- Tosyloxybenziodoxolone: A Platform for Performing the Umpolung of Alkynes in One-Pot Transformations
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Ethynylbenziodoxolones (EBXs) are commonly encountered reagents for the electrophilic alkynylation of nucleophiles. Herein, we report a one-pot, two-step process for EBX generation and their direct application in substrate functionalization. Our approach enables us to bypass the originally mandatory isolation and purification of the reagents, resulting in a more efficient synthesis. We could apply this process to seven different transformations involving both two- and one-electron nucleophiles to obtain a large variety of alkynylated products.
- Borrel, Julien,Waser, Jerome
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p. 142 - 146
(2021/12/27)
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- Metal-Free Synthesis of Selenodihydronaphthalenes by Selenoxide-Mediated Electrophilic Cyclization of Alkynes
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A transition-metal-free, selenium mediated electrophilic cyclization reaction was realized through a one-pot procedure between simple alkynes and triflic anhydride-activated selenoxides to give selenium containing dihydronaphthalene products. This method gave good to very high yields for all products, including selenium-substituted phenanthrene, dihydroquinoline, 2H-chromene, and coumarin, which can be further transformed to other functionalized compounds.
- An, Shaoyu,Li, Pingfan,Zhang, Zhong
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p. 3059 - 3070
(2021/07/22)
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- Nickel-Catalyzed Sonogashira Coupling Reactions of Nonactivated Alkyl Chlorides under Mild Conditions
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The two nickel chlorides1and2with [P,S] and [P,Se] bidentate ligands, respectively, were synthesized and used as catalysts for Sonogashira coupling reaction. Both1and2are efficient catalysts for Sonogashira C(sp3)-C(sp) coupling reactions. Comp
- Fan, Qingqing,Sun, Hongjian,Xie, Shangqing,Dong, Yanhong,Li, Xiaoyan,Fuhr, Olaf,Fenske, Dieter
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p. 2240 - 2245
(2021/04/06)
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- Direct Photoexcitation of Ethynylbenziodoxolones: An Alternative to Photocatalysis for Alkynylation Reactions**
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Ethynylbenziodoxolones (EBXs) are commonly used as radical traps in photocatalytic alkynylations. Herein, we report that aryl-substituted EBX reagents can be directly activated by visible light irradiation. They act as both oxidants and radical traps, alleviating the need for a photocatalyst in several reported EBX-mediated processes, including decarboxylative and deboronative alkynylations, the oxyalkynylation of enamides and the C?H alkynylation of THF. Furthermore, the method could be applied to the synthesis of alkynylated quaternary centers from tertiary alcohols via stable oxalate salts and from tertiary amines via aryl imines. A photocatalytic process using 4CzIPN as an organic dye was also developed for the deoxyalkynylation of oxalates.
- Amos, Stephanie G. E.,Cavalli, Diana,Le Vaillant, Franck,Waser, Jerome
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supporting information
p. 23827 - 23834
(2021/09/25)
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- Cu-Photoredox-catalyzed C(sp)-C(sp3) coupling of redox-active esters with terminal alkynes
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Visible-light-induced C(sp)-C(sp3) coupling of redox-active esters with terminal alkynes has been developed. The activation of carboxylic acids as their redox-active ester derivatives was important for this decarboxylative alkynylation. The strategy established here facilitates the straightforward introduction of triple-bonded functional groups and avoids additional photocatalysts. A wide range of primary, secondary and tertiary acids can be converted into the target products; so this reaction exhibits a broad substrate scope and tolerance of functional groups. Mechanistic experiments suggested that this reaction may undergo a radical process. Under mild reaction conditions, a copper acetylide ligand as a photocatalyst delivered an electron to redox-active ester derivatives, and generated alkyl radicals. The radicals reacted with Cu(ii) to deliver a Cu(iii) complex, and then reductive elimination gave the products.
- Zhang, Dayong,Zhang, Yajing
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supporting information
p. 4479 - 4483
(2020/10/20)
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- Metal-Free Visible-Light-Mediated Aromatization of 1,2–Dihydronaphthalenes
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A series of polyaromatic naphthalenes have been synthesized through the dehydrogenation of the corresponding 1,2-dihydroarylnaphthalenes by using 9-mesityl-10-methylacridinium perchlorate as a photocatalyst and diphenyliodonium triflate as an external oxidant under visible light irradiation. The reaction proceeds smoothly under metal-free conditions and tolerates some functionalities. Interestingly, the reaction is also amenable to the aromatization of tetrahydronaphthalenes and fair conversions were obtained. Preliminary mechanistic investigations have been conducted and a reasonable mechanism is proposed.
- Rammal, Fatima,Gaumont, Annie-Claude,Lakhdar, Sami
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supporting information
p. 1482 - 1485
(2019/12/12)
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- Visible light-driven cross-coupling reactions of alkyl halides with phenylacetylene derivatives for C(sp3)-C(sp) bond formation catalyzed by a B12 complex
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Visible light-driven cross-coupling reactions of alkyl halides with phenylacetylene and its derivatives catalyzed by the cobalamin derivative (B12) with the [Ir(dtbbpy)(ppy)2]PF6 photocatalyst at room temperature are reported. The robust B12 catalyst and Ir photocatalyst provided high turnover numbers of over 33?000 for the reactions.
- Chen, Li,Kametani, Yohei,Imamura, Kenji,Abe, Tsukasa,Shiota, Yoshihito,Yoshizawa, Kazunari,Hisaeda, Yoshio,Shimakoshi, Hisashi
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supporting information
p. 13070 - 13073
(2019/11/11)
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- Balancing Bulkiness in Gold(I) Phosphino-triazole Catalysis
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The syntheses of a series of 1-phenyl-5-phosphino 1,2,3-triazoles are disclosed, within which, the phosphorus atom (at the 5-position of a triazole) is appended by one, two or three triazole motifs, and the valency of the phosphorus(III) atom is completed by two, one or zero ancillary (phenyl or cyclohexyl) groups respectively. This series of phosphines was compared with tricyclohexylphosphine and triphenylphosphine to study the effect of increasing the number of triazoles appended to the central phosphorus atom from zero to three triazoles. Gold(I) chloride complexes of the synthesised ligands were prepared and analysed by techniques including single-crystal X-ray diffraction structure determination. Gold(I) complexes were also prepared from 1-(2,6-dimethoxy)-phenyl-5-dicyclohexyl-phosphino 1,2,3-triazole and 1-(2,6-dimethoxy)-phenyl-5-diphenyl-phosphino 1,2,3-triazole ligands. The crystal structures thus obtained were examined using the SambVca (2.0) web tool and percentage buried volumes determined. The effectiveness of these gold(I) chloride complexes to serve as precatalysts for alkyne hydration were assessed. Furthermore, the regioselectivity of hydration of but-1-yne-1,4-diyldibenzene was probed.
- Zhao, Yiming,Wakeling, Matthew G.,Meloni, Fernanda,Sum, Tze Jing,van Nguyen, Huy,Buckley, Benjamin R.,Davies, Paul W.,Fossey, John S.
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supporting information
p. 5540 - 5548
(2019/08/07)
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- Conjugated mesoporous polyazobenzene–Pd(II) composite: A potential catalyst for visible-light-induced Sonogashira coupling
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We herein report the direct harnessing of visible light energy by a novel semiconducting azobenzene-based colloidal porous organic polymer, B3-Azo4 amenable to post-synthetic Pd(II)-complexation for photo-induced Sonogashira coupling using polymer → metal energy transfer process. Completely mesoporous nano-sized particles of the obtained organic network manifested excellent Pd(II) coordinating ability and afforded desired catalytic products at room temperature under aerobic condition in aqueous medium. The protocol remained valid for different aromatic and aliphatic substrates as well. A possible reaction mechanism for photo-mediated Sonogashira coupling catalyzed by Pd-B3-Azo4 is also proposed.
- Nath, Ipsita,Chakraborty, Jeet,Khan, Anish,Arshad, Muhammad N.,Azum, Naved,Rab, Malik A.,Asiri, Abdullah M.,Alamry, Khalid A.,Verpoort, Francis
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p. 183 - 189
(2019/08/07)
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- Synthesis of Internal Alkynes through an Effective Tandem Elimination-Hydrodebromination-Cross-Coupling of gem-Dibromoalkenes with Halobenzenes
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Carbon-carbon couplings are among the most important strategies for constructing functional molecules in organic synthetic chemistry, and cheap, diverse, and readily available coupling partners are crucial to these diverse reactions. In this contribution, we report the first palladium-catalyzed C-C cross-coupling reaction of two kinds of organic halide, a gem -dibromoalkene and a halobenzene, as the starting materials. Terminal alkynes were generated in situ through a tandem elimination-hydrodebromination process, and the internal alkyne final products were synthesized in one pot. The reaction proceeded under simple, facile, and classic copper-free Sonogashira coupling reaction conditions in good to excellent yields.
- Ji, Yuan,Zhong, Ning,Kang, Zinan,Yan, Guobing,Zhao, Ming
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supporting information
p. 209 - 214
(2018/03/26)
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- Redox-Activated Amines in C(sp3)-C(sp) and C(sp3)-C(sp2) Bond Formation Enabled by Metal-Free Photoredox Catalysis
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The amino group represents one of the most prevalent structural motifs in organic chemistry. Therefore, application of amines as alkylating agents in synthesis is highly compelling. Herein, we present a metal-free photoredox strategy for the formation of C(sp3)-C(sp) and C(sp3)-C(sp2) bonds from redox-activated primary amine derivatives. The developed reaction of 2,4,6-triphenylpyridinium salts with alkynyl p-tolylsulfones, leading to functionalized alkynes, is easily scalable and offers broad substrate scope, high chemoselectivity, and mild conditions. Its potential is also highlighted by diversification of complex molecular scaffolds. Additionally, the approach is also suitable for synthesis of (E)-alkenes from vinyl phenyl sulfones. Mechanistic studies contribute to the elucidation of unexpected differences in reactivity of primary and secondary alkyl substituted pyridinium salts.
- Ociepa, Micha,Turkowska, Joanna,Gryko, Dorota
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p. 11362 - 11367
(2018/11/23)
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- Sonogashira reactions of alkyl halides catalyzed by NHC [CNN] pincer nickel(II) complexes
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C(carbene)N(amido)N(amine)-pincer nickel(ii) complexes [iPrCNN-Ni-Br] (6), [nBuCNN-Ni-Br] (7) and [BnCNN-Ni-Cl] (8) were synthesized. The catalytic performance of complexes 6-8 for Sonogashira cross-coupling reactions was
- Wang, Zijing,Zheng, Tingting,Sun, Hongjian,Li, Xiaoyan,Fuhr, Olaf,Fenske, Dieter
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p. 11465 - 11470
(2018/07/24)
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- An Interrupted Pummerer/Nickel-Catalysed Cross-Coupling Sequence
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An interrupted Pummerer/nickel-catalysed cross-coupling strategy has been developed and used in the elaboration of styrenes. The operationally simple method can be carried out as a one-pot process, involves the direct formation of stable alkenyl sulfonium salt intermediates, utilises a commercially available sulfoxide, catalyst, and ligand, operates at ambient temperature, accommodates sp-, sp2-, and sp3-hybridised organozinc coupling partners, and delivers functionalised styrene products in high yields over two steps. An interrupted Pummerer/cyclisation approach has also been used to access carbo- and heterocyclic alkenyl sulfonium salts for cross-coupling.
- Aukland, Miles H.,Talbot, Fabien J. T.,Fernández-Salas, José A.,Ball, Matthew,Pulis, Alexander P.,Procter, David J.
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supporting information
p. 9785 - 9789
(2018/07/31)
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- Recyclable heterogeneous metal foil-catalyzed cyclopropenation of alkynes and diazoacetates under solvent-free mechanochemical reaction conditions
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Silver and copper foil were found to be effective, versatile and selective heterogeneous catalysts for the cyclopropenation of terminal and internal alkynes under mechanochemical reaction conditions. This methodology enables the functionalization of a wide range of terminal or internal alkynes under ambient, aerobic, and solvent-free conditions. Finally, we have demonstrated a unique and versatile one-pot domino Sonogashira-cyclopropenation mechanochemical reaction for the formation of complex cyclopropenes.
- Chen, Longrui,Leslie, Devonna,Coleman, Michael G.,Mack, James
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p. 4650 - 4661
(2018/05/30)
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- Sonogashira reaction using arylsulfonium salts as cross-coupling partners
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Triarylsulfonium, alkyl- and fluoroalkyl(diaryl)-sulfonium, and aryl(dialkyl)sulfonium triflates are successfully used as a new family of cross-coupling participants in the Sonogashira reaction as aryldiazonium, diaryliodonium, and tetraphenylphosphonium salts. It was found that terminal alkynes reacted mildly with triarylsulfonium or (2,2,2-trifluoroethyl)diphenylsulfonium triflate at room temperature under Pdand Cu-cocatalysis to give the corresponding arylalkynes in up to >99% yield. This protocol represents the first use of arylsulfonium salts as cross-coupling partners in the Pd/Cu-catalyzed Sonogashira reaction.
- Tian, Ze-Yu,Wang, Shi-Meng,Jia, Su-Jiao,Song, Hai-Xia,Zhang, Cheng-Pan
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p. 5454 - 5457
(2017/11/06)
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- Transmetalation of Alkylzirconocenes in Copper-Catalyzed Alkyl–Alkynyl Cross-Coupling Reactions
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A simple copper-catalyzed alkyl–alkynyl cross-coupling strategy has been developed using the reaction between alkynyl bromides and alkylzirconocenes. The alkylzirconocenes were generated in situ via regioselective addition of Schwartz's reagent (ZrCp2HCl) on to alkenes. The reaction has a broad scope, a range of functionalized bromoalkynes and alkylzirconium reagents were successfully coupled, resulting in moderate to good yields of the desired internal alkynes. (Figure presented.).
- Indukuri, Kiran,Riant, Olivier
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p. 2425 - 2433
(2017/07/22)
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- N-Heterocyclic carbene copper-catalyzed direct alkylation of terminal alkynes with non-activated alkyl triflates
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(NHC)-Cu-catalyzed C(sp)-C(sp3) bond formation has been successfully achieved under mild conditions. Nonactivated alkyl triflates, which could be easily derived from alcohols, were utilized as C-O electrophiles. Mechanistic studies suggested th
- Jin, Liqun,Hao, Wangfang,Xu, Jianeng,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Mo, Weimin,Hu, Xinquan
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supporting information
p. 4124 - 4127
(2017/04/13)
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- A metal-free transformation of alkynes to carbonyls directed by remote OH group
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A remote OH group-directed metal-free transformation of alkynes to carbonyl compounds has been developed. Using only HOAc and EtOH solvent, this reaction elegantly converts alkynes into valuable ketones by remote hydroxyl group activation. Through comparison and isotope labeling experiments, it was confirmed that the process operates via a hydration reaction involving an acetic acid molecule, instead of a water molecule.
- Chen, Dao-Qian,Guo, Chun-Huan,Zhang, Heng-Rui,Jin, Dong-Po,Li, Xue-Song,Gao, Pin,Wu, Xin-Xing,Liu, Xue-Yuan,Liang, Yong-Min
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supporting information
p. 4176 - 4180
(2016/08/02)
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- Photosensitizer-Free Visible-Light-Mediated Gold-Catalyzed 1,2-Difunctionalization of Alkynes
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Under visible-light irradiation, the gold-catalyzed intermolecular difunctionalization of alkynes with aryl diazonium salts in methanol affords a variety of α-aryl ketones in moderate to good yields. In contrast to previous reports on gold-catalyzed reactions that involve redox cycles, no external oxidants or photosensitizers are required. The reaction proceeds smoothly under mild reaction conditions and shows broad functional-group tolerance. Further applications of this method demonstrate the general applicability of the arylation of a vinyl gold intermediate instead of the commonly used protodemetalation step. This step provides facile access to functionalized products in one-pot processes. With a P,N-bidentate ligand, a stable aryl gold(III) species was obtained, which constitutes the first direct experimental evidence for the commonly postulated direct oxidative addition of an aryl diazonium salt to a pyridine phosphine gold(I) complex.
- Huang, Long,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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supporting information
p. 4808 - 4813
(2016/04/19)
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- Formation of C(sp2) Boronate Esters by Borylative Cyclization of Alkynes Using BCl3
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BCl3is an inexpensive electrophile which induces the borylative cyclization of a wide range of substituted alkynes to regioselectively form polycycles containing synthetically versatile C(sp2) boronate esters. It proceeds rapidly, with good yields and is compatible with a range of functional groups and substitution patterns. Intermolecular 1,2-carboboration of alkynes is also achieved using BCl3to generate trisubstituted vinyl boronate esters.
- Warner, Andrew J.,Lawson, James R.,Fasano, Valerio,Ingleson, Michael J.
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supporting information
p. 11245 - 11249
(2016/07/06)
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- Decarboxylative Alkynylation and Carbonylative Alkynylation of Carboxylic Acids Enabled by Visible-Light Photoredox Catalysis
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Visible-light-induced photocatalytic decarboxylative alkynylations of carboxylic acids have been developed for the first time. The reaction features extremely mild conditions, broad substrate scope, and avoids additional oxidants. Importantly, a decarboxy
- Zhou, Quan-Quan,Guo, Wei,Ding, Wei,Wu, Xiong,Chen, Xi,Lu, Liang-Qiu,Xiao, Wen-Jing
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supporting information
p. 11196 - 11199
(2016/07/06)
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- Calcium-catalyzed carboarylation of alkynes
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The first transition-metal-free carboarylation of alkynes with commercial and readily available alcohols as alkylating agents was realized in the presence of an environmentally benign calcium catalyst. Thereby, a novel protocol for the one-step synthesis of highly congested, all-carbon tetrasubstituted alkenes, as incorporated in potentially bioactive, complex dihydronaphthalene, chromene and dihydroquinoline structures, is provided. The reaction features an unprecedented, particularly wide substrate scope, good functional-group tolerance and simple experimental operation under mild reaction conditions. Finally free: The first transition-metal-free one-step synthesis of highly congested, all-carbon tetrasubstituted olefins has been realized by a calcium-catalyzed carboarylation reaction. Internal alkynes react with alcohols as alkylating reagent under mild reaction conditions, which provides access to a variety of useful structural scaffolds via highly reactive trisubstituted vinyl cations.
- Fu, Liang,Niggemann, Meike
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supporting information
p. 6367 - 6370
(2015/04/22)
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- Visible-light-induced chemoselective deboronative alkynylation under biomolecule-compatible conditions
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Here, we report a visible-light-induced deboronative alkynylation reaction, which is redox-neutral and works with primary, secondary and tertiary alkyl trifluoroborates or boronic acids to generate aryl, alkyl and silyl substituted alkynes. This reaction is highly chemoselective and performs well on substrates containing alkenes, alkynes, aldehydes, ketones, esters, nitriles, azides, aryl halides, alkyl halides, alcohols, and indoles, with no detectable occurrence of side reactions. The mechanism of this novel C(sp3)-C(sp) bond coupling reaction was investigated by luminescence quenching, radical trapping, on-off light, and 13C-isotopic-labeling experiments. This reaction can be performed in neutral aqueous conditions, and it is compatible with amino acids, nucleosides, oligosaccharides, nucleic acids, proteins, and cell lysates.
- Huang, Hanchu,Zhang, Guojin,Gong, Li,Zhang, Shuaiyan,Chen, Yiyun
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p. 2280 - 2283
(2014/03/21)
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- Manganese(III)-mediated selective diphenylphosphinoyl radical reaction of 1,4-diaryl-1-butynes for the synthesis of 2-phosphinoylated 3,4- dihydronaphathalenes
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A diphenylphosphinoyl radical-initiated sequential reaction of 1,4-diaryl-1-butynes and analogues is developed for the synthesis of 2-phosphinoylated 3,4-dihydronaphathalenes and related compounds.
- Li, Da-Peng,Pan, Xiang-Qiang,An, Li-Tao,Zou, Jian-Ping,Zhang, Wei
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p. 1850 - 1855
(2014/03/21)
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- Copper-catalyzed carboarylation of alkynes via vinyl cations
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Copper-catalyzed arylation of electron rich alkynes reveals stabilized trisubstituted vinyl cation equivalents that react with pendant arene nucleophiles to form all carbon tetrasubstituted alkenes. The new process streamlines the synthesis of important medicinally relevant molecules.
- Walkinshaw, Andrew J.,Xu, Wenshu,Suero, Marcos G.,Gaunt, Matthew J.
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supporting information
p. 12532 - 12535
(2013/09/23)
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- Copper-catalyzed decarboxylative coupling of aryl halides with alkynyl carboxylic acids performed in water
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Most alkynes are volatile liquids, which are relatively difficult to use and to transport. In contrast, alkynyl carboxylic acids offer a stable and attractive alternative for the alkynylation reactions. Here, we employed alkynyl carboxylic acids as reaction partners for the alkynylation of aryl halides. Copper-catalyzed decarboxylative coupling, including various challenging aryl bromides with phenylpropiolic acid, was performed in water without using co-solvents with good yields. Our approach provides a low-loading, low-cost, stable and environmentally friendly copper catalyst system for decarboxylative coupling.
- Li, Tingyi,Sun, Peng,Yang, Hailong,Zhu, Yan,Yan, Hong,Lu, Linhua,Mao, Jincheng
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supporting information; experimental part
p. 6413 - 6419
(2012/08/27)
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- Highly effective copper-catalyzed decarboxylative coupling of aryl halides with alkynyl carboxylic acids
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We have developed a highly effective copper-catalyzed decarboxylative coupling of alkynylcarboxylic acids with various aryl and alkyl halides at 2 mol% loading of copper. This method is simple, economical and practical for the synthesis of disubstituted alkyne compounds.
- Qu, Xiaoming,Li, Tingyi,Sun, Peng,Zhu, Yan,Yang, Hailong,Mao, Jincheng
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supporting information; experimental part
p. 6938 - 6942
(2011/10/31)
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- Palladium-catalyzed Sonogashira reactions of aryl amines with alkynes via in situ formation of arenediazonium salts
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A general and convenient palladium-catalyzed Sonogashira reaction of in situ generated arenediazonium salts has been developed and various internal arylalkynes are produced in good yields under mild conditions.
- Wu, Xiao-Feng,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 7959 - 7961
(2011/08/05)
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- Silver triflate-catalyzed cyclopropenation of internal alkynes with donor-/acceptor-substituted diazo compounds
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Silver triflate was found to be an efficient catalyst for the cyclopropenation of internal alkynes using donor-/acceptor-substituted diazo compounds as carbenoid precursors. Highly substituted cyclopropenes, which cannot be synthesized directly via rhodium(II)-catalyzed carbenoid chemistry, can now be readily accessed.
- Briones, John F.,Davies, Huw M. L.
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supporting information; experimental part
p. 3984 - 3987
(2011/09/16)
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- Iron-catalyzed cross-coupling between 1-bromoalkynes and grignard-derived organocuprate reagents
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An efficient iron-catalyzed cross-coupling reaction between alkynyl bromides and Grignard-derived organocuprates has been developed. A series of alkynylarenes were successfully synthesised by starting from different 1-bromoalkynes and Grignard reagents. The methodology was successfully used for the two-step stereoselective synthesis of combretastatins and represents a valid alternative to the classical syntheses of alkynylarenes.
- Castagnolo, Daniele,Botta, Maurizio
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supporting information; experimental part
p. 3224 - 3228
(2010/08/20)
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- Palladium-catalyzed aerobic oxidative cross-coupling reactions of terminal alkynes with alkylzinc reagents
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Chemical Equation Represented With air as the oxidant, terminal alkynes can be directly cross-coupled with alkylzinc reagents in the presence of a Pd catalyst at room temperature. CO was found to be critical in gaining high chemical yields and selectivities. A wide range of alkynes and alkylzinc reagents were tested, and good to excellent yields were obtained. Copyright
- Chen, Mao,Zheng, Xiaolong,Li, Wenqing,He, Jun,Lei, Aiwen
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supporting information; experimental part
p. 4101 - 4103
(2010/05/14)
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- Selective oxidative ligand coupling of organoborates bearing an alkynyl group
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Selective oxidative ligand coupling of alkynyl(triaryl)borates was achieved by treatment with ethoxyvanadyl dichloride [VO(OEt)Cl2] to form the sp-sp2 carbon-carbon bond. A one-pot procedure through the in situ preparation of the bor
- Amaya, Toru,Tsukamura, Yusuke,Hirao, Toshikazu
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experimental part
p. 1025 - 1028
(2009/12/07)
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- Palladium-catalyzed R(sp3)-Zn/R(sp)-SnBu3 oxidative cross-coupling
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A novel bond formation through oxidative cross-coupling with desyl chloride as the oxidant has been investigated. The coupling can be carried out under mild conditions. The Csp3-center carbon was involved even in the presence of a β-H, and up to 90% of the desired cross-coupling product was obtained with the secondary Csp3-center substrate. Georg Thieme Verlag Stuttgart.
- Jin, Liqun,Zhao, Yingsheng,Wang, Haibo,Lei, Aiwen
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p. 649 - 654
(2008/12/21)
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- Ligand-free iron/copper cocatalyzed alkynylation coupling reactions
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Ligand-free iron/copper cocatalyzed cross-coupling reactions of aryl halides with terminal alkynes were carried out to provide the corresponding coupling products in good yields (up to 99%). Noteworthy is that this low-cost, effective and environmentally friendly protocol was the first to be employed in alkynylation couplings.
- Mao, Jincheng,Xie, Guanlei,Wu, Minyan,Guo, Jun,Ji, Shunjun
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experimental part
p. 2477 - 2482
(2009/09/07)
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- Oxidative cross-coupling through double transmetallation: Surprisingly high selectivity for palladium-catalyzed cross-coupling of alkylzinc and alkynylstannanes
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Two different organometallic reagents now can cross-couple together with the oxidative cross-coupling strategy. Palladium catalyzed oxidative cross-couplings of alkylzinc and alkynylstannane reagents using desyl chloride as the oxidant have been explored, which produce the desired Csp-Csp3 cross-coupling product in surprisingly high selectivity and yields. The current catalytic system tolerates the presence of β-H, and the reactions using long chain alkyl zinc reagents gave the cross-coupling product in excellent yields and selectivities. Copyright
- Zhao, Yingsheng,Wang, Haibo,Hou, Xiaohui,Hu, Yanhe,Lei, Aiwen,Zhang, Heng,Zhu, Lizheng
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p. 15048 - 15049
(2007/10/03)
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- Synthesis of naphthalenes and 2-naphthols by the electrophilic cyclization of alkynes
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A wide variety of substituted naphthalenes are readily prepared regioselectively under mild reaction conditions by the 6-endo-dig electrophilic cyclization of appropriate arene-containing propargylic alcohols by IC1, I 2, Br2, NBS, and PhSeBr. 3-Iodo-2-naphthols have also been prepared in excellent yields by the cyclization of analogous 1-aryl-3-alkyn-2-ones. This methodology readily accommodates various functional groups and has been successfully extended to the synthesis of substituted carbazoles and dibenzothiophenes.
- Zhang, Xiaoxia,Sarkar, Sampa,Larock, Richard C.
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p. 236 - 243
(2007/10/03)
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- Ligand exchange reaction of sulfoxides in organic synthesis: A novel method for synthesizing acetylenes and allenes from carbonyl compounds through sulfoxides having a trifluoromethanesulfonyloxy group on the β-carbon
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A novel method for synthesizing acetylenes and allenes from carbonyl compounds is described. Ligand exchange reaction of alkenylsulfoxides having a trifluoromethanesulfonyloxy group on the β-carbon, which were derived from α-alkyl β-ketosulfoxides, with n
- Satoh, Tsuyoshi,Itoh, Norifumi,Watanabe, Shizue,Koike, Hirofumi,Matsuno, Haruko,Matsuda, Kenji,Yamakawa, Koji
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p. 9327 - 9338
(2007/10/02)
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- Ligand Exchange Reaction of Sulfoxides in Organic Synthesis. A Novel Method for Synthesizing Acetylenes from Carbonyl Compounds through β-Trifluoromethanesulfonyloxy Vinyl Sulfoxides
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α-Sulfinyl ketones were prepared by the reaction of alkyl phenyl sulfoxide or chloromethyl p-tolyl sulfoxide with aldehydes or methyl esters in high yields, and were converted to acetylenes through β-trifluoromethanesulfonyloxy vinyl sulfoxides by the lig
- Satoh, Tsuyoshi,Itoh, Norifumi,Watanabe, Shizue,Matsuno, Haruko,Yamakawa, Koji
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p. 567 - 570
(2007/10/02)
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