Mild Palladium-Catalyzed Regioselective Direct Arylation of Azoles Promoted by Tetrabutylammonium Acetate
作者:Fabio Bellina、Marco Lessi、Chiara Manzini
DOI:10.1002/ejoc.201300704
日期:2013.9
A mild, general, and convenient palladium-catalyzeddirectarylation of the 5-position of azoles with aryl bromides, efficiently promoted by tetrabutylammonium acetate, is described. 1-Methylpyrazole, oxazole, and thiazole reacted at 70 °C in N,N-dimethylacetamide by using Pd(OAc)2 as the catalyst precursor. Electron-poor and -rich functional groups, including the free hydroxy group, are well tolerated
Programmed synthesis of arylthiazoles through sequential C–H couplings
作者:Satoshi Tani、Takahiro N. Uehara、Junichiro Yamaguchi、Kenichiro Itami
DOI:10.1039/c3sc52199k
日期:——
A programmed synthesis of privileged arylthiazoles via sequential C–Hcouplings catalyzed by palladium or nickel catalysts has been accomplished. This versatile protocol can supply all possible arylthiazole substitution patterns (2-aryl, 4-aryl, 5-aryl, 2,4-diaryl, 2,5-diaryl, 4,5-diaryl, and 2,4,5-triaryl) from an unfunctionalized thiazole platform by 11 distinct synthetic routes. We have generated
In contrast, the use of aromatic solvents as the reaction medium for directarylations, although some of them show good EHS values, is poorly reported, probably due to their low solvent power against reagents and their potential involvement in undesired side reactions. In this paper we report an unprecedented selective C-5 arylation procedure involving anisole as an EHS green reaction solvent. In addition