25354-83-0Relevant articles and documents
Synthesis and evaluation of novel α-substituted chalcones with potent anti-cancer activities and ability to overcome multidrug resistance
Riaz, Sharon,Iqbal, Maheen,Ullah, Rahim,Zahra, Rida,Chotana, Ghayoor Abbas,Faisal, Amir,Saleem, Rahman Shah Zaib
, p. 123 - 135 (2019/03/19)
A series of forty α-substituted chalcones were synthesized and screened for their antiproliferative activities against HCT116 (colorectal) and HCC1954 (breast) cancer cell lines. Compounds 5a and 5e were found to be the most potent compounds with GI5
CBr4 as a Halogen Bond Donor Catalyst for the Selective Activation of Benzaldehydes to Synthesize α,β-Unsaturated Ketones
Kazi, Imran,Guha, Somraj,Sekar, Govindasamy
supporting information, p. 1244 - 1247 (2017/03/14)
CBr4 has been employed as a halogen bond donor catalyst for the selective activation of aldehyde, to achieve an efficient solvent- and metal-free CC bond forming reaction in the presence of strong acid sensitive groups such as methoxy, cyanide, ester, and ketal for the synthesis of α,β-unsaturated ketones. This unique capability of CBr4 to act as a halogen bond donor has been explored and established using UV-vis as well as IR spectroscopy. Moreover, this unprecedented methodology enables the synthesis of the pharmaceutically important molecule licochalcone A.
Investigation of substituent effects on the selectivity of 4π-electrocyclization of 1,3-diarylallylic cations for the formation of highly substituted indenes
Smith, Chris D.,Rosocha, Gregory,Mui, Leo,Batey, Robert A.
supporting information; experimental part, p. 4716 - 4727 (2010/09/05)
(Figure Presented) Differentially substituted 1,3-diaryl-substituted allylic cations generated by ionization of the corresponding allylic alcohols in the presence of a Lewis acid undergo chemoselective and regioselective electrocyclization reactions to generate 1-aryl-1H-indenes. Electrocyclization only occurs for allylic cations bearing a 2-substituent, with 2-ester and 2-alkyl substituents both tolerated. In general, the presence of electron-withdrawing substituents deactivates the ring and disfavors cyclization. In contrast, the selectivity of cyclization of systems containing electron-donating substituents depends on the nature and position of the electron-donating group. Electron-donating substituents at the meta position particularly favor cyclization. There was no obvious correlation of cyclization selectivity with calculated electron densities as has been suggested for electrophilic aromatic substitution reactions. However, the calculated selectivities determined by a gas-phase (B3LYP/6-31G* + ZPVE) comparison of the relative rates of cyclization were in remarkably good agreement with the observed selectivities. Calculated transition-state structures for cyclization are consistent with a cationic π4a conrotatory electrocyclization mechanism. In some cases involving more electron-deficient systems, the initially formed 1H-indene underwent subsequent alkene isomerization to the 3H-indene. In one example, an unusual dimerization reaction occurred to give a cyclopenta[a]indene via an unusual formal cationic 2π+2π cycloaddition of the allylic cation with the intermediate indene.
Asymmetric total synthesis of (-)-plicatic acid via a highly enantioselective and diastereoselective nucleophilic epoxidation of acyclic trisubstitued olefins
Sun, Bing-Feng,Hong, Ran,Kang, Yan-Biao,Deng, Li
supporting information; experimental part, p. 10384 - 10385 (2009/12/23)
(Chemical Equation Presented) The first total synthesis of (-)-plicatic acid has been achieved by a concise and enantioselective route. In this synthesis, a conceptually new strategy featuring an asymmetric epoxidation-intramolecular epoxy-ring-opening Friedel-Crafts reaction sequence was developed for the stereoselective construction of the 2,7′- cyclolignane skeleton bearing contiguous quaternary-quaternary-tertiary stereocenters. The implementation of this strategy was enabled by the development of a modified protocol for the Seebach epoxidation with TADOOH, which affords an unprecedented, highly enantioselective and diastereoselective epoxidation with a range of α-carbonyl-β-substituted acrylates 3.
Synthesis of Ethyl 2-Aminodihydro-5-pyrimidinecarboxylate Derivatives and 3,7-Diethoxycarbonyl-4,6-dihydro-2,4,6,8-tetraaryl-lH-pyrimido[1,2-a]pyrimidines
Milcent, Rene,Malanda, Jean-Claude,Barbier, Geo,Vaissermann, Jacqueline
, p. 329 - 336 (2007/10/03)
Reactions of ethyl 3-aryl-2-benZoylpropenoateS 1 with guanidine and N-alkyl(or benzyl)guanidines have been investigated. Ethyl 2-aminodihydro-5-pyrimidinecarboxylate derivatives 3, 4 or 5 and 3,7-diethoxycarbonyl-4,6-dihydro-2,4,6,8-tetraaryl-lH-pyrimido[
RING-OPENING OF 4-ISOXAZOLINES: COMPETITIVE FORMATION OF ENAMINO DERIVATIVES AND α,β-ENONES
Chiacchio, Ugo,Casuscelli, Franco,Liguori, Angelo,Rescifina, Antonio,Romeo, Giovanni,et al.
, p. 585 - 600 (2007/10/02)
Ring-opening of 3-substituted 4-isoxazolines, proceeding through the intermediate isoxazolinium salts, follows two competing reaction pathways leading to α,β-enones and enamines respectively.The rearrangement courses can be controlled as a function of substitution pattern and experimental conditions.
ADDITION OF SODIUM BISULFITE TO DERIVATIVES OF ETHYL ESTERS OF α-SUBSTITUTED CINNAMIC ACIDS
Samarenko, V. Ya.,Markova, N. R.,Passet, B. V.
, p. 122 - 127 (2007/10/02)
The reaction of derivatives of ethyl esters of α-substituted cinnamic acids with sodium bisulfite under conditions excluding radical addition gave the corresponding derivatives of 2-R-substituted sodium 1-phenyl-2-ethoxycarbonyl-1-ethanesulfonates.The eff