| Popis: |
Epi-quinine-catalyzed asymmetric nitro-Michael addition of furanones to β,β,-disubstituted nitroalkenes is described. The reaction proceeded smoothly with 1–5 mol % loadings of epi-quinine catalysts at room temperature, giving the corresponding Michael adducts in high yields (72–93%) with extremely high diastereo- and enantioselectivities (>98/2 dr, syn major; 95–99% ee). This reaction provides an effective and straightforward method for constructing all-carbon quaternary stereogenic centers adjacent to oxygen-containing quaternary stereogenic centers. |
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