21788-36-3Relevant academic research and scientific papers
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
One-pot and regioselective synthesis of functionalized γ-lactams via a metal-free sequential Ugi 4CR/Intramolecular 5-exo-dig cyclization reaction
Yan, Yan-Mei,Wang, Meng-Liang,Liu, Yu-Long,He, Ying-Chun
, (2020/07/24)
A new one-pot and regioselective synthesis of functionalized γ-lactams by a metal-free Ugi 4CR/intramolecular 5-exo-dig cyclization sequence under mild conditions has been developed. The reaction of propenoic acids, aldehydes, amines, and isocyanides produced γ-lactams regioselectively in 72–89percent yields via sequential Ugi 4CR/intramolecular 5-exo-dig cyclization reaction in the presence of Cs2CO3.
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.
Titanium mediated olefination of aldehydes with α-haloacetates: An exceptionally stereoselective and general approach to (Z)-α-haloacrylates
Augustine, John Kallikat,Bombrun, Agnes,Venkatachaliah, Srinivasa,Jothi, Anandh
, p. 8065 - 8072 (2013/12/04)
An exceptionally stereoselective and general synthesis of (Z)-α-haloacrylates, ready to undergo various synthetic transformations, has been demonstrated from α-haloacetates and aldehydes in a one-pot manner via the titanium-enolate based asymmetric aldol
Ru-catalyzed highly chemo- and enantioselective hydrogenation of γ-halo-γ,δ-unsaturated-β-keto esters under neutral conditions
Ma, Xin,Li, Wanfang,Li, Xiaoming,Tao, Xiaoming,Fan, Weizheng,Xie, Xiaomin,Ayad, Tahar,Ratovelomanana-Vidal, Virginie,Zhang, Zhaoguo
supporting information; experimental part, p. 5352 - 5354 (2012/06/30)
Finely-tuned ruthenium-catalyzed highly chemoselective and enantioselective hydrogenation of γ-halo-γ,δ-unsaturated-β-keto esters at the carbonyl group was achieved under neutral reaction conditions (ee up to 97%). Both olefin and alkenyl halogen moieties, which are labile under hydrogenation conditions, remained untouched during the reaction.
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
Biocatalyzed enantioselective reduction of activated C=C bonds: Synthesis of enantiomerically enriched α-halo-β-arylpropionic acids
Brenna, Elisabetta,Gatti, Francesco G.,Manfredi, Alessia,Monti, Daniela,Parmeggiani, Fabio
experimental part, p. 4015 - 4022 (2011/09/15)
The enantioselective biocatalyzed reduction of the C=C bond of some (Z)-methyl α-halo-β-arylacrylates was investigated. The reaction was performed by baker's yeast fermentation and Old Yellow Enzymes 1-3 mediated biotransformations. The final products wer
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
