Solvent-Mediated Enantioselective Rauhut-Currier Cyclization via Iminium and Enamine Activation

In this work, we have developed an unconventional and highly enantioselective solvent-promoted Rauhut-Currier cyclization of enal-tethered cyclohexadienone by exploiting the reactivity of a simple Jorgensen-Hayashi catalyst through the merging of iminium and enamine activation. This asymmetric desymmetriza-tion reaction has broad substrate scope in good yields with high to excellent enantioselectivity. DFT calculations suggest that the elimination of the alkoxy group is the rate-limiting step and that it proceeds through proton abstraction by solvent instead of a direct 1,3 -proton shift.

Automated summary

This work presents the development of an unconventional and highly enantioselective solvent-promoted Rauhut-Currier cyclization of enal-tethered cyclohexadienone. The reaction involves the reactivity of a Jorgensen-Hayashi catalyst through the merging of iminium and enamine activation. The asymmetric desymmetrization reaction shows broad substrate scope with good yields and high to excellent enantioselectivity. DFT calculations suggest that the rate-limiting step is the elimination of the alkoxy group, which proceeds through proton abstraction by solvent instead of a direct 1,3-proton shift.