ZIRCONIUM-CATALYZED OXIDATION OF PRIMARY AROMATIC-AMINES TO NITRO-COMPOUNDS USING TERT-BUTYLHYDROPEROXIDE

A broad range of primary aromatic amines (1a-x) with electron donating and accepting substituents are oxidized in good to excellent yields t o the nitro compounds 3a-x using tert-butylhydroperoxide as the oxidan t and Zr(OtBu)(4) as the catalyst. The corresponding nitroso compounds 2m, 2n, 2s and 2u can be isolated in the conversion of electron-rich anilines 1m, 1n, 1s and 1u. The aminopyridines 5a-d are also converted to the corresponding nitropyridines 6a-d, but in lower yields (41-47% ).