Free-radical reactions of a [3.1.1]propellane, 2, 4-methano-2, 4-didehydroadamantane (CROSBI ID 268339)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Mlinarić-Majerski, Kata ; Majerski, Zdenko ; Rakvin, Boris ; Veksli, Zorica
engleski
Free-radical reactions of a [3.1.1]propellane, 2, 4-methano-2, 4-didehydroadamantane
2, 4-Methano-2, 4-didehydroadamantane (1), a prototype small propellane, readily added disulfides and carbon tetrachloride across the central bond to give the corresponding 2, 4-disubstituted 2, 4-methanoadamantanes. Methyl phenyl disulfide as well as mixtures of dimethyl disulfide and diphenyl disulfide produced 2-(methylthio)-4-(phenylthio)-2, 4-methanoadamantane (4) in addition to the symmetrical disulfides, 2, 4-bis(methylthio)-2, 4-methanoadamantane (2) and 2, 4-bis(phenylthio)-2, 4-methanoadamantane (3). The simultaneous formation of 2, 3, and 4 provides strong evidence that these reactions are indeed free-radical chain processes. Carbon tetrachloride, when present in an excess over 1, generated a strong ESR signal corresponding to the 4-substituted 2, 4-methano-2-adamantyl radical (5). The structure of this radical was confirmed by ESR of the radical derived from 2, 4-methano-2, 4-didehydroadamantane-11, 11-d2 (1a). The ESR signal appeared only when carbon tetrachloride was present in an excess over 1, which indicated that 1 was a very efficient free-radical trap. Propellane 1 spontaneously reacted with α-phenyl-N-tert-butylnitrone, a spin-trapping agent, and p-benzoquinone, an electron-deficient olefin. The former reaction led to the corresponding nitroxide radical, and the latter one gave 4-methyleneadamantane-2-spiro-7′-bicyclo[4.1.0]hept-3′-ene-2′, 5′-dione (9), most probably via a diradical intermediate. The behavior of 1 in all these reactions is consistent with the partial diradical character of this small propellane and suggests the term "diradicaloid" for such species.
propellane ; diradicaloid ; free-radical reactions
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
Podaci o izdanju
54 (3)
1989.
545-548
objavljeno
0022-3263
1520-6904
10.1021/jo00264a008