Heteroaromatic oxidation oxazole

Oxazole chemistry, advances in, 17, 99 Oxazolone chemistry new developments in, 21, 175 recent advances in, 4, 75 Oxidation of monocyclic pyrroles, 15, 67 Oxidative transformations of heteroaromatic iminium salts, 41, 275 3-Oxo-2,3-dihydrobenz[d]isothiazole 1,1-dioxide (saccharin) and derivatives, IS, 233... 

Bromide or stoichiometric Silver(I) Oxide, respectively. In many cases, one or both of the aromatic species can be heteroaromatic such as pyridine, furan, thiophene, quinoline, oxazole, thia-zole, or indole. Symmetrical biaryls have been prepared in excellent yields by the Pd(Ph3P)4-catalyzed homocoupling of ArBr/I under phase transfer conditions. ... 

Several oxidative catalytic systems utilizing elemental iodine as the catalyst have been developed. Wang and colleagues have reported several tandem oxidative cyclization reactions using I2 as a catalyst and 70% aqueous TBHP (Bu OOH) as a stoichiometric oxidant (Scheme 4.77) [119-122], Heteroaromatic compounds such as oxazoles 151, quinazolines 152 and pyridine derivatives 153 were synthesized in moderate to high yields under these catalytic conditions. The authors suggested that the h/l catalytic cycle might play an important role in the radical mechanism under these conditions [122]. 

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