Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
作者:Stefan Haubenreisser、Thorsten H. Wöste、Claudio Martínez、Kazuaki Ishihara、Kilian Muñiz
DOI:10.1002/anie.201507180
日期:2016.1.4
Molecular structures of the most prominent chiral non‐racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen‐bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts
Palladium‐Catalyzed Intermolecular Aryliodination of Internal Alkynes
作者:Yong Ho Lee、Bill Morandi
DOI:10.1002/anie.201812396
日期:2019.5.6
completely atom economical palladium‐catalyzed addition reaction has been developed to stereoselectively access functionalized tetrasubstituted alkenyl iodides. The palladium catalyst, which bears an electron‐poor bidentate ligand rarely employed in catalysis, is essential to promote the high yielding and chemoselective intermolecular reaction between equimolar amounts of an alkyne and an aryl iodide. This
SYNTHESIS – Golden Anniversary Issue Abstract The enantioselective electrochemical lactonization of diketo acid derivatives using chiral iodoarenes as redox mediators is reported for the first time. Good to high stereoselectivities are observed in the lactonization and also in intermolecular α-alkoxylations of diketo ester derivatives. This enantioselective process was then adapted to an electrochemical
Highly Stereoselective Metal-Free Oxyaminations Using Chiral Hypervalent Iodine Reagents
作者:Umar Farid、Thomas Wirth
DOI:10.1002/anie.201107703
日期:2012.4.2
The ring and I: Hypervalentiodine compounds avoid the issues of toxicity or complicated ligands of many transition‐metal‐based systems. A highly enantioselective oxyamination of alkenes with N‐sulfonyl ureas employing chiral, lactic acid‐based hypervalentiodinereagents gives a facile synthesis of enantiomerically pure 2‐arylproline derivatives (see scheme) for the first time.
Enantioselective Kita Oxidative Spirolactonization Catalyzed by In Situ Generated Chiral Hypervalent Iodine(III) Species
作者:Muhammet Uyanik、Takeshi Yasui、Kazuaki Ishihara
DOI:10.1002/anie.200907352
日期:2010.3.15
The iodines(III) have it: The rational design of a conformationally flexible C2‐symmetric iodosylarene catalyst has been used for the enantioselectiveKitaoxidativespirolactonization. The reaction occurs through secondary n–σ* or hydrogen‐bonding interactions between the chiral catalyst and the substrate. Mes=mesityl (2,4,6‐trimethylphenyl).