Heck Reactions in 2,6-Diaryl-3,5-dibromo-4-pyrones in the Presence of N,N’-Dibutylbenzimidazolium Bromide
摘要:
Synthesis of two 2,6-diaryl-3,5-dibromo-4-pyrone derivatives is described, by using of NBS/DMF bromination of related 2,6-diaryl-4-pyrones. PdCl(2) catalyzed Heck coupling reactions of these dibromides, with emphasis on the use of N,N'-dibutylbenzimidazol-2-ylidene as ligand, resulted in the formation of two class of mono- and di-vinylated products.
Heck Reactions in 2,6-Diaryl-3,5-dibromo-4-pyrones in the Presence of N,N’-Dibutylbenzimidazolium Bromide
摘要:
Synthesis of two 2,6-diaryl-3,5-dibromo-4-pyrone derivatives is described, by using of NBS/DMF bromination of related 2,6-diaryl-4-pyrones. PdCl(2) catalyzed Heck coupling reactions of these dibromides, with emphasis on the use of N,N'-dibutylbenzimidazol-2-ylidene as ligand, resulted in the formation of two class of mono- and di-vinylated products.
AbstractPalladium-catalyzed cross-coupling reactions of 2,6-diaryl-3,5-dibromo-4-pyrones with imidazole and benzimidazole in the presence of N,N′-dibutylbenzimidazol-2-ylidene as ligand resulted in the formation of the monosubstituted C- and N-arylated products. Kojicacid was also treated with some aryl halides at the same conditions, to afford C-6 arylated derivatives. Graphical abstract