- Controlled photochemical release of nitric oxide from O2-naphthylmethyl- and O2-naphthylallyl-substituted diazeniumdiolates
-
The photochemistry of O2-naphthylmethyl- and O2-naphthylallyl-substituted diazeniumdiolates has been investigated. Electron-donating methoxy group substitution is shown to have a significant effect on the observed photochemistry, with the appropriate substitution pattern resulting in efficient diazeniumdiolate photorelease. Observed nitric oxide release rates from these photoprecursors are consistent with those expected for normal thermal dissociation of the diazeniumdiolate in aqueous solutions and show the same pH dependence. Copyright
- Bushan, K. Mani,Xu, Hua,Ruane, Patrick H.,D'Sa, Raechelle A.,Pavlos, Christopher M.,Smith, Joseph A.,Celius, Tevye C.,Toscano, John P.
-
p. 12640 - 12641
(2007/10/03)
-
- Evidence for the intracomplex reaction in Gattermann-Koch formylation in superacids: Kinetic and regioselectivity studies
-
Kinetic and regioselectivity data are reported for the Gattermann-Koch formylation of m-xylene, l-methylnaphthalene, and toluene in HF-SbF5 and CF3SO3H-SbF5 as a function of SbF5/substrate molar ratio. The kinetic study for m-xylene formylation in HF-SbF5 provided crucial evidence in favor of intracomplex reaction via a third-order rate equation, [ArH][ArH2+SbF6-][CO], where the formylation electrophile HCO+ is generated by CO protonation by the arenium ion. Dependence of regioselectivity on substrate, superacid, and SbF5/substrate molar ratio showed that high para regioselectivity stems from intracomplex reaction and the observed regioselectivity reflects the ratio between the intracomplex and the conventional reactions. Comparison in regioselectivity between Gattermann-Koch formylation and Friedel-Crafts formylation with use of HCOF suggested that regioselectivity trends do not reflect the nature of the electrophile but the reaction pathway; the Friedel-Crafts formylation also appears to have intracomplex reaction character.
- Tanaka, Mutsuo,Fujiwara, Masahiro,Xu, Qiang,Souma, Yoshie,Ando, Hisanori,Laali, Kenneth K.
-
p. 5100 - 5105
(2007/10/03)
-
- The influence of aromatic compound protonation on the regioselectivity of Gattermann-Koch formylation
-
The regioselectivity of the Gattermann-Koch formylation is influenced by the protonation of aromatic compounds under a solvent-cage-like atmosphere.
- Tanaka, Mutsuo,Fujiwara, Masahiro,Ando, Hisanori,Souma, Yoshie
-
p. 159 - 160
(2007/10/03)
-
- Manganese(III)-Mediated Formylation of Aromatic Compounds in the Presence of Malonic Acid
-
The reaction of naphthlenes with malonic acid in the presence of manganese(III) acetate gives naphthalenecarbaldehydes and naphthalenecarboxylic acids.Similar reactions of anthracene, pyrene, and methoxybenzenes also yield formylated and carboxylated products.It was found that the formyl group introduced to the aromatic ring was not derived from carboxymethyl radical generated directly by the thermolysis of manganese(III) acetate, but from a dicarboxymethyl radical formed by the interaction of malonic acid and manganese(III) acetate.In addition, it was also found that the dicarboxymethyl radicals attacked the position of the highest electron density on the aromatic ring and that this formylation was effective when the ionization potential of the aromatic copound was lower than 7.8 eV.
- Nishino, Hiroshi,Tsunoda, Katsunori,Kurosawa, Kazu
-
p. 545 - 550
(2007/10/02)
-
- ELECTRON TRANSFER ACTIVATION. HYDROPEROXIDE INTERMEDIATES IN A NOVEL AND SELECTIVE PROCEDURE FOR BENZYLIC OXIDATIONS.
-
A selective and mild photochemical procedure for benzylic oxidations with 9,10-dicyanoanthracene (DCA) an usual electron acceptor, in the presence of methyl viologen (MV2+), an electron relay, has been developed.Methyl and methylene groups are oxidized in good to excellent yields to the corresponding hydroperoxides.
- Santamaria, J.,Jroundi, R.,Rigaudy, J.
-
p. 4677 - 4680
(2007/10/02)
-
- Exciplex and Radical Ion Intermediates in Electron-transfer Reactions: Solvent effect on the Photo-oxygenation of 1,4-Dimethylnaphthalene sensitized by 9,10-Dicyanoanthracene
-
The 9,10-dicyanoanthracene-sensitized photo-oxygenation of 1,4-dimethylnaphthalene is shown to depend on solvent polarity.Radical ion pair and singlet exciplex are suggested to be intermediates in this photochemical reaction.Mechanisms consistent with the effects of solvent polarity are proposed.
- Bokobza, Liliane,Santamaria, Jean
-
p. 269 - 272
(2007/10/02)
-
- PHOTOOXYGENATIONS PAR TRANSFERT D'ELECTRON SENSIBILISEES PAR LE DICYANO-9,10 ANTHRACENE. ROLE DU SOLVANT ET FORMATION D'OXYGENE SINGULET.
-
Photooxygenation of naphtalenic compounds sensitized by electron acceptors like 9,10 dicyanoanthracene (DCA) is shown to proceed by two distinct ways depending on the solvent polarity.In a polar solvent superoxide ion (O2-.) as well as singlet oxygen (1O2*) are involved while in a non polar solvent only singlet oxygen is produced.
- Santamaria, J.,Gabillet, P.,Bokobza, L.
-
p. 2139 - 2142
(2007/10/02)
-