Palladium catalysts for highly selective Sonogashira reactions of aryl and heteroaryl bromides.
Palladium catalysts have been studied for the Sonogashira-Hagihara coupling of aryl and heteroaryl bromides with terminal alkynes. Among the different biarylphosphines tested, 2-(di-tert-butylphosphino)-N-phenylindole (cataCXium Plntb) allows the efficient coupling of both activated and deactivated (hetero)aryl bromides in the presence of sodium tetrachloropalladate in tetramethylethylenediamine (TMEDA) at 80 degrees C. The catalyst system gives high turnover numbers (up to 14 100) and shows a broad tolerance towards functional groups such as OH and NH2, as well as heterocycles.
Torborg
Christian
C
Leibniz-Institut für Katalyse an der Universität Rostock e.V, Albert-Einstein-Strasse 29A, 18059 Rostock, Germany.
Zapf
Alexander
A
Beller
Matthias
M
D000480:Alkynes / Q000737:chemistry; D002384:Catalysis; D006842:Hydrocarbons, Brominated / Q000737:chemistry*; D008024:Ligands; D010165:Palladium / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013379:Substrate Specificity
D000480:Alkynes; D006842:Hydrocarbons, Brominated; D008024:Ligands; D012997:Solvents; D010165:Palladium