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).
An efficient enantioselective hypervalentiodine promoted oxylactonization of 4-pentenoic acids has been achieved using stoichiometric or a catalytic amount of chiral aryl-λ3-iodane. This reaction provides straightforward access to a wide range of sulfonyloxy- and phosphoryloxy-γ-butyrolactones in respectable yields with moderate to excellent enantioselectivities.