formation of functionalized nitrones from N-hydroxyamides was reported. The reaction took place through two types of iridium-catalyzed reactions including dehydrosilylation and hydrosilylation. The method showed high chemoselectivity in the presence of sensitive functional groups, such as methyl esters, and was successfully applied to the synthesis of cyclic and macrocyclic nitrones, which are known to be
报道了 Ir 催化从 N-羟基酰胺还原形成官能化硝酮。该反应通过两种类型的铱催化反应进行,包括脱氢硅烷化和氢化硅烷化。该方法在敏感官能团(如甲酯)的存在下显示出高化学选择性,并成功应用于环状和大环硝酮的合成,已知这些化合物很难通过常规方法获得。(1) H NMR 研究强烈支持生成 N-甲硅烷氧基酰胺和 N,O-缩醛作为实际中间体。
Aza-Henry Reaction with Nitrones, an Under-Explored Transformation
Comprehensive study of the addition of nitroalkanes to nitrones was conducted. The reaction proved efficient with TMAF or TBD as bases, in the presence of a large excess of R–NO2. Phase‐transfer catalysis gave also acceptable yields. Nitroethane or nitropropane afforded mixtures of isomerisable diastereomers. The reaction was applied to the synthesis of biologically relevant compounds.
Hypervalentiodine compounds are viable reagents for the oxidation of N,N-disubstitutedhydroxylamines to the corresponding nitrones, with IBX performing best. The procedure is very simple and user-friendly and affords the target compounds with high efficiency and regioselectivity, highlighting IBX as the reagent of choice for preparation of aldonitrones from nonsymmetric hydroxylamines. Evidence for
A new method for the preparation of nitrones through the aerobic oxidation of the corresponding N,N-disubstituted hydroxylamines has been developed by exploring a new catalytic reactivity of gold supported on silica. The oxidation occurs under very mild conditions (flux of air, methanol or water, room temperature). The oxidation of a range of highly functionalized hydroxylamines with complete conversions
A new green method for the preparation of nitrones through the aerobicoxidation of the corresponding N,N‐disubstituted hydroxylamines has been developed upon exploring the catalytic activity of a diruthenium catalyst, that is, [Ru2(OAc)4Cl]), in aqueous or alcoholic solution under mild reaction conditions (0.1 to 1 mol % catalyst, air, 50 °C) and reasonable reaction times. Notably, the catalytic activity