21788-35-2Relevant academic research and scientific papers
Stereoselective synthesis of (2Z)-α-bromo-α,β-unsaturated esters via arsonium ylide
Huang, Zhi-Zhen,Wu, Lu-Ling,Zhu, Liu-Shen,Huang, Xian
, p. 677 - 682 (1996)
(2Z)-α-Bromo-α,β-unsaturated esters 6 can be synthesized stereo-selectively via arsonium ylides in good yields.
Visible light-mediated metal-free double bond deuteration of substituted phenylalkenes
Iakovenko, Roman,Hlavá?, Jan
supporting information, p. 440 - 446 (2021/01/28)
Various bromophenylalkenes were reductively photodebrominated by using 1,3-dimethyl-2-phenyl-1H-benzo-[d]imidazoline (DMBI) and 9,10-dicyanoanthracene. With deuterated DMBI analogs (the most effective was DMBI-d11), satisfactory to excellent isotopic yields were obtained. DMBI-d11 could also be regenerated from the reaction mixtures with a recovery rate of up to 50%. The combination of the photodebromination reaction with conventional methods for bromoalkene synthesis enables sequential monodeuteration of a double bond without the necessity of a metal catalyst. This journal is
A new convenient synthetic route towards 2-(hetero)aryl-substituted thieno[3,2-b]indoles using Fischer indolization
Irgashev, Roman A.,Steparuk, Alexander S.,Rusinov, Gennady L.
supporting information, p. 4821 - 4832 (2018/07/15)
A number of 2-(hetero)aryl-substituted thieno[3,2-b]indoles have been successfully prepared using an efficient transition-metal-free strategy, involving the Fiesselmann synthesis of methyl 5-(hetero)aryl-3-hydroxythiophene-2-carboxylates from 2-bromo-3-(hetero)arylacrylates and methyl thioglycolate, and the transformation of the synthesized 3-hydroxyesters into the corresponding thiophen-3(2H)-ones, followed by their treatment with arylhydrazines to directly form the targeted structures via Fischer indolization. At the same time, structural variety of the obtained thieno[3,2-b]indoles has been achieved due to a wide range of available starting materials, including both 2-bromo-3-(hetero)arylacrylates and arylhydrazines. In addition, two π-extended molecules, namely 1,4-bis(4H-thieno[3,2-b]indol-2-yl)benzene and 2,5-bis(4H-thieno[3,2-b]indol-2-yl)thiophene, have been synthesized in line with the current approach towards 2-(hetero)arylated thieno[3,2-b]indoles.
A substrate-driven approach to determine reactivities of α,β-unsaturated carboxylic esters towards asymmetric bioreduction
Tasnádi, Gábor,Winkler, Christoph K.,Clay, Dorina,Sultana, Nargis,Fabian, Walter M. F.,Hall, Mélanie,Ditrich, Klaus,Faber, Kurt
supporting information; experimental part, p. 10362 - 10367 (2012/10/08)
The degree of C=C bond activation in the asymmetric bioreduction of α,β-unsaturated carboxylic esters by ene-reductases was studied, and general recommendations to render these "borderline-substrates" more reactive towards enzymatic reduction are proposed. The concept of "supported substrate activation" was developed. In general, an additional α-halogenated substituent proved to be beneficial for enzymatic activity, whereas β-alkyl or β-aryl substituents were detrimental for the reactivity of nonhalogenated substrates, and α-cyano groups showed little effect. The alcohol moiety of the ester functionality was found to have a strong influence on the reaction rate. Overall, activities were determined by both steric and electronic effects. Biotransformation: The asymmetric bioreduction of α,β-unsaturated carboxylic esters by ene-reductases could be tuned by varying the degree of C=C bond activation (see scheme). An additional α-halogenated substituent proved to be beneficial for enzymatic activity, whereas β-alkyl or β-aryl substituents were detrimental for the reactivity of nonhalogenated substrates. Copyright
A novel and convenient protocol for synthesis of a-haloacrylates
Biao, Jiang,Ying, Dou,Xiangya, Xu,Min, Xu
, p. 593 - 596 (2008/04/12)
A novel and convenient protocol for synthesis of a-haloacrylates starting from phosphonium ylide and aldedyde or alcohol was described. Halodimethylsulfonium halide was used for the first time in halogenation of phosphonium ylide. Good yield as well as a
A thermal cascade route to pyrroloisoindolone and pyrroloimidazolones
McNab, Hamish,Tyas, Richard G.
, p. 8760 - 8769 (2008/03/13)
(Chemical Equation Presented) Flash vacuum pyrolysis (FVP) of indol-1-ylacrylate derivatives 11 and 15 or the isomeric indol-3-ylacrylates 21, 22, and 24 at 925°C (0.05 Torr) provides pyrrolo[1,2-a]indol-3-ones 2, 18, 28, and 29 in 53-90% yield by a cascade mechanism that involves a sigmatropic migration, elimination, electrocyclization sequence. Pyrrolo[1,2-a]imidazol-5- ones 3 and pyrrolo[1,2-c]imidazol-5-ones 4 were similarly obtained by FVP of corresponding 2,5-unsubstituted imidazol-1-ylacrylates (e.g., 33), with the former isomer predominating in ca. 80:20 ratio. Migration to the 2-position is therefore favored in the initial sigmatropic shift. FVP of 2-substituted imidazol-1-ylacrylates 35, 37, and 51 (825-875°C) instead give pyrrolo[1,2-c]imidazol-5-ones 56-58 only (88-91%), and that of 4,5-disubstituted imidazol-1-ylacrylates 39 and 41 (825-850°C) provide pyrrolo[1,2-a] imidazol-5-ones 59 and 60 exclusively (93-95%), and thus the selectivity of the initial shift can be controlled by the presence of substituents on the imidazole 2- and 5-positions. FVP of the benzimidazole analogues 61 and 62 at 950°C gave the pyrrolo[1,2-a]benzimidazol-1-ones 6 (71%) and 63 (36%), respectively.
Fe(0)-mediated synthesis of tri- and tetra-substituted olefins from carbonyls: An environmentally friendly alternative to Cr(II)
Falck,Bejot, Romain,Barma, Deb K.,Bandyopadhyay, Anish,Joseph, Suju,Mioskowski, Charles
, p. 8178 - 8182 (2007/10/03)
Fe(0) was investigated as a cost-effective, environmentally friendly alternative to Cr(II) for the olefination of carbonyls by activated polyhalides. In many instances, Fe(0) was equivalent or superior to Cr(II). Notably, Fe(0), but not Cr(II), proved com
Highly selective reaction of α-halo-αβ-unsaturated esters with ketones or aldehydes promoted by SmI2: An efficient alternative access to Baylis-Hillman adducts
Concellon, Jose M.,Huerta, Monica
, p. 4714 - 4719 (2007/10/03)
A samarium diiodide promoted addition of aromatic or aliphatic β-substituted-α-halo-α,β-unsaturated esters 1 or 3 to both ketones (in THF) and aldehydes (in acetonitrile) led to (Z)-2-(1-hydroxyalkyl)- 2,3-alkenoates 2 and 4 in good yields and very high stereoselectivity. This method constitutes an efficient and valuable alternative to the synthesis of Baylis-Hillman adducts. A mechanism is proposed to explain this transformation.
Bis(2,2,2-trifluoroethyl)bromophosphono-acetate, a novel HWE reagent for the preparation of (E)-α-bromoacrylates: A general and stereoselective method for the synthesis of trisubstituted alkenes
Tago, Keiko,Kogen, Hiroshi
, p. 1975 - 1978 (2007/10/03)
(Equation presented) A novel reagent, methyl bis(2,2,2-trifluoroethoxy)bromophosphonoacetate (3a), was designed and prepared in order to efficiently synthesize (E)-α-bromoacrylates, which are useful precursors for various C-C bond formations. Honer-Wadswo
A Rapid Synthesis of Aziridine Derivatives over Bentonite in 'Dry Media'
Saoudi, Aicha,Hamelin, Jack,Benhaoua, Hadj
, p. 492 - 493 (2007/10/03)
Functionalized aziridines are synthesized from dibromo compounds and primary aliphatic amines in the absence of solvent over bentonite as a solid support; in some examples microwave activation is compared to normal heating.
