Asymmetric Organocatalytic Synthesis of Highly Functionalized Spirocyclohexane Indandiones via a One-Pot Michael/Michael/Aldol Sequence

摘要

The asymmetric organocatalytic one-pot Michael/Michael/ aldol reaction of trifluoromethyl-substituted 1,3-dicarbonyl compounds, nitroolefins, and 2-arylidene indandiones catalyzed sequentially by a cinchona-derived squaramide and DBU leads to spirocyclohexane-indan-1,3-diones bearing five adjacent stereogenic centers including a trifluoromethylated one in medium to very good yields and enantioselectivities, but generally in low to high diastereomeric ratios.