571-58-4Relevant academic research and scientific papers
Competition between Birch Reduction and Bond Cleavage in 1,2-Bis(4-methyl-1-naphthyl)ethane
Marcinow, Zbigniew,Hull, C. Eugene,Rabideau, Peter W.
, p. 3602 - 3605 (1989)
The reaction of 1,2-bis(4-methyl-1-naphthyl)ethane with Li, Na, and K in ammonia, THF, and HMPA, or mixtures thereof, has been examined with respect to the factors favoring Birch reduction of the aromatic ring and cleavage of the ethane carbon-carbon bond.Bond cleavage was found to increase relative to ring reduction in the series Li Na K and with the solvents NH3 THF HMPA.However, the latter position of ammonia may be due to the necessarily restricted low-reaction temperature since only ring reduction was observed at temperatures at or below the boiling pointof ammonia (-33 deg C).A number of reduction and cleavage products were isolated and identified, and the mechanistic pathways for their formation is discussed.
"off-on" switching of intracellular singlet oxygen release under biocompatible conditions
Ucar, Esma,Xi, Dongmei,Seven, Ozlem,Kaya, Cansu,Peng, Xiaojun,Sun, Wen,Akkaya, Engin U.
, p. 13808 - 13811 (2019)
Precise spatiotemporal control of singlet oxygen generation is of immense importance considering its involvement in photodynamic therapy. In this work, we present a rational design for an endoperoxide which is highly stable at ambient temperatures yet, can rapidly be converted into a highly labile endoperoxide, thus releasing the "stored" singlet oxygen on demand. The "off-on" chemical switching from the stable to the labile form is accomplished by the reaction with fluoride ions. The potential utility of controlled singlet oxygen release was demonstrated in cell cultures.
Chemiluminescence during decomposition of 1,4-dimethylnaphthalene endoperoxide on the silica gel and alumina surface
Kazakov,Mal'tsev,Maistrenko,Khursan,Ovchinnikov,Kazakov
, p. 205 - 210 (2007)
Decomposition of 1,4-dimethylnaphthalene endoperoxide supported on the silica gel and alumina surface is accompanied by chemiluminescence (CL) in the IR and visible spectral regions. The CL emitter in the IR region is singlet oxygen. The 1O2 dimol contributes mainly to the emission at λmax = 630 and 700 nm. It was shown by the IR-CL method that endoperoxide decomposition on the sorbent surface follows the first-order kinetics. The activation parameters of the process were determined. On the Al2O3 and silica gel surfaces a substantial acceleration of the decomposition of 1,4-dimethylnaphthalene endoperoxide is observed compared to the solution.
Tetrahydronaphthalene-1,4-dione and its chromiumtricarbonyl complex
Garcia, Alvaro Enriquez,Kuendig, E. Peter,Lomberget, Thierry,Bragg, Ryan,Poulard, Cyril,Bernardinelli, Gerald
, p. 169 - 171 (2007)
The article gives a brief outline of the rediscovery of tetrahydronaphthalene-1,4-dione, a stable tautomer which has been known for over half a century but has not been applied in synthesis. Desymmetrization is readily achieved via enantioselective reduction. Synthetic potential apart, the dione and its chromiumthcarbonyl complex are of theoretical interest. Thus, whereas dihydroxynaphthalene requires quite harsh conditions and leads to a 1:1 mixture of the two tautomers, the chromiumtricarbonyl complex of dihydroxynaphthalene tautomerizes under very mild conditions to the tetrahydronaphthalene-1,4-dione complex. An earlier literature report showed that in trifluoroacetic acid, the dione tautomer is present exclusively. This has now been used to isolate multigram quantities of the compound. Schweizerische Chemische Gesellschaft.
Formal total synthesis of (±)-occidol
Vera, William J.,Banerjee, Ajoy K.
, p. 3091 - 3094 (2006)
The conversion of tetralone 1 to methylketone 7, a valuable intermediate of occidol 8, has been accomplished in four steps (reduction, mesylation, cyanation, and Grignard reaction with methylmagnesium bromide). Copyright Taylor & Francis Group, LLC.
Laser flash-chemiluminescence study of O2(1Δ) photoeliminated from 1,4- dimethylnaphthalene endoperoxide
Chou, Pi-Tai,Frei, Heinz
, p. 3843 - 3854 (1987)
Deactivation of O2(1Δ) photoeliminated from electronically excited 1,4-dimethylnaphthalene endoperoxide in acetonitrile and perdeuteroacetonitrile has been monitored by time resolved detection of O21Δg -> 3Σg- chemiluminescence at 1.27 μ.Study of the chemiluminescence decay as a function of laser photolysis pulse energy and endoperoxide concentration was undertaken in order to elucidate the processes that cause the previously reported drastic lifetime shortening of O2(1Δ) photoeliminated from this singlet oxygen storing molecule.Analysis of the non-first-order decay revealed that, aside from solvent collisional deactivation, quenching of O2(1Δ) by O2- plays a dominant role at higher photolysis laser pulse energy or endoperoxide concentration.Kinetic evidence suggests that superoxide is generated upon 266 nm endoperoxide photolysis mainly along a two photon excitation path.The ionic fragmentation channel has been confirmed by direct observation of dimethylnaphthalene cation radicals in transient absorption in the red spectral range.In order to find out about the possible role of O2(1Δ) self annihilation through pooling of the energy in O2(1S+), the rate constant of this process has been determined in a separate series of photosensitization experiments as (2.6+/-0.8) X 107 lmol-1s-1 (C6F6).This value implies that marked contribution of O2(1Δ) pooling to nonexponential singlet O2 decay occurs only at high laser photolysis pulse energies or endoperoxide concentrations.
Nonradiative deactivation of singlet oxygen (1O2) by cubane and its derivatives
Lancaster, Jeffrey R.,Marti, Angel A.,Lopez-Gejo, Juan,Jockusch, Steffen,O'Connor, Naphtali,Turro, Nicholas J.
, p. 5509 - 5512 (2008)
(Chemical Equation Presented) The bimolecular quenching rate constants of singlet oxygen (1O2) by cubane and cubane derivatives were determined and found to be in the order of 103-104 M -1 s-1. These values represent larger values than expected for aliphatic alkanes as a model for C-H vibrational deactivation. This result is explained by the occurrence of two different deactivation mechanisms: energy transfer to cubane C-H vibrational modes and the formation of a charge-transfer complex between 1O2 and cubane (1O 2?- ...cubane?+).
141. The Vitamin-B12-derived Co(III)-Complex 'Pyrocobester' as Photosensitizer and as Substrate in Reactions Involving 'Singlet Oxygen'
Kraeutler, Bernhard,Stepanek, Rene
, p. 1493 - 1512 (1983)
The vitamin-B12 derivative 'pyrocobester'(1) acts as photosensitizer in its light-induced oxygenation which involves 'singlet oxygen' (1O2) and which gives '5,6-dioxosecopyrocobester' (2) cleanly.The identity of the photosensitizer is deduced from a match of the 'photochemical action spectrum' of the photooxygenation with the UV/VIS absorption spectrum of 1.The involvement of 1O2 in this reaction is established on the basis of solvent and solvent H/D isotope effects, of quenching studies with β-carotene and of competition experiments with 9,10-dimethyl-anthracene.Also, decomposition of the thermal 1O2-source 1,4-dimethylnaphthalene-1,4-endoperoxide in a solution of 1 induces a clean oxygenation of 1 to2 in the dark as well.
The Reactions of O2 (1Δg) with Anancomeric 1,3-Dithianes. The First Experimental Evidence in Support of a Hydroperoxy Sulfonium Ylide as a Precursor to Sulfoxide on the Sulfide Singlet Oxygen Reaction Surface
Toutchkine,Clennan
, p. 5620 - 5625 (1999)
The kinetic isotope effects for the formation of anancomeric 1,3-dithiane-1-oxides in the reactions of singlet oxygen with the parent 1,3-dithianes have been determined for a series of 2-protio and 2-deuterio analogues. The substantial isotope effects are used to argue for formation of a hydroperoxysulfonium ylide as a key intermediate in sulfoxide formation. These results confirm an earlier theoretical prediction and force a change in the currently accepted mechanism for this important reaction. The first experimental demonstration of a novel singlet oxygen-induced epimerization of a 1,3-dithiane and a novel intramolecular electron transfer within a hydroperoxysulfonium ylide are also reported.
Deoxygenation of Arene 1,4-Endoxides with Low-Valent Metals
Hart, Harold,Nwokogu, Godson
, p. 1251 - 1255 (1981)
Low-valent forms of iron, tungsten, and titanium, produced by treatment of the metal chlorides with butyllithium at -78 deg C, are useful deoxygenation catalysts for the conversion of 1,4-endoxides to the corresponding arenes in a single step.In some instances, particulary with highly substituted endoxides, other reactions may interefere.For example, with methyl substituents at C2 and C3 and with reduced iron, reduction of the C2-C3 double bond and a 1,3 hydrogen shift occur.Also, hindered aromatic methoxyls may be replaced by hydrogen.Use of this deoxygenationmethod to prepare 1,4,5,8,9,10-hexamethylanthracene, a compound with multiple peri interactions, is described.
