Thermodynamic and kinetic factors in the aza-Cope rearrangement of a series of iminium cations

The effects of C–C bond conformation, double bond geometry, and relative stereochemistry on the kinetic and thermodynamic stability of 30 iminium cations as they undergo an aza-Cope rearrangement have been examined via density functional calculations for the purposes of predicting stereoselectivity in the reaction sequence. DFT predicted transition states were consistent with experimentally observed stereoselectivities. The calculations were then extended to the rearrangements of other iminium cations with varying substitution patterns to identify trends in rearrangement pathways. These trends should provide insight into controlling stereoselectivity in this reaction sequence.