The absolute control of the regiochemistry of a cobalt-catalyzed 1,4-hydrovinylation reaction is achieved by alternation of the ligands applied. While the dppe/dppp ligands led to the formation of the branched product, the herein described application of the SchmalzPhos ligand generates the corresponding linear product in both excellent yields and regioselectivities. The catalyst system exhibits a high tolerance toward functional groups, and the very mild reaction conditions allow the synthesis of 1,4-dienes without isomerization into conjugated systems.
Allylic Oxidation of Ester-Substituted 1,4-Dienes
作者:Lars. E. Sattler、Gerhard Hilt
DOI:10.1021/acs.joc.0c00776
日期:2020.6.5
The cobalt-catalyzed hydrovinylation reaction and the Alder-enereaction generate acyclic 1,4-dienes, which were investigated in the selenium dioxide oxidation to afford further functionalized dienes prone for follow-up reactions. The chemoselective allylic oxidation of ester-functionalized 1,4-dienes occurs at the most electron-rich double bond. The steric demand of the electron-rich, alkyl-substituted