Dual Secondary Amine/N-Heterocyclic Carbene Catalysis in the Asymmetric Michael/Cross-Benzoin Cascade Reaction of β-Oxo Sulfones with Enals

Polyfuncionalized cyclopentanones with three contiguous stereogenic centers were formed in good to excellent yields and stereoselectivities by utilizing a secondary amine/N-heterocyclic carbene catalytic system in the reaction of beta-oxo sulfones with unsaturated aldehydes. In addition, the influence of the catalysts on the diastereoselectivity of the final product was studied by H-1 NMR spectroscopy.