- Chloramine Salt Mediated Oxidative Halogenation of Terminal Alkynes with KI or NaBr: Practical Synthesis of 1-Bromoalkynes and 1-Iodoalkynes
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A direct oxidative halogenation of terminal alkynes has been realized using chloramine-B as the oxidant and KI or NaBr as the halogen source. This reaction enables a general and practical access to synthetically valuable 1-bromoalkynes and 1-iodoalkynes i
- Liu, Xiaozu,Chen, Guojun,Li, Chenglong,Liu, Peijun
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- DBU/DMSO Promoted Dehydrobromination of 1,1-Dibromoolefins. A General Synthesis of 1-Bromoaromatic Alkynes under mild Conditions
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A new procedure for the synthesis of 1-bromoalkynes by DMSO/DBU induced dehydrobromination of 1,1-dibromoethylenes under mild conditions is described.
- Ratovelomanana, Victorin,Rollin, Yolande,Gebehenne, Catherine,Gosmini, Corinne,Perichon, Jacques
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- Palladium-Catalyzed Carbonylation in the Synthesis of N-Ynonylsulfoximines
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Palladium-catalyzed carbonylation reactions with Cr(CO)6 as carbonyl source are key for the preparation of N-ynonylsulfoximines from NH-sulfoximines and bromoalkynes. The couplings proceed at room temperature with a wide range of substrate combinations affording the corresponding products in good yields. (Figure presented.).
- Ma, Ding,Wang, Chenyang,Kong, Deshen,Tu, Yongliang,Shi, Peng,Bolm, Carsten
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supporting information
p. 1330 - 1334
(2021/01/26)
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- Nickel-Catalyzed Reductive 1,2-Dialkynylation of Alkenes Bearing an 8-Aminoquinoline Directing Group
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An unprecedented nickel-catalyzed reductive 1,2-dialkynylation of alkenes bearing an 8-aminoquinoline directing group has been developed. This method proceeded through a migratory insertion/reductive-coupling process under mild conditions with a wide substrate scope and good functional group tolerance, providing direct access to the synthetically flexible 1,5-diynes. Moreover, the 1,2-dialkynylation products could be further converted to borate-ester- or azide-functionalized 1,5-dienes, ditriazole, β-diyne primary amide, and trisubstituted benzene.
- Pan, Rui,Shi, Cong,Zhang, Dongquan,Tian, Yang,Guo, Songjin,Yao, Hequan,Lin, Aijun
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supporting information
p. 8915 - 8920
(2019/11/14)
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- Highly efficient and recyclable catalyst for the direct chlorination, bromination and iodination of terminal alkynes
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Direct halogenation, including chlorination, bromination and iodination of terminal alkynes, are of great importance in organic synthesis. Here an efficient and recyclable nano-Ag/g-C3N4 catalyst system was developed and proved to be remarkably active with 39 examples varied from chlorination, bromination to iodination, of which 14 runs have yielded more than 95% of the product. Recycling of the catalyst was also achieved without obvious activity loss after several runs: 99% yield was observed even after 5 runs in the bromination of phenylacetylene. The catalysts system is of low cost and easy to be prepared, making this procedure versatile, convenient and economic.
- Shi, Wei,Guan, Zhipeng,Cai, Peng,Chen, Hao
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p. 199 - 204
(2017/08/10)
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- Csp-Csp3 Bond Formation via Iron(III)-Promoted Hydroalkynylation of Unactivated Alkenes
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An iron(III)-promoted hydroalkynylation of unactivated alkenes toward Csp-Csp3 bond formation has been developed. Various alkenes, including mono-, di-, and trisubstituted alkenes, could all smoothly convert to structural diversified alkynes in this chemoselective protocol. Additionally, the scalability was unraveled and the further divergent transformations of products were conducted to demonstrate the synthetic utility.
- Shen, Yangyong,Huang, Bo,Zheng, Jing,Lin, Chen,Liu, Yu,Cui, Sunliang
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supporting information
p. 1744 - 1747
(2017/04/11)
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- Regioselective Synthesis of 5-Aminooxazoles via Cp?Co(III)-Catalyzed Formal [3 + 2] Cycloaddition of N-(Pivaloyloxy)amides with Ynamides
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A simple and efficient protocol for the regioselective synthesis of 5-aminooxazoles is disclosed. The reaction, catalyzed by a cheap Cp?Co(III) catalyst, starts from easily accessible N-(pivaloyloxy)amides and ynamides. Mild reaction conditions, a broad s
- Han, Xiang-Lei,Zhou, Chu-Jun,Liu, Xu-Ge,Zhang, Shang-Shi,Wang, Honggen,Li, Qingjiang
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supporting information
p. 6108 - 6111
(2017/11/27)
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- Controlled Reactivity of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) in the Selective Synthesis of 1-(Bromoethynyl)arenes
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The nucleophilic reactivity of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was completely controlled by the formation of monohydrate (DBU?H2O) in the synthesis of 1-(bromoethynyl)arenes from 1,1-dibromoalkenes. Differential reactivity of DBU in pr
- Krishna Moodapelly, Shiva,Sharma, Gangavaram V. M.,Ramana Doddi, Venkata
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supporting information
p. 1535 - 1540
(2017/05/05)
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- Transition-Metal Free Mechanochemical Approach to Polyyne Substituted Pyrroles
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In this contribution, the synthesis of long chain hexatriynyl- and octatetraynyl-substituted pyrroles in one step from 1-halopolyyne precursors is reported. The products were obtained via a mechanochemical approach by simple grinding of 1-haloalkynes with
- Pigulski, Bart?omiej,Arendt, Agata,Tomilin, Denis N.,Sobenina, Lyubov N.,Trofimov, Boris A.,Szafert, S?awomir
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p. 9188 - 9198
(2016/10/18)
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- Palladium end-capped polyynes via oxidative addition of 1-haloalkynes to Pd(PPh3)4
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Reported here is the use of 1-haloacetylenes and 1-halopolyynes as synthons for the preparation of new palladium(II) end-capped polyynes. The 1-haloalkynes were obtained in a series of transformations from para-substituted bromoarenes that included Sonogashira coupling followed by halogenation and chain elongation via Cadiot-Chodkiewicz protocol. The key step for the synthesis of metal complexes was oxidative addition of 1-haloalkynes to Pd(PPh3)4, which allowed obtaining a series of metal compounds 1-5-CnX with carbon chains up to hexatriyne in 75-100% yield. All the compounds were characterized by NMR and HRMS or elemental analysis. The 13C spectra of the 1-haloalkynes showed interesting, although expected, shifts of the carbon chain atoms close to the halogen termini. X-ray crystal structures were obtained for three polyynes-two butadiynes (2-C4[Pd]Br and 3-C4[Pd]Br) and one hexatriyne (1-C6[Pd]Br)-and the latter is the first reported X-ray crystal structure of palladium end-capped hexatriyne.
- Gulia, Nurbey,Pigulski, Bartlomiej,Szafert, Slawomir
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p. 673 - 682
(2015/05/12)
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- Synthesis of Long, Palladium End-Capped Polyynes through the Use of Asymmetric 1-Iodopolyynes
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The synthesis of a unique series of long, asymmetric 1-iodopolyynes (1-CnI and 2-CnI) with the sp-hybridized carbon chain up to a decapentayne is reported. These compounds were then used as substrates in reactions with Pd(PPh3/
- Pigulski, Bartlomiej,Gulia, Nurbey,Szafert, Slawomir
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p. 17769 - 17778
(2015/12/05)
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- Regio- and stereospecific synthesis of (E)-α-iodoenamide moieties from ynamides through iodotrimethylsilane-mediated hydroiodation
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A facile approach to (E)-α-haloenamide moieties from ynamides using bromo- or iodotrimethylsilane is described. The simple protocol enables a regio- and stereospecific hydrohalogenation of the triple bond in gram-scale and provides a general entry for synthesis of novel enamide analogues.
- Sato, Akihiro H.,Ohashi, Kazuhiro,Iwasawa, Tetsuo
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supporting information
p. 1309 - 1311
(2013/03/13)
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- Regio- and stereoselective synthesis of 1-(1-halovinyl)-1H-indoles from 1-ethynyl-1H-indoles with in situ generated HX
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A facile approach to 1-(1-halovinyl)-1H-indoles from readily accessible 1-ethynyl-1H-indoles with in situ generated HX is described. The simple protocol enables a regio- and stereoselective hydrohalogenation to the triple bonds in gram-scale, and provides a general entry for novel N-alkenylindole derivatives.
- Sato, Akihiro H.,Ohashi, Kazuhiro,Ito, Kouhei,Iwasawa, Tetsuo
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supporting information
p. 2878 - 2881
(2013/06/26)
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- Synthesis of heteroaryl ketones via tandem reaction of 1,1-dibromoethenes
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A novel method for the synthesis of heteroaryl ketones through one-pot tandem reaction of 1,1-dibromoethenes with 2-amino(thio)phenols promoted by TBAF·3H2O and RuCl3(5%)/air was developed. This novel method includes several reactions in one-pot and utilizes economical yet efficient reagents to generate synthetically and biologically interesting heteroaryl ketones under mild conditions with good efficiency.
- Fan, Xuesen,He, Yan,Zhang, Xinying,Guo, Shenghai,Wang, Yangyang
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experimental part
p. 6369 - 6374
(2011/09/12)
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- Synthesis and molecular properties of donor-π-spacer-acceptor ynamides with up to four conjugated alkyne units
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A set of push-pull ynamides with up to four conjugated triple bonds has been synthesized and the molecular properties of these new carbon rods have been characterised showing effective intramolecular charge transfers and high values for the change of the
- Witulski, Bernhard,Schweikert, Torsten,Schollmeyer, Dieter,Nemkovich, Nicolai A.
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supporting information; experimental part
p. 2953 - 2955
(2010/08/05)
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- Synthesis and Characterization of Liquid Crystalline Monomers and Side-Chain Polymers Containing Diphenyldiacetylene Mesogens
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Nine unsymmetrically diphenyldiacetylenic monomers were prepared.The phase behavior as well as thermal polymerization of the obtained monomers were characterized by optical polarizing microscopy and DSC measurement.UV absorption, refractive indices and dielectric constants of the monomers were also measured.The olefinic monomers were subjected to undergo hydrosilylation reaction with poly(methylhydrogensiloxane) to form the polysiloxanes.Thermal behavior of the prepared polysiloxanes were studied.
- Lu, Yong-Hong,Hsu, Chain-Shu,Wu, Shin-Tson
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