Detailed studies have been conducted to determine the activity of palladium catalysts for the\namination of five-membered heterocyclic halides and to determine the factors that control the scope\nof this reaction. Palladium-catalyzed aminations of the electron-rich furanyl, thiophenyl, and indolyl\nhalides and of the related 2-halogenated thiazoles, benzimidazole, and benzoxazole have been shown\nto occur with a subset of amines. Various combinations of palladium precursors and P<i><sup>t</sup></i><sup></sup>Bu<sub>3</sub> were\ntested as catalysts for reaction of 3-bromothiophene with <i>N</i>-methylaniline, and the fastest reactions\noccurred with the Pd(I) dimer, [PdBr(P<i><sup>t</sup></i><sup></sup>Bu<sub>3</sub>)]<sub>2</sub>. The fastest aminations of thiazoles, benzimidazoles,\nand benzoxazoles occurred with the combination of palladium trifluoroacetate and P<i><sup>t</sup></i><sup></sup>Bu<sub>3</sub> as catalyst.
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