Fig. 7: Proposed reaction mechanism and asymmetric transition state.

CPA catalyzed enolization of ketone as the rate-determining step and the conjugate addition with the α,β-unsaturated iminium as the enantio-determining step.

CPA catalyzed enolization of ketone as the rate-determining step and the conjugate addition with the α,β-unsaturated iminium as the enantio-determining step.