84602-61-9Relevant academic research and scientific papers
Kinetic and thermodynamic analysis of induced-fit molecular recognition between tetraarylporphyrin and ubiquinone analogues
Hayashi, Takashi,Asai, Tomohito,Borgmeier, Frieder M.,Hokazono, Hirohisa,Ogoshi, Hisanohu
, p. 1266 - 1274 (1998)
meso-Tetrakis(2-hydroxy-4 nonylphenyl)porphyrin (1), which was prepared as a host molecule for ubiquinone analogues, comprises four atropisomers, αααα, αααβ, ααββ, and αβαβ, in a statistical ratio of 1:4:2:1, respectively. The atropisomerization is due to
A 'meta effect' in the fragmentation reactions of ionised alkyl phenols and alkyl anisoles
Bouchoux, Guy,Sablier, Michel,Miyakoshi, Tetsuo,Honda, Takashi
scheme or table, p. 539 - 546 (2012/09/22)
The competition between benzylic cleavage (simple bond fission [SBF]) and retro-ene rearrangement (RER) from ionised ortho, meta and para RC 6H4OH and RC6H4OCH3 (R = n-C3H7, n-C4H9, n-C5H11, n-C7H15, n-C9H19, n-C 15H31) is examined. It is observed that the SBF/RER ratio is significantly influenced by the position of the substituent on the aromatic ring. As a rule, phenols and anisoles substituted by an alkyl group in meta position lead to more abundant methylene-2,4-cyclohexadiene cations (RER fragmentation) than their ortho and para homologues. This 'meta effect' is explained on the basis of energetic and kinetic of the two reaction channels. Quantum chemistry computations have been used to provide estimate of the thermochemistry associated with these two fragmentation routes. G3B3 calculation shows that a hydroxy or a methoxy group in the meta position destabilises the SBF and stabilises the RER product ions. Modelling of the SBF/RER intensities ratio has been performed assuming two single reaction rates for both fragmentation processes and computing them within the statistical RRKM formalism in the case of ortho, meta and para butyl phenols. It is clearly demonstrated that, combining thermochemistry and kinetics, the inequality (SBF/RER) metaorthopara holds for the butyl phenols series. It is expected that the 'meta effect' described in this study enables unequivocal identification of meta isomers from ortho and para isomers not only of alkyl phenols and alkyl anisoles but also in other alkyl benzene series. Copyright
Synthesis of novel structurally simplified estrogen analogues with electron-donating groups in ring A
Tietze, Lutz F.,Vock, Carsten A.,Krimmelbein, Ilga K.,Nacke, Linda
experimental part, p. 2040 - 2060 (2009/12/27)
A library of 25 novel estrogen analogues were prepared in five to eight steps from mostly commercially available substituted anisoles via bromination, formylation, Corey-Fuchs reaction, elimination, and Sonogashira reaction. Georg Thieme Verlag Stuttgart.
