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DOI: 10.1055/s-2007-968264
Cross-Coupling Reactions of DiazineN-Oxides with Aryl Halides
J.-P. Leclerc, K. Fagnou*
University of Ottawa, Canada
Publikationsverlauf
Publikationsdatum:
20. Februar 2007 (online)
Significance
A reasonably efficient Pd-catalyzed cross-coupling of diazine N-oxides with arylhalides to afford aryl diazines is reported. In view of the absence of metalated (B, Zn, Mg, Sn) partners, the process may be formally categorized in the C-H-activation group of reactions. The reaction proceeds with pyrazines, pyrimidines, and pyridazine N-oxides to introduce aryl substituents ortho to the N-oxide function. The scope of heterocycle substitutent R1 received inadequate attention whereas that of R2, the aryl halides (bromides, iodides, and even chlorides), has been thoroughly investigated in terms of electron-donating and -withdrawing groups. An interesting catalyst inhibitory effect in the coupling reactions of pyrimidine N-oxides was noted but not elucidated.