RuO4-mediated oxidation of secondary amines 2. imines as main reaction intermediates

Abstract

Oxidation by RuO4 (generated in situ from RuO2 and NaIO4) of secondary amines such as Bn–NH–CH2R (1; R=H, Me) gave complex reaction mixtures, but mainly amides. In the presence of cyanide, the leading products were α-aminonitriles. Comparison of the oxidation products of 1 with those from the corresponding imines PhCH=N–CH2R and Bn–N=CH–R showed that formation of the indicated imines is the first main step in the oxidation of 1. A detailed mechanism is proposed.

Keywords

• oxidation
• secondary amines
• ruthenium tetraoxide
• imines
• α-aminonitriles