59106-34-2Relevant academic research and scientific papers
Stereoselective Halo-Succinimide Facilitated α-Halogenations of Substituted α-Trialkylsilyl-β-Substituted-α,β-Unsaturated Esters
Jennings, Michael P.,Probasco, Kristina C.
, p. 8945 - 8954 (2021/07/20)
The NXS (X = Cl, Br)-mediated halogenation of a series of (E)-α-trimethylsilyl-β-alkyl(aryl)-α,β-unsaturated esters in dimethylformamide (DMF) has furnished (Z)-β-substituted-α-halogenated-α,β-unsaturated ester products in moderate to high isolated yields (58-90%) with dr values of >20:1 coupled with the inversion of olefin stereochemistry. The reaction process was hypothesized to include an initial halonium cation intermediate, followed by regioselective ring opening with DMF. Subsequentanti-E2-type concomitant elimination allowed for the stereoselective formation of the product vinylic bromo-and chloroesters.
Transition metal-free diastereospecific synthesis of (Z)-2-arylidene-2,3-dihydrobenzo[b][1,4]dioxines by reaction of (Z)-1,2-dibromo-3-aryl-2-propenes with catechols
Beifuss, Uwe,Bharatam, Prasad V.,Conrad, Jürgen,Frey, Wolfgang,Rekowski, Szymon P.,Wani, Aabid A.
, (2020/09/18)
A transition metal-free, diastereospecific reaction between substituted (Z)-1,2-dibromo-3-phenyl-2-propenes and substituted catechols using Cs2CO3 as a base at 140 °C for 18 h delivers exclusively substituted (Z)-2-arylidene-2,3-dihy
A process for synthesizing substituted α α -, β - unsaturated carboxylic acid ester compound and its preparation and application method
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Paragraph 0040-0043, (2017/08/25)
The invention belongs to the technical field of organic synthesis, and particularly relates to an alpha-diphenylphosphinesubstituted alpha, beta-unsaturated carboxylatecompound as well as preparation and application methods. A simple reagent phosphorus ylide and aromatic aldehyde are taken as raw materials, a Wittig reactionand a phosphorus ylidereaction of carboxylate ester are performed, a halogenating agent is added, halogenated alpha, beta-unsaturated carboxylate ester is generated and reacts with diphenylphosphine under catalysis of a palladium reagent, and a target product with high yield is generated. Carboxylate of the compound can be transformed into other groups, so that a novel organicphosphine catalyst is generated.
Visible light photoredox catalyzed cascade cyclizations of α-bromochalcones or α-bromocinnamates with heteroarenes
Paria, Suva,Reiser, Oliver
supporting information, p. 557 - 562 (2014/05/20)
Vinyl radicals were generated from α-bromochalcones or a-bromocinnamate ethyl ester under visible light photoredox catalyzed conditions via an oxidative quenching cycle of the iridium complex [Ir{d(CF 3)ppy}2(dtbbpy)]PF6 and subjected to cascade cyclizations with heteroarenes entailing two consecutive C-C bond formations and three C-H activations. The process is amenable to furans, benzofurans, pyrroles, and indoles, giving rise to a broad variety of novel polycyclic frameworks in high yields under mild and environmentally benign reaction conditions.
Synthesis, characterization, and catalytic activity of ionic liquids based on biosources
Moriel,García-Suárez,Martínez,García,Montes-Morán,Calvino-Casilda,Ba?ares
supporting information; experimental part, p. 4877 - 4881 (2010/10/02)
New room-temperature ionic liquids were synthesized from natural and easily available feedstocks (choline hydroxide and amino acids) following an economical and green route in which the only by-product was water. They were successfully applied as catalyst
A facile one-pot synthesis of α-bromo-α,β-unsaturated esters from alcohols
Karama, Usama,Al-Othman, Zeid,Al-Majid, Abdullah,Almansour, Abdulrahman
experimental part, p. 3276 - 3280 (2010/09/05)
Treatment of N-bromosuccinimide (NBS) with (carboethoxymethylene) triphenylphosphorane (1) in CH2Cl2 followed by the addition of an alcohol in the presence of manganese dioxide under ultrasonic irradiation constitutes a stereoselective one-pot procedure for the preparation of Z-configured α-bromo-α,β-unsaturated esters in good to excellent yield.
Simple and efficient copper-catalyzed approach to 2,4-disubstituted imidazolones
Gong, Xiaoyu,Yang, Haijun,Liu, Hongxia,Jiang, Yuyang,Zhao, Yufen,Fu, Hua
supporting information; experimental part, p. 3128 - 3131 (2010/09/04)
(Figure Presented) Some imidazolone derivatives are biological and pharmaceutical active molecules and the chromophores of the fluorescent proteins. In this communication, a simple and efficient approach to 4-arylidene-2-alkyl-4,5-dihydro-1H-imidazol-5-ones (2,4-disubstituted imidazolones) has been developed, and the protocol uses readily available 2-bromo-3-alkylacrylic acids and amidines as the starting materials without addition of any ligand or additive. The reactions were performed under mild conditions. Therefore, the present method will be of wide application in organic chemistry and medicinal chemistry.
A convenient method for the synthesis of (Z)-α-haloacrylates: Lewis base-catalyzed carbonyl olefination using α-halo-C,O-bis(trimethylsilyl)ketene acetals
Michida, Makoto,Toriumi, Takako,Mukaiyama, Teruaki
experimental part, p. 3261 - 3262 (2009/08/09)
A highly useful method for the stereoselective synthesis of (Z)-α-haloacrylates from various aldehydes that uses α-halogenated ethyl-C,O-bis(trimethylsilyl)ketene acetals in the presence of a Lewis base catalyst such as acetate salts was established. This
79Br NMR spectroscopy as a practical tool for kinetic analysis
Chan, Si Jia,Howe, Andrew G.,Hook, James M.,Harper, Jason B.
experimental part, p. 342 - 347 (2010/02/27)
79Br NMR spectroscopy has been used to monitor a series of reactions in which the bromide ion is produced, including the Menschutkin reaction of pyridine with a range of substituted benzyl bromides and a Heck coupling process. In cases where the process could also be monitored using 1H NMR spectroscopy, the kinetic analyses using heteronuclear magnetic resonance spectroscopy were shown to be completely consistent. Both the utility of the process in following reactions which may be difficult to analyse using other techniques and the practical limitations associated with solvent choice are discussed. Copyright
Preparation of α-bromoacrylates: One-pot procedure for the synthesis of conjugated acetylenic carboxylates from aldehydes with Ph3P/ Br3CCO2Et
Kim, Joong-Gon,Dong, Ho Kang,Doo, Ok Jang
, p. 443 - 447 (2008/04/01)
We have established the optimal conditions for the Wittig reaction for synthesizing α-bromoacrylates with a high selectivity, and developed a simple and efficient one-pot procedure for preparing various conjugated acetylenic carboxylates in moderate to high yields. Georg Thieme Verlag Stuttgart.
