Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str., 35043 Marburg, Germany.
Org Lett. 2011 Dec 2;13(23):6236-9. doi: 10.1021/ol202696n. Epub 2011 Oct 31.
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.
通过交替使用配体,实现了钴催化的 1,4-氢甲酰化反应的区域化学的绝对控制。虽然 dppe/dppp 配体导致支化产物的形成,但本文所描述的 SchmalzPhos 配体的应用在优异的收率和区域选择性下生成相应的线性产物。该催化剂体系对官能团具有很高的容忍度,并且非常温和的反应条件允许 1,4-二烯的合成而不异构化为共轭体系。