13041-62-8Relevant academic research and scientific papers
Behavior of naphthoyloxyl and methoxynaphthoyloxyl radicals generated from the photocleavage of dinaphthoyl peroxides and 1-(naphthoyloxy)-2-pyridones
Najiwara, Toshihiro,Hashimoto, Ji-ichiro,Segawa, Katsunori,Sakuragi, Hirochika
, p. 575 - 585 (2007/10/03)
1-Naphthoyloxyl and 2-naphthoyloxyl radicals were generated from photocleavage of dinaphthoyl peroxides and 1-(naphthoyloxy)-2-pyridones in acetonitrile. The difference in product distribution between the precursors is ascribed to the contribution of the two-bond cleavage in the peroxide decomposition in the singlet state. A series of methoxynaphthoyloxyl radicals were also generated from the corresponding (methoxynaphthoyloxy)pyridones and their behavior was compared with that of unsubstituted naphthoyloxyl radicals. The introduction of a methoxy group in the naphthalene ring stabilizes the naphthoyloxyl radicals to prevent their decarboxylation completely and reduces remarkably their reactivities in the addition to olefins and hydrogen-atom abstraction. The structure of the naphthoyloxyl radicals was discussed on the basis of their absorption spectra and MO calculations.
Thermal and photochemical decomposition pathways of trinitromethylarenes. Part I. The conversion of ArC(NO2)3 to ArNO2 - A rationalization of apparent solvent effects
Eberson, Lennart,Hartshorn, Michael P.,Radner,Svensson, Jan Olof
, p. 885 - 898 (2007/10/03)
The thermal and photochemical decomposition of trinitromethylarenes in an inert solvent (dichloromethane or acetonitrile) has been investigated, using 1-methoxy-4-trinitromethylnaphthalene (2) and 2-trinitromethyl-4-chloroanisole (6) as representatives of reactive and unreactive ArC(NO2)3, respectively. Compound 2 underwent slow thermal decomposition in both solvents to give 4-methoxy-1-naphthoic acid (3) and 1-methoxy-4-nitronaphthalene (5). The reaction was speeded up by additives, such as 1-methoxynaphthalene or nitrous acid. The decomposition of 2 was strongly accelerated by irradiation with light of λ>430 nm. Both the thermal and photochemical processes were faster in acetonitrile than in dichloromethane. Spin trapping experiments resulted in the trapping of ArCOO· radicals, in both the thermal and photochemical reactions, indicating that the decomposition reaction is at least partially of radical nature. The acid 3 was shown to undergo fast thermal nitrodecarboxylation by treatment with NO2 in dichloromethane. Compound 6 exhibited similar behaviour, except that the rates were much slower, less than 100 times slower than those of 2. The mechanism suggested involves an initial nitro→nitrito rearrangement of ArC(NO2)3, followed by homolytic decomposition of the nitritodinitromethylarene formed. The finding that trinitromethylarenes have differing stabilities, depending on the nature of the ring substituent (s) and/or the solvents used, offers a reasonable explanation for the chemoselectivity of tetranitromethane-ArH photolyses. Acta Chemica Scandinavica 1996.
Photochemical Nitration by Tetranitromethane. Part XXII. Adducts as Precursors of Nitro Substitution Products from the Photolysis of 1-Methoxynaphthalene-Tetranitromethane, Dehydrodimer Formation and the Regiochemistry of Trinitromethanide Ion Attack on the Radical Cation of ...
Butts, Craig P.,Eberson, Lennart,Hartshorn, Michael P.,Persson, Ola,Robinson, Ward T.
, p. 253 - 264 (2007/10/02)
The photolysis of 1-methoxynaphthalene with tetranitromethane in dichloromethane at 20 deg C gives mainly 1-methoxy-4-nitronaphthalene (2) and 1-methoxy-4-trinitromethylnaphthalene (5), together with smaller amounts of 1-methoxy-2-nitronaphthalene (1) and the two adducts, 4-methoxy-r-1-nitro-t-2-trinitromethyl-1,2-dihydronaphthalene (6) and 4-methoxy-r-2-nitro-t-1-trinitromethyl-1,2-dihydronaphthalene (7).Photolysis in the presence of trifluoroacetic acid under otherwise identical conditions gives initially exclusively 4,4'-dimethoxy-1,1'-binaphthalene (10) as the product, trinitromethanide ion being eliminated as a reactant by protonation to give nitroform.EPR spectral and cyclic voltammetric data indicate that the radical cation 10 is present in this reaction.Evidence is presented that, in the absence of trifluoroacetic acid, the reaction products 1, 2 and 5 all arise by decomposition of highly labile nitro-trinitromethyl or nitrito-trinitromethyl adducts 11, 12 and 14.The regiochemistry of attack of trinitromethanide ion on the radical cation of 1-methoxynaphthalene is discussed, and it is proposed that this step is reversible, the regiochemistry of attack being determined by the relative energies of the carbon radicals formed in the process.X-Ray crystal structures are reported for 1-methoxy-4-trinitromethylnaphthalene (5) and 4,4'-dimethoxy-1,1'-binaphthalene (10).
Light-initiated and thermal nitration reactions during photolysis of naphthalene/tetranitromethane or 1-methoxynaphthalene/tetranitromethane in dichloromethane
Eberson, Lennart,Radner, Finn
, p. 5825 - 5834 (2007/10/02)
The photolysis of naphthalene or 1-methoxynaphthalene together with tetranitromethane in dichloromethane, using light with a cutoff at λ 2-promoted nitration (α/β ratio ca. 20). The adducts are formed by photochemical excitation of the CT complex between naphthalene and tetranitromethane, resulting in formation of the triad [ArH?+ NO2 (NO2)3C-] from which the observed chemistry develops by attack of trinitromethanide upon the radical cation. For 1-methoxynaphthalene, a representative of more highly reactive aromatics, the reaction is again photochemically initiated and again adducts seem to be responsible for the further development of thermal nitration reactions, apart from the NO2-induced reaction. Elimination of HNO2 from one of the 1,4-adducts induces a novel HNO2/tetranitromethane-dependent nitration process, shown separately to operate in the dark on reactive substrates. The aryltrinitromethane formed in this step is "hydrolyzed" to the corresponding carboxylic acid, 4-methoxy-1-naphthoic acid, under the anhydrous conditions prevailing during photolysis. Nitrous acid is a likely candidate as the proton source for this reaction. With an alcohol present, moderate yields (up to ≈50%) of alkyl 4-methoxy-1-naphthoates are obtained. From other adducts, nitro compounds are formed by elimination of nitroform. Trinitromethanide ion was shown to possess greatly differing reactivity (ratio >103) toward a model radical cation, tris(4-bromophenyl)aminium ion, in dichloromethane and acetonitrile, respectively.
Manganese(III)-Mediated Formylation of Aromatic Compounds in the Presence of Malonic Acid
Nishino, Hiroshi,Tsunoda, Katsunori,Kurosawa, Kazu
, p. 545 - 550 (2007/10/02)
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.
