Rhodium-catalyzed allylation of aldehydes with homoallylic alcohols by retroallylation and isomerization to saturated ketones with conventional or microwave heating.
The treatment of an aldehyde with a tertiary homoallylic alcohol at 100-250 degrees C in the presence of cesium carbonate and a rhodium catalyst leads to allyl transfer from the homoallylic alcohol to the aldehyde. The process includes Rh-mediated retroallylation to form an allyl rhodium species as the key intermediate. The homoallylic alcohol formed initially through allyl transfer is converted under the reaction conditions into the corresponding saturated ketone when bulky ligands are used. Microwave heating at 250 degrees C accelerates the reaction significantly.
Sumida
Yuto
Y
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo, Kyoto 615-8510, Japan.
Takada
Yuko
Y
Hayashi
Sayuri
S
Hirano
Koji
K
Yorimitsu
Hideki
H
Oshima
Koichiro
K