147795-77-5Relevant academic research and scientific papers
TsNBr2 promoted decarboxylative bromination of α,β-unsaturated carboxylic acids
Hazarika, Debojit,Phukan, Prodeep
, p. 4593 - 4596 (2018)
A rapid process for decarboxylative bromination of α,β-unsaturated carboxylic acids have been developed using N,N-dibromo-p-toluenesulfonamide (TsNBr2). Treatment of cinnamic acids with TsNBr2 in presence of potassium carbonate in acetonitrile produces corresponding β-bromostyrenes at room temperature. Exclusive formation of (E)-β-bromostyrenes was observed in a stereoselective manner within a very short period of time (5–15 min). This method was further extended for obtaining 1-bromoalkynes from corresponding propiolic acids. Instantaneous formation of bromoalkynes was observed when the reaction was carried out in presence of DBU as a base in acetonitrile at room temperature. A wide variety of cinnamic acids and propiolic acids could be converted to corresponding β-bromostyrenes and 1-bromoalkynes respectively under mild reaction condition with high to excellent yield.
Method for preparing 1-halogenated alkyne under catalysis of heterogeneous Ag catalyst at room temperature
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Paragraph 0047; 0049, (2021/05/12)
The invention discloses a novel method for preparing 1-halogenated alkyne under the catalysis of a heterogeneous Ag catalyst at room temperature. The method comprises the steps of mixing terminal alkyne compounds containing different substituent groups, N
Regio- and Stereoselective N-addition to an Open Bromo Vinyl Cation
Chuchmareva, Marina,Collong, Arndt,Niggemann, Meike,Schr?der, Sebastian,Strauch, Christina
supporting information, (2021/06/07)
A protocol for the synthesis of thus far inaccessible bromo vinyl triflimides is presented. Our previously reported concept of assisted vinyl cation formation was engaged to achieve both a protonation of relatively electron poor bromo alkynes and a reaction with high regio- and stereoselectivity. To the best of our knowledge, this is the first stereoselective addition of an N-nucleophile to an open β-halovinyl cation.
Visible-Light-Promoted Formation of C—C and C—P Bonds Derived from Evolution of Bromoalkynes under Additive-Free Conditions: Synthesis of 1,1-Dibromo-1-en-3-ynes and Alkynylphosphine Oxides
Xu, Hailong,Chen, Rui,Ruan, Hongjie,Ye, Ruyi,Meng, Ling-Guo
supporting information, p. 873 - 878 (2021/03/04)
The controllable achievement of C—C and C—P bond formations is developed via visible-light-promoted bromoalkyne dimerization or its further transformation with secondary phosphine oxides. The 1,1-dibromo-1-en-3-ynes are formed when bromoalkyne is exposed to visible-light. While alkynylphosphine oxides are generated when bromoalkynes are mixed with secondary phosphine oxides.
Synthesis of fluoroalkylated alkynes: Via visible-light photocatalysis
Iqbal, Naila,Iqbal, Naeem,Han, Sung Su,Cho, Eun Jin
supporting information, p. 1758 - 1762 (2019/02/20)
Fluoroalkylated alkynes, which are versatile building blocks for the synthesis of various biologically active organofluorine compounds, were synthesized from easily available alkynyl halides and fluoroalkyl halides by visible-light photocatalysis. Addition of fluoroalkyl radicals to alkynes and subsequent dehalogenation selectively yielded fluoroalkylated alkynes.
Highly efficient and recyclable catalyst for the direct chlorination, bromination and iodination of terminal alkynes
Shi, Wei,Guan, Zhipeng,Cai, Peng,Chen, Hao
, p. 199 - 204 (2017/08/10)
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.
Cobalt(II)-catalyzed electrophilic alkynylation of 1,3-dicarbonyl compounds to form polysubstituted furans via π-π Activation
Roslan, Irwan Iskandar,Sun, Jiulong,Chuah, Gaik-Khuan,Jaenicke, Stephan
supporting information, p. 719 - 726 (2015/03/18)
Polysubstituted furans were obtained with excellent yields via the electrophilic alkynylation of 1,3-dicarbonyl compoundsws with phenyl- or ester-substituted brominated alkynes. The reaction is catalyzed by the inexpensive and readily available catalyst, cobalt(II) chloride, and has a wide substrate scope. The C(sp)-C(sp3) coupling occurs under mild conditions with short reaction times and does not require an inert atmosphere or ligands. It is proposed that the reaction proceeds through a chelation complex of cobalt(II) with the deprotonated 1,3-dicarbonyl compound.
Synthesis and Physical Properties of Asymmetric Diphenyldiacetylenic Liquid Crystals
Meng, H.-H. B.,Dalton, L. R.,Wu, S.-T.
, p. 303 - 314 (2007/10/02)
Fifty-six asymmetric diphenyl-diacetylene liquid crystal homologs including dialkyl, alkyl-alkoxy, cyano-alkyl, chloro-alkyl, fluoro-alkyl, difluoro-alkyl, lateral chloro-substituted fluoro-alkyl (or alkoxy), lateral fluoro-substituted asymmetric dialkyl, and vinyl-alkyl are synthesized and their physical properties evaluated.Among these asymmetric diphenyl-diacetylene liquid crystals, many dialkyl homologs exhibit low melting point, wide nematic range, and low heat of fusion.They are ideal host candidates for formulating eutectic mixtures.The polar groups make important contributions to the phase transition temperature, dielectric anisotropy, refractive indices and viscosity.Detailed effects depend on the position of the substitution.These new liquid-crystals compounds and mixtures are particularly useful for electro-optic modulation of infrared radiation. - Keywords: Diphenyl-diacetylenes, eutectic mixtures, electro-optic modulation, physical properties
