49602-91-7Relevant articles and documents
Manganese(III) acetate-mediated oxidative coupling of phenylhydrazines with benzene: A novel method for biaryl coupling
Demir,Reis,Oezguel-Karaaslan
, p. 3042 - 3045 (2007/10/03)
The reaction of phenylhydrazines with benzene in the presence of manganese(III) acetate affords biaryls in good yields. The same reaction was carried out with similar oxidants, such as CoIII, CeIV and PbIV; among these oxidants MnIII acetate shows higher efficiency and selectivity.
PALLADIUM(II)-CATALYZED OXIDATIVE COUPLING OF ARENES BY THALLIUM(III)
Yatsimirsky, Anatoly K.,Deiko, Sergei A.,Ryabov, Alexander D.
, p. 2381 - 2392 (2007/10/02)
Oxidation of benzenes with electron-donating and moderate electron-withdrawing substituents by thallium(III) trifluoroacetate in the presence of catalytic amounts of palladium(II) acetate affords biaryls in good yields.The GLC study of the isomer distribution has shown that 4,4'-biaryls are the major products.Thus, the 4,4'-biaryls can be easily isolated either by recrystallization or column chromatography.The competitive experiments and kinetic study using arenes and arylthallium derivatives as starting materials as well as quenching experiments have demonstrated the first step of the reaction to be fast thallation of arene to form arylthallium intermediate ArTl(OOCCF3)2.The latter undergoes the rate-determining transmetallation step reacting with monomeric complex Pd(OAc)2, which is formed upon depolymerization of trimer Pd3(OAc)6.Subsequent fast decomposition of arylpalladium species gives the final reaction products.The thallation of arene and substitution of TlIII for PdII in ArTl(OOCCF3)2 are characterized by the slopes of Hammet plots of -5.6 (?+) and -3.0 (?), respectively.
Aryl radicals from hexazadienes and tetrazenes
Mackay, Donald,McIntyre, Deane Douglas
, p. 990 - 999 (2007/10/02)
Aryl radicals are produced from both ends of the hexazadienes 1 and 2 and from the tetrazene 3, either thermally or photolytically.They attack aromatic compounds in the nucleus, the yield of biaryl being in the range 40-70percent, though it can be made nearly quantitative by using m-dinitrobenzene as additive.The aryl radicals also oxidize 2-propanol to acetone, the reaction products being the halogenobenzene and 1,2-diacetylhydrazine.Photolysis of 1 goes mainly by way of the tetrazene 3, and this may also be a significant pathway in the thermal reaction.Azodiacetylis an intermediate in the thermal reaction of 1 with 2-propanol and may be generally so in all its reactions.Radical induced decomposition is believed to be important in the reactions of 1, 2, and 3, and it is probably responsible for the formation of 1-acetyl-1-arylhydrazines, routinely produced in yields up to 25percent.