5369-55-1Relevant academic research and scientific papers
Me3SiBr-mediated intramolecular cyclization of γ-functionalized trimethylsilyl nitronates
Tishkov, Alexander A.,Kozintsev, Anton V.,Lyapkalo, Il'ya M.,Ioffe, Sema L.,Kachala, Vadim V.,Strelenko, Yuri A.,Tartakovsky, Vladimir A.
, p. 5075 - 5078 (1999)
The silylation of nitro compounds of general formula X1X2CHCH(Ar)CH2NO2 with Me3SiBr/Et3N at -30°C leads to hitherto unknown 2-(N,N'-bis(trimethylsilyloxy)amino-2,3-dihydrofurans (X1/
Synthesis of new antineoplastic agents based on imidazo[2,1-a]pyridine
Brovarets, Volodymyr S.,Potikha, Lyudmila M.
, p. 1460 - 1464 (2020)
[Figure not available: see fulltext.] 2-Aryl-2-(2-aryl-2-oxoethyl)-1H,2H,3H-imidazo[1,2-a]pyridin-4-ium bromides were obtained in the reaction of (2Z)-4-bromo-1,3-diphenylbut-2-en-1-one derivatives with 2-aminopyridines in benzene. The effect of the structure of the starting reagents on the results of the reactions was studied. Antitumor activity of 2-(4-chlorophenyl)-2-[2-(4-chlorophenyl)-2-oxoethyl]-1H,2H,3H-imidazo[1,2-a]pyridin-4-ium bromide was determined, which showed high antitumor potential of the test compound on 60 human cancer cell lines.
CATALYTIC METHOD OF SYNTHESIS OF 2,4-DIPHENYLFURAN AND 2-PHENYLINDOLE
Anisimov, B. N.,Obynochnyi, A.A.,Prostakov, N. S.
, p. 297 - 298 (1992)
2,4-Diphenylfuran has been obtained from acetophenone and its mixture with aniline, over K-16 catalyst.It has been established that the reaction proceeds through a stage of dypnone formation.When the aniline-acetophenone mixture is used as the starting material, small amounts of 2-phenylindole are formed.
β-Bromoenol phosphate as a new precursor for the modular regioselective synthesis of substituted furans
Fernandes, Rushil,Mhaske, Krishna,Narayan, Rishikesh
, (2021/11/24)
Owing to its importance in various realms of chemistry, furan occupies a position of eminence among heterocycles. Despite the availability of many methodologies for the synthesis of variably substituted furans, a modular convenient synthesis of 2,4-disubstituted furans remains challenging. The present work attempts to bridge that gap through a novel annulation-based approach using feedstock chemicals such as methyl ketones and their easily available derivatives, β-bromoenol phosphates. We have demonstrated a hitherto unknown reactivity of β-bromoenol phosphates which is responsible for the observed regioselectivity. The reaction requires only sodium hydride as the base under mild conditions. The scope of the reaction was found to be broad with the possibility of obtaining even tri-substituted furans besides a variety of 2,4-disubstituted furans. The methodology was applied to obtain synthetically challenging 3-acylfuran derivatives as well. The newly developed methodology is characterized by the modularity, regioselectivity as well as its practicality owing to easily available starting materials and fast reaction times.
Access to Benzylic Quaternary Carbons from Aromatic Ketones
Li, You,Han, Jingpeng,Luo, Han,An, Qiaoyu,Cao, Xiao-Ping,Li, Baosheng
supporting information, p. 6050 - 6053 (2019/08/26)
The construction of benzylic all-carbon quaternary stereocenters, which are ubiquitous in biomolecules and drugs, is a task of high practical significance. Herein, we disclose a highly efficient one-pot method of constructing all-carbon quaternary structu
Asymmetric hydrogenation of furans and benzofurans with iridium-pyridine-phosphinite catalysts
Pauli, Larissa,Tannert, Re,Scheil, Robin,Pfaltz, Andreas
supporting information, p. 1482 - 1487 (2015/01/30)
Enantioselective hydrogenation of furans and benzofurans remains a challenging task. We report the hydrogenation of 2- and 3-substituted furans by using iridium catalysts that bear bicyclic pyridine-phosphinite ligands. Excellent enantioselectivities and high conversions were obtained for monosubstituted furans with a 3-alkyl or 3-aryl group. Furans substituted at the 2-position and 2,4-disubstituted furans proved to be more difficult substrates. The best results (80-97% conversion, 65-82% enantiomeric excess) were obtained with monosubstituted 2-alkylfurans and 2-[4-(trifluoromethyl)phenyl]furan. Benzofurans with an alkyl substituent at the 2- or 3-position also gave high conversions and enantioselectivity, whereas 2-aryl derivatives showed essentially no reactivity. The asymmetric hydrogenation of a 3-methylbenzofuran derivative was used as a key step in the formal total synthesis of the cytotoxic naphthoquinone natural product (-)-thespesone.
Suzuki-Miyaura cross-coupling reaction of 1,2-oxaborol-2(5H)-ols with carboxylic anhydrides: A new method to furans
Yu, Tao,Wu, Xin-Yan,Yang, Jun
supporting information, p. 4071 - 4074 (2014/07/22)
An efficient one-step method has been developed to construct furans via a Suzuki-Miyaura cross-coupling reaction of 1,2-oxaborol-2(5H)-ols with carboxylic anhydrides. In the presence of Pd(OAc)2/PCy3, the multi-substituted alkenylboron compounds could couple with anhydrides to obtain furans in moderate-to-good yields. The addition of bases promoted the coupling reaction, and the plausible reaction mechanism was proposed.
Catalytic activation of carbohydrates as formaldehyde equivalents for stetter reaction with enones
Zhang, Junmin,Xing, Chong,Tiwari, Bhoopendra,Chi, Yonggui Robin
supporting information, p. 8113 - 8116 (2013/07/19)
We disclose the first catalytic activation of carbohydrates as formaldehyde equivalents to generate acyl anions as one-carbon nucleophilic units for a Stetter reaction. The activation involves N-heterocyclic carbene (NHC)-catalyzed C-C bond cleavage of carbohydrates via a retro-benzoin-type process to generate the acyl anion intermediates. This Stetter reaction constitutes the first success in generating formal formaldehyde-derived acyl anions as one-carbon nucleophiles for non-self-benzoin processes. The renewable nature of carbohydrates, accessible from biomass, further highlights the practical potential of this fundamentally interesting catalytic activation.
Poly(ethylene glycol) as a reaction matrix in platinum- or gold-catalyzed cycloisomerization: A mechanistic investigation
Spina, Rosella,Colacino, Evelina,Martinez, Jean,Lamaty, Frédéric
supporting information, p. 3817 - 3821 (2013/04/24)
Design for diversity: A new catalytic system based on PEG-3400 and a metal salt (Pt or Au) was designed to efficiently perform a cycloisomerization reaction under microwave irradiation, which gave diverse heterocycles in good to excellent yields, after a
Copper-catalyzed synthesis of substituted furans and pyrroles by heterocyclodehydration and tandem heterocyclodehydration-hydration of 3-yne-1,2-diols and 1-amino-3-yn-2-ol derivatives
Gabriele, Bartolo,Veltri, Lucia,Plastina, Pierluigi,Mancuso, Raffaella,Vetere, Mabel V.,Maltese, Vito
, p. 4919 - 4928 (2013/07/05)
CuCl2-catalyzed heterocyclodehydration of readily available 3-yne-1,2-diols and 1-amino-3-yn-2-ol derivatives afforded substituted furans and pyrroles, respectively, in good to high yields (53-99%) under mild conditions (MeOH as the solvent, 80-100 °C, 1-24 h). In the case of 2,2-dialkynyl-1,2-diols, bearing an additional alkynyl substituent at C-2, a cascade process, corresponding to copper-catalyzed heterocyclodehydration followed by acid-catalyzed hydration of the triple bond, was realized when the reaction was carried out in the presence of both CuCl2 and TsOH, leading to 3-acylfurans in one step and high yields (75-84%). Under the same conditions, N-Boc-2-alkynyl-1-amino-3-yn-2-ols were converted into the corresponding N-unsubstituted 3-acylpyrroles in low to fair yields (19-59%). However, working in the presence of added water and a large excess of CO 2 (40 atm), in addition to CuCl2 and TsOH, caused a significant improvement of the yields of 3-acylpyrroles (68-87%), thus making the method of general synthetic applicability.
