Acid-catalyzed direct conjugate alkenylation of α,β-unsaturated ketones.
New tricks, old reaction: The title reaction proceeds under mild and transition-metal-free conditions (see scheme; Tf=trifluoromethanesulfonyl). Various combinations of substrates are applicable to the synthesis of γ,δ-unsaturated ketones by employing silicon substituents at the β-position of the enones. The silicon substituents play a key role in stabilization of the cationic intermediate by hyperconjugation.
Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan). kokamoto@scl.kyoto-u.ac.jp.
Kazuhiro
K
Okamoto
Eisuke
E
Tamura
Kouichi
K
Ohe
Lewis acid; conjugate addition; homogeneous catalysis; silicon; synthetic methods