RuO4-mediated oxidation of secondary amines: Part 1. Are hydroxylamines main intermediates?

Abstract

The RuO4-catalyzed oxidation of secondary amines Bn-NH-CH2R (1a-b; R=H, Me) gave mainly amides, but minute amounts of nitrones PhCH=N(O)-CH2R (9a-b) and traces of Bn-N(OH)-CH2R (R=H, 4a) were also detected. In the presence of cyanide, up to 22 reaction products were identified, but mainly α-aminonitriles. Comparison of the oxidation products of 1a-b with those of 4a-b, 9a-b, and Bn-N(O)=CHR (10a-b) showed that 4a-b cannot be main reaction intermediates formed from 1a-b.

Keywords

• oxidation
• secondary amines
• ruthenium tetraoxide
• hydroxyl-amines
• nitrones