Efficient and Highly Enantioselective Construction of Trifluoromethylated Quaternary Stereogenic Centers via High-Pressure Mediated Organocatalytic Conjugate Addition of Nitromethane to β,β-Disubstituted Enones
A very effective high-pressure-induced acceleration of asymmetric organocatalyticconjugateaddition of nitromethane to sterically congested β,β-disubstituted β-CF3 enones has been developed. A combination of pressure (8–10 kbar) and noncovalent catalysis with low-loading of chiral tertiary amine-thioureas (0.5–3 mol %) is shown to provide very efficient access to a wide range of γ-nitroketones containing
Ether way: The cinchona‐alkaloid‐catalyzed title reaction was achieved in high yields with high to excellent ee values for the first time, and affords key intermediates for the biologically important 2 having a trifluoromethylated all‐carbon quaternary chiral center. Ether‐type catalysts (1) are more efficient in this transformation than the conventional hydroxy analogues.