Department of Synthetic Chemistry and Biological Chemistry, Kyoto University, Katsura, Kyoto, 615-8510, Japan.
Angew Chem Int Ed Engl. 2017 Jun 6;56(24):6989-6993. doi: 10.1002/anie.201702611. Epub 2017 May 10.
(E)-δ-Boryl-substituted anti-homoallylic alcohols are synthesized in a highly diastereo- and enantioselective manner from 1,1-di(boryl)alk-3-enes and aldehydes. Mechanistically, the reaction consists of 1) palladium-catalyzed double-bond transposition of the 1,1-di(boryl)alk-3-enes to 1,1-di(boryl)alk-2-enes, 2) chiral phosphoric acid catalyzed allylation of aldehydes, and 3) palladium-catalyzed geometrical isomerization from the Z to E isomer. As a result, the configurations of two chiral centers and one double bond are all controlled with high selectivity in a single reaction vessel.
（E）-δ-硼取代的反高烯丙醇以高度非对映选择性和对映选择性的方式从 1,1-双（硼烷基）-3-烯和醛合成。从机理上讲，该反应包括 1）钯催化的 1,1-双（硼烷基）-3-烯双键易位到 1,1-双（硼烷基）-2-烯，2）手性磷酸催化的醛烯丙基化，和 3）钯催化的从 Z 到 E 异构体的几何异构化。结果，两个手性中心和一个双键的构型在单个反应容器中都以高选择性控制。
