144707-05-1Relevant articles and documents
Diels-alder trapping of ortho-quinone methides. A new entry to substituted xanthene- 1,4-diones
Giraud, Luc,Giraud, Anne
, p. 1153 - 1160 (2007/10/03)
Highly regioselective Diels-Alder reactions of a non-protected β-hydroxy quinone have been achieved after formation of chelated lithium alkoxides. In this report, we demonstrate on a model system, that the selectivity of reactions based on 1,3-dioxy-subst
Radical-Cation Catalysis in the Synthesis of Diphenylmethanes via the Dealkylative Coupling of Benzylic Ethers
Rathore, Rajendra,Kochi, Jay K.
, p. 7479 - 7490 (2007/10/03)
The dealkylative coupling of benzyl alkyl ethers (ArCH2OR) to yield the corresponding diarylmethanes (ArCH2Ar) together with dialkoxymethane (ROCH2OR) is catalyzed by small amounts of 1-electron oxidants (such as aromatic cation radicals, NO(1+), etc.) or by an equivalent electrochemical (anodic) method.The catalytic method is successfully employed for the facile synthesis of a novel macrocyclic crown ether 18 that contains a diarylmethane linkage.On the basis of the spectral observation of the radical cation ArCH2OR.+ and the excellent catalytic efficiency with turnover numbers in excess of 1E2, an electron-transfer and an alternative electrophilic chain mechanism are discussed for the dealkylative coupling process.
Selective nitration versus oxidative dealkylation of hydroquinone ethers with nitrogen dioxide
Rathore,Bosch,Kochi
, p. 6727 - 6758 (2007/10/02)
Various alkyl-substituted p-dialkoxybenzenes (ArH) react readily with nitrogen dioxide (NO2) in dichloromethane solution via either nitration (ArNO2) or oxidative dealkylation to quinones (Q). Spectral transients indicate that these coupled processes proceed from the dialkoxybenzene radical cation (ArH+) formed as the common reactive intermediate from electron-transfer in the disproportionated precursor [ArH, NO+]NO3-. In fast subsequent steps, ArH+ undergoes homolytic coupling with NO2 (which leads to aromatic nitration) and nucleophilic attack of NO3- (which results in oxidative dealkylation). As such, the competition between nitration and oxidative dealkylation is effectively modulated by solvent polarity and added nitrate.
SYNTHESIS OF DIQUINONE DERIVATIVES OF DEUTEROPORPHYRIN IX FOR THE STUDY OF THE FIRST STAGE IN THE PROCESS OF PHOTOSYNTHESIS
Borovkov, V. V.,Evstigneeva, R. P.,Makova, S. Z.
, p. 142 - 147 (2007/10/02)
Diquinone derivatives of deuteroporphyrin IX containing covalent bridges of different lengths between the chromophores have been synthesized.The compounds were prepared by the condensation of hydroxy-quinones with deuteroporphyrin IX using a mixed anhydri
