Formal Ring-Opening/Cross-Coupling Reactions of 2-Pyrones: Iron-Catalyzed Entry into Stereodefined Dienyl Carboxylates
作者:Chang-Liang Sun、Alois Fürstner
DOI:10.1002/anie.201307028
日期:2013.12.2
exceptional level of sophistication in cross‐coupling chemistry, reactions of substrates that incorporate the leaving group as an integral part into a heterocyclic scaffold are scarce. The title reaction outlines the utility of this reaction format (see scheme; acac=acetylacetonate), provides a convenient entry into stereodefined diene carboxylates, and adds a new chapter to the field of iron catalysis.
Iron‐Catalyzed Reactions of 2‐Pyridone Derivatives: 1,6‐Addition and Formal Ring Opening/Cross Coupling
作者:Lin Huang、Yiting Gu、Alois Fürstner
DOI:10.1002/asia.201900865
日期:2019.11.18
In the presence of simple iron salts, 2-pyridone derivatives react with Grignard reagents under mild conditions to give the corresponding 1,6-addition products; if the reaction medium is supplemented with an aprotic dipolar cosolvent after the actual addition step, the intermediates primarily formed succumb to ring opening, giving rise to non-thermodynamic Z,E-configured dienoic acid amide derivatives
A long-existing problem of cyclohexane-1,3-dione derivatives (CDD) synthesis from unreactive acetone through consecutive Michael-Claisen process was solved under this study. The practical applicability of this process was tested for a novel compound ethyl 3-(2,4-dioxocyclohexyl) propanoate for up to 20-gram scale. Furthermore, the scope of different acetone derivatives was investigated and resulted with similar consecutive Michael-Claisen process for CDD synthesis. The reaction exhibited remarkable regioselectivity in Michael addition followed by Claisen cyclization. In this process high substrate selectivity was observed for CDD synthesis following consecutive double-Michael-Claisen and Michael-Claisen cyclization.
Colonge,J.; Varagnat,J., Bulletin de la Societe Chimique de France, 1961, p. 237 - 239