3‐Hydroxypiperidine scaffolds were enantioselectively constructed in an atom‐economical way by sequentialaction of light and rhodiumupon N‐allylglyoxylamides. In a formal sense, the allylic CH bond was selectively cleaved and enantioselectively added across the ketonic carbonyl group with migration of the double bond (carbonyl‐ene‐type reaction).
Synthesis of Polycyclic Imidazolidinones via Amine Redox-Annulation
作者:Zhengbo Zhu、Xin Lv、Jason E. Anesini、Daniel Seidel
DOI:10.1021/acs.orglett.7b03309
日期:2017.12.1
α-Ketoamides undergo redox-annulations with cyclic secondary amines, such as 1,2,3,4-tetrahydroisoquinoline, pyrrolidine, piperidine, and morpholine. Catalytic amounts of benzoic acid significantly accelerate these transformations. This approach provides polycyclic imidazolidinone derivatives in typically good yields.
The efficient asymmetricsynthesis of highly substituted succinimidesfrom α,β‐unsaturated aldehydes and α‐ketoamides via NHC‐catalyzed [3+2] cycloaddition has been developed. The new scalable protocol significantly expands the utility of NHC catalysis for the synthesis of heterocycles and provides easy access to assemble a wide range of succinimidesfrom simple starting materials.
Asymmetric Synthesis of Chiral 1,3-Diaminopropanols: Bisoxazolidine-Catalyzed CC Bond Formation with α-Keto Amides
作者:Hanhui Xu、Christian Wolf
DOI:10.1002/anie.201105778
日期:2011.12.16
Three high‐yielding steps lead to the formation of chiral 1,3‐diaminopropanols from aliphatic and aromatic α‐keto amides. In this approach, a nitroaldol reaction, which is catalyzed by Cu(SO2CF3)2 and the bisoxazolidine ligand L1, is followed by two mild reduction reactions (see scheme). Laborious protection and deprotection steps can be avoided by using this method.