17228-90-9Relevant academic research and scientific papers
Bis(2,5-dimethoxy-4-methylphenyl)methane and bis(2,5-dimethoxy-3,4,6-trimethylphenyl)methane.
Wiedenfeld, David J,Nesterov, Vladimir N,Minton, Mark A,Glass, David R
, p. o700-702 (2003)
Bis(2,5-dimethoxy-4-methylphenyl)methane, C(19)H(24)O(4), (IIa), was obtained and characterized as a minor product from the reaction of toluhydroquinone dimethyl ether (1,4-dimethoxy-2-methylbenzene) with N-(hydroxymethyl)trifluoroacetamide. Similarly, bis(2,5-dimethoxy-3,4,6-trimethylphenyl)methane, C(23)H(32)O(4), (IIb), was prepared from the corresponding reaction of trimethylhydroquinone dimethyl ether (2,5-dimethoxy-1,3,4-trimethylbenzene). The molecules of (IIa) and (IIb) each lie on a twofold axis passing through the methylene group. The dihedral angle between the planar phenyl rings is 73.4 (1) degrees in (IIa) and 77.9 (1) degrees in (IIb). The external bond angles around the bridging methylene group are 116.6 (2) and 117.3 (2) degrees for (IIa) and (IIb), respectively. In (IIa), the methoxy substituents lie in the plane of the ring and are conjugated with the aromatic system, whereas in (IIb), they are almost perpendicular to the phenyl ring and are positioned on opposite sides.
A general synthesis of quinone ammonium salts
Wiedenfeld, David,Minton, Mark A.,Glass, David R.,Nesterov, Vladimir N.,Nsamenang, Kila D.,Han, Dong
, p. 1611 - 1618 (2007/10/03)
A three-step procedure has been developed to convert substituted p-dimethoxybenzenes to quinone ammonium salts. Five examples of quinone ammonium salts have been prepared with this procedure. In the first step, the aromatic species is reacted with N-(hydr
Acid catalysis vs. electron-transfer catalysis via organic cations or cation-radicals as the reactive intermediate. Are these distinctive mechanisms?
Rathore, Rajendra,Kochi, Jay K.
, p. 114 - 130 (2007/10/03)
Proton transfer to aromatic and olefinic donors (D) leads to the facile interchange of transient carbocations (DH+) and cation-radical (D+.). The same types of cation and cation-radical are reactive intermediates in the acid catalysis and the electron-transfer catalysis of such organic transformations as benzylic coupling, epoxide/pinacol rearrangements and cis-trans isomerization of stilbenes when they are both carried out under otherwise identical reaction conditions. However, the rapid exchange of diamagnetic cations and paramagnetic cation-radicals blurs the traditional view of separate electrophilic and homolytic processes, and rigorous experimental evidence is required to establish whether acid catalysis and electron-transfer catalysis actually represent distinct mechanistic categories. Acta Chemica Scandinavica 1998.
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.
