Asymmetric Conjugate Addition of Grignard Reagents to Enones

Significance

The authors reported one of the first successful examples of enantioselective addition to trisubstituted enones. Such addition allows a simple creation of chiral quaternary centers, often difficult to form. This method is especially interesting, as it uses still uncommon chiral NHC ligands for copper in conjunction with Grignard reagents to achieve sufficient addition rates and stereo­control. Even unreactive enones like isophorone can be used in this reaction. Although so far the reported cases are limited to cyclohexanone derivatives, the used synthetic approach is very promising for further developments.