficient to achieve high performance under relatively mild reaction conditio
- Lee, Dong-Hwan,Kwon, Young-Jun,Jin, Myung-Jong
-
supporting information; experimental part
p. 3090 - 3094
(2012/01/03)
-
- Utility of dysprosium as a reductant in coupling reactions of acyl chlorides: The synthesis of amides and diaryl-substituted acetylenes
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Reduction of acyl chlorides with dysprosium metal has been studied. The reducing ability of dysprosium metal is solvent-dependent. Dysprosium metal, which requires neither any additive nor pretreatment, can promote the cross-coupling of acyl chlorides in DMF or DEF to give amides in good yields. When the reaction was performed in N,N-dimethylacetamide, the reductive self-coupling reaction of aroyl chloride took place smoothly and afforded the diaryl-substituted acetylenes in moderate to good yield.
- Chen, Weifeng,Li, Kebin,Hu, Ziqiang,Wang, Liliang,Lai, Guoqiao,Li, Zhifang
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experimental part
p. 2026 - 2030
(2011/06/18)
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- One-pot synthesis of 1,4-diarylsubstituted 1,3-diynes from the sequential coupling reactions of aryl iodides and propiolic acid
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1,4-Disubstituted 1,3-dialkynes were obtained from the one-pot palladium/copper-catalyzed coupling reactions of aryl iodide and propiolic acid. The optimized catalytic system consisted of 5.0 mol % Pd(PPh3) 2Cl2, 10 mol % dppb, 10 mol % CuI, 2.4 equiv of DBU, and 1.2 equiv of K2CO3. The coupling reaction was carried out at 30 °C for 6 h and subsequently at 80 °C for 3 h.
- Kim, Yong,Park, Ahbyeol,Park, Kyungho,Lee, Sunwoo
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experimental part
p. 1766 - 1769
(2011/05/05)
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- Synthesis of symmetrical diarylalkyne from palladium-catalyzed decarboxylative couplings of propiolic acid and aryl bromides under water
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Symmetric diarylalkynes were obtained from the decarboxylative coupling reactions of aryl bromides and propiolic acid in water solvent condition. In the presence of phase transfer surfactant C18H37N(CH 3)3Cl, the catalytic system of both Pd(PPh 3)2Cl2/dppb and Pd(TPPMS)2Cl 2/TPPMS afforded the desired coupled products in good yields.
- Park, Kyungho,Bae, Goun,Park, Ahbyeol,Kim, Yong,Choe, Jaehoon,Song, Kwang Ho,Lee, Sunwoo
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experimental part
p. 576 - 580
(2011/03/18)
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- Photochemical behavior of (diphosphine)(η2-tolane)Pt 0 complexes. Part A: Experimental considerations in solution and in the solid state
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A series of various (diphosphine)(η2-tolane)Pt0 complexes exhibiting manifold substitution pattern of the tolane ligand (5a-g) and different rigid diphosphines defining various bite angles at the Pt center (9a-b) have been synthesized. All compounds were isolated and characterized by means of spectroscopic methods and additionally by X-ray structure determination (5a-e, 9a-b). In view of potential Caryl-Cethynyl bond activation, we investigated their photochemical behavior in the solid state as well as in solution by irradiating with sunlight. The reactivity towards C aryl-Cethynyl bond activation in the crystalline state and in solution is discussed in relation to substituents attached to the tolane ligand and on the extent of the torsion of its phenyl rings. Complexes 5a-c and 9a either bearing electron withdrawing bromides or possessing a large dihedral angle of the phenyl rings, showed selective oxidative addition of the C aryl-Cethynyl bond to the Pt center in the solid state, yielding complexes 6a-c and 10a, respectively. In contrast, 5d-f and 9b proved to be unreactive under similar conditions because of their electron donating methoxy groups as well as the reduced twisting of their phenyl or pyridyl moieties of the tolane ligands. Irradiation of complexes 5a and 5b with sunlight in solution revealed the formation of the appropriate C-Br activated compounds 7a and 7b along with 6a and 6b in a 1:1 mixture. The observed photochemical Caryl-Cethynyl bond activation is reversible under thermal conditions, regaining the appropriate Pt0 complexes by reductive elimination.
- Weisheit, Thomas,Escudero, Danie,Petzold, Holm,Goerls, Helmar,Gonzalez, Leticia,Weigand, Wolfgang
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p. 9493 - 9504
(2011/01/11)
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- Synthesis of symmetrical and unsymmetrical diarylalkynes from propiolic acid using palladium-catalyzed decarboxylative coupling
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Figure presented. Symmetrical diarylalkynes were obtained from propiolic acid (or 2-butynedioic acid) and aryl halides in good yields. The optimized reaction conditions were 2.0 equiv of aryl halide, 1.0 equiv of propiolic acid, 5.0 mol % Pd(PPh3/su
- Park, Kyungho,Bae, Goun,Moon, Jeongju,Choe, Jaehoon,Song, Kwang Ho,Lee, Sunwoo
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experimental part
p. 6244 - 6251
(2010/12/20)
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- Ambient temperature hydrophosphination of internal, unactivated alkynes and allenyl phosphineoxides with phosphine borane complexes
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[Chemical Equation Presented] Phosphine boranes have been found to hydrophosphinate Internal, unactivated alkynes at room temperature under basic conditions without the need for catalysts or radical initiators. The use of air-sensitive secondary phosphine
- Busacca, Carl A.,Farber, Elisa,Deyoung, Jay,Campbell, Scot,Gonnella, Nina C.,Grinberg, Nelu,Haddad, Nizar,Lee, Heewon,Ma, Shengli,Reeves, Diana,Shen, Sherry,Senanayake, Chris H.
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supporting information; experimental part
p. 5594 - 5597
(2010/03/05)
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- Catalyst for alkyne metathesis
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The invention provides catalytically active compounds for alkyne metathesis comprising a ligand, on his part containing a guanidinate core which is forming a complex with a transition metal atom. Formally, the guanidinate core is a mononegative ligand that binds with the metal atom. One or both of the nitrogen atoms of the guanidiate core, which are not participating in the metal complexing bond, can be substituted with substituents being selected from hydrogen, alkyl, alkenyl, aromatic residues, optionally including hetero atoms, e.g. halogen atoms, preferably fluorine.
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Page/Page column 8
(2009/01/24)
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- Efficient room-temperature alkyne metathesis with well-defined imidazolin-2-iminato tungsten alkylidyne complexes
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(Chemical Equation Presented) It's a game of give and take: Following the successful design strategy for high-oxidation-state alkene metathesis catalysts of the Schrock type, one of the most active homogeneous catalyst systems for alkyne metathesis has been developed. The activity of the tungsten alkylidyne complex (see picture) stems from the use of a strong electron-donating imidazolin-2-iminato ligand together with electron-withdrawing fluorinated alkoxides.
- Beer, Stephan,Hrib, Cristian G.,Jones, Peter G.,Brandhorst, Kai,Grunenberg, Joerg,Tamm, Matthias
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p. 8890 - 8894
(2008/09/20)
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- Coupling reactions of ortho-substituted halobenzenes with alkynes. The synthesis of phenylacetylenes and symmetrical or unsymmetrical 1,2-diphenylacetylenes
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The Pd- or Pd/Cu-catalyzed coupling reactions of halobenzenes bearing the methyl, hydroxymethyl, acetoxymethyl, methoxycarbonyl, or both methoxy and 4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl groups in the ortho-position with gaseous or metallated acetylene, (trialkylsilyl)acetylenes, and arylacetylenes have been systematically studied. Various functionalized aryl- or diarylacetylenes have been synthesized in good to excellent yields. Whereas additional fluoro, nitro, or methoxy group attached to the benzene ring does not interfere in the coupling reactions, the presence of a methoxycarbonyl requires a careful optimization of reaction conditions to achieve moderate yields.
- Stara, Irena G.,Stary, Ivo,Kollarovic, Adrian,Teply, Filip,Saman, David,Fiedler, Pavel
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p. 649 - 672
(2007/10/03)
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- Alkyne metathesis with simple catalyst systems: High yield dimerization of propynylated aromatics; scope and limitations
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High yield dimerization of propynylated benzenes and propynylnaphthalene by a mixture of Mo(CO)6 and 4-chlorophenol at 140 °C in 1,2-dichlorobenzene is reported to give the corresponding disubstituted alkynes. The scope and limitation of the reaction and the influence of substitution pattern and substitution type are discussed. Oxygen or nitrogen carrying substrates metathesize in moderate to good yields and ortho-alkyl substituted examples form the respective tolanes very efficiently.
- Pschirer, Neil Gregory,Bunz, Uwe H. F.
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p. 2481 - 2484
(2007/10/03)
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- A facile and high yielding synthesis of symmetrical and unsymmetrical diarylalkynes using diethyl dichloromethylphosphonate as precursor
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The reaction, under internal quench conditions, of diethyl dichloromethylphosphonate and symmetrical or unsymmetrical diaryl ketones in the presence of n-BuLi, leads to the corresponding symmetrical or unsymmetrical diarylalkynes via a Fritsch-Buttenherg-Wiechell rearrangement in a simple, high yielding, one-pot reaction.
- Mouriès, Virginie,Waschbüsch, Rachel,Carran, John,Savignac, Philippe
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p. 271 - 274
(2007/10/03)
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- Coupling reactions of ortho-substituted aryl halides with alkynes. The synthesis of functionalized 1-naphthyl-, 1-(1-naphthyl)-2-phenyl-, and 1,2- bis(1-naphthyl)acetylenes
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Coupling of 2-functionalized 1-naphthyl halides with gaseous acetylene, (trialkylsilyl)acetylenes, and aryl acetylenes under Pd(PPh3)4 or Pd(PPh3)4/CuI catalysis has been investigated to prepare 1-naphthyl-, 1-
- Stara, Irena G.,Stary, Ivo,Kollarovic, Adrian,Teply, Filip,Saman, David,Fiedler, Pavel
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p. 11209 - 11234
(2007/10/03)
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- Stereoselective addition of diphenylphosphine to substituted diphenylethynes: Synthetic, NMR and X-ray crystallographic studies
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The base-catalysed addition of diphenylphosphine to the substituted diphenylethynes RC≡CR′ (R = Ph, R′ = Ph, o-tolyl, m-tolyl or 2-biphenyl; R = m-tolyl, R′ = o-tolyl or m-tolyl) yielded Ph2PC(R)=CHR′ and/or Ph2PCH(R)CH(R′)PPh2. Proton, 13C, 13P and two-dimensional rotating frame Overhauser enhancement 1H NMR spectra have been used to determine the stereochemical pathways of the reactions and the stereochemistry of the products. In general the more hindered alkynes undergo monoaddition ultimately to yield phosphinoalkenes with the Ph2P attached to the carbon bearing the least bulky substituent and cis to the olefinic proton, while for the less hindered alkynes the trans isomer is formed initially and this then reacts further to give mesolerythro-diphosphinoalkanes. Bis(o-tolyl)ethyne does not react with Ph2PH under the same conditions. Crystal structures were determined for E- and Z-Ph2P(Ph)C=CHPh and show distortions of interbond angles consistent with the pattern of strain implied by the foregoing reactions. The sulfides of the phosphinoalkenes and the Mo(CO)4 complexes of the diphosphinoalkanes were also prepared and their 1H, 13C and 31P NMR spectra recorded. In several cases the pattern of 13CO NMR signals for the complexes was used unambiguously to determine the stereochemistry of the parent diphosphines.
- Bookham, Jonathan L.,Smithies, Darren M.,Wright, Anna,Thornton-Pett, Mark,McFarlane, William
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p. 811 - 818
(2007/10/03)
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- Naturally occurring 5-[2-thienyl)ethynyl]thiophene-2-carbaldehyde through a short synthesis of diarylacetylenes
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Title compound and related diarylacetylenes were synthesized via a one-pot procedure starting from aryliodide and trimethylsilylacetylene.
- D'Auria
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p. 2393 - 2399
(2007/10/02)
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- REDUCTIVE COUPLING OF BENZOIC ACID HALIDES AND ESTERS USING LOW-VALENT TITANIUM
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The reductive coupling of (substituted) benzoic acid chlorides and esters is achieved using low-valent titanium, generated from TiCl3 and LiAlH4.Both acid chlorides and esters seem to follow the same two reaction pathways: one path via tolanes to stilbenes, the other via benzils to complex mixtures of products arising from reduction and further coupling reactions.Although the exact product balance depends upon the reaction conditions the major product is (substituted) cis-stilbene.
- Dang, Y.,Geise, H. J.
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p. 375 - 380
(2007/10/02)
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