Asymmetric Syntheses of (Z)- or (E)-β,γ-Unsaturated Ketones via Silane-Controlled Enantiodivergent Catalysis

Cu-catalyzed highly stereoselective and enantiodivergent syntheses of (Z)- or (E)-beta,gamma-unsaturated ketones from 1,3-butadienyl silanes are developed. The nature of the silyl group of the dienes has a significant impact on the stereo- and enantioselectivity of the reactions. Under the developed catalytic systems, the reactions of acyl fluorides with phenyldiemthylsilyl-substituted 1,3-diene gave (Z)-beta,gamma-unsaturated ketones bearing an alpha-tertiary stereogenic center with excellent enantioselectivities and high Z-selectivities, where the reactions with triisopropylsilyl-substituted 1,3-butadiene formed (E)-beta,gamma-unsaturated ketones with high optical purities and excellent E-selectivities. The products generated from the reactions contain three functional groups with orthogonal chemical reactivities, which can undergo a variety of transformations to afford synthetically valuable intermediates.

Automated summary

Highly stereoselective and enantiodivergent syntheses of (Z)- or (E)-beta,gamma-unsaturated ketones from 1,3-butadienyl silanes using Cu catalysts have been developed. The nature of the silyl group of the dienes significantly affects the stereo- and enantioselectivity of the reactions, resulting in the formation of different chiral and stereoselective products.