4281-17-8Relevant academic research and scientific papers
Intramolecular Hydrogen-Atom Transfer in 2-Alkylbenzoyloxyl Radicals as Studied by Transient Absorption Kinetics and Product Analyses on Photodecomposition of Bis(2-alkylbenzoyl) Peroxides
Wang, Jun,Tsuchiya, Masahiro,Tokumaru, Katsumi,Sakuragi, Hirochika
, p. 1213 - 1219 (2007/10/02)
The pulsed-laser excitation of bis(2-methylbenzoyl) peroxide at 308 nm in acetonitrile afforded a broad absorption band at 500-800 nm due to 2-methylbenzoyloxyl radicals.The decay of this band accompanied the growth of another band at 350 nm due to 2-carboxybenzyl radicals produced by an intramolecular hydrogen-atom transfer from the neighboring 2-methyl group; the rate constant was 1.7*107 s-1 at 23 deg C, the activation energy and frequency factor being 17 kJ mol-1 and 1010.5 s-1, respectively.The rates for intramolecular hydrogen-atom transfer in2-MeCH2C6H4CO2. and 2-PhCH2C6H4CO2. are much higher than that in 2-CH3C6H4CO2., since the parent peroxides, (2-MeCH2C6H4CO2)2 and (2-PhCH2C6H4CO2)2, exhibited only 350-nm bands ascribable to the corresponding 2-carboxybenzyl radicals, even immediately after laser excitation.The pulsed-laser photolyses of the above-mentioned peroxides afforded PhCH2R, 2-HOCOC6H4CH(R)CH2CN, and 2-HOCOC6H4CHRCHRC6H4CO2H-2 (R=H, Me and Ph) as the main products in acetonitrile.The formation of PhCH2R is explained in terms of the contribution of two-bond fission of the O-O and C(α)-C bonds of the peroxide in the excited singlet state in competition with O-O bond cleavage followed by an intramolecular hydrogen-atom transfer.
Studies in the Cycloproparene Series: Reactions with Radicals
Chai, Christina L. L.,Christen, Detlev,Halton, Brian,Neidlein, Richard,Starr, Malcolm A. E.
, p. 577 - 592 (2007/10/02)
The behaviour of 1H-cyclopropabenzene (1) and 1H-cyclopropanaphthalene (23) towards a variety of radicals results in opening of the three-membered ring to give ortho-substituted benzyl and 2-methylnaphthalene derivatives, e.g. (13) and (28), respectively.Ring expansion into the cycloheptatriene manifold by way of addition to the bridge bond and norcaradiene formation have not been observed.Analogous reactions with the methylidenecyclopropanaphthalenes (33) and (34) lead to much decomposition, and provide little evidence for the C 1 cycloproparenyl radicals (35) and (36).
195. Conventional and Laser Photolysis of a Bisdiazo Compound
Hannemann, Klaus,Wirz, Jakob,Riesen, Andreas
, p. 1841 - 1857 (2007/10/02)
Entirely different product distributions were observed when the bisdiazo compound 1 was irradiated by a conventional lamp (254 nm) on the one hand and by a pulsed excimer laser (248 nm) on the other.Continuous photolysis gave a complex reaction mixture (S
A ONE POT REACTION INVOLVING HYDROLYSIS-REDUCTION OF BIPHTHALYLIDENE IN AN ALKALINE MEDIUM
Tashiro, Masashi,Sumida, Tsuyoshi,Fukata, Gouki
, p. 657 - 660 (2007/10/02)
The hydrolysis of biphthalylidene (2) in varying alkaline medium afforded selectively 2,2'-dicarboxybenzoin (3) or 5,5'-dihydro-5-oxo-diphthalylidene (4) in good yields depending upon the conditions used.In one pot reaction involving hydrolysis of 2 followed by reduction with Raney-alloys, 4b,10b-dihydrobenzopyranobenzopyrano-6,12-dione (9) was almost selectively obtained in good yields.In the case of the combination of hydrolysis in 10percent KOH aq and Al-Ni alloy reduction, 2,2'-dicarboxybibenzyl (8) yielded in 51percent as a sole product.
