On the scope of oxidation of tertiary amines: Meisenheimer rearrangements versus Cope elimination in 2-(cyanoethyl)-2-azanorbornanes
In this work, rearrangement reactions subsequent to the oxidation of tertiary amines were studied in 2-(cyanoethyl)-2-azanorbornane/ene systems. [1,2]- and [2,3]-Meisenheimer rearrangements, as well as the Cope elimination reaction, were observed with virtually complete selectivity. It was found that 2-(cyanoethyl)-2-azanorbornanes afford N-hydroxylamines through Cope elimination reactions and 2-(cyanoethyl)-2-azanorbornenes are prone to Meisenheimer rearrangements. In addition, the endo/exo configuration of 2-azanorbornenes plays a key role in the Meisenheimer rearrangement outcome. All the synthesized compounds were fully characterized by NMR spectroscopy and HRMS.