Spin Trapping of Radical Intermediates Generated by the Oxidation of Substituted 4-Methylphenols

✍ Scribed by Petr Majzlík; Ladislav Omelka; Renata Superatová; Petra Holubcová

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: German
• Weight: 253 KB
• Volume: 94
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.201000431

✦ Synopsis

Abstract

A series of substituted 4‐methylphenols 1 and 2 was oxidized with PbO~2~ in the presence of nitroso compounds 3–10. The formation of adducts of benzyl radicals with the nitroso spin traps in the reaction mixture was established, suggesting the abstraction of an H‐atom from the methyl substituent of 1 or 2. In the consecutive steps, the adducts underwent a further rearrangement to the corresponding nitrones. When the starting phenol contained bulky ^t^Bu groups in ortho‐position (see 2,6‐di(tert‐butyl)‐4‐methylphenol (1a)), the stable 2,6‐di(tert‐butyl)‐4R‐phenoxy radicals (R=CHN^+^(O^−^)X) were detected as the final radical products. The indirect evidence of nitrones in the reaction mixture was performed in one case by the reaction with a RO$\rm{{_{2}^{{^\cdot} }}}$ radicals.