Stereoselective Isoxazolidine Synthesis Via Copper-Catalyzed Alkene Aminooxygenation
作者:Shuklendu D. Karyakarte、Thomas P. Smith、Sherry R. Chemler
DOI:10.1021/jo3013226
日期:2012.9.7
Isoxazolidines are useful in organic synthesis, drug discovery, and chemical biology endeavors. A new stereoselective synthesis of methyleneoxy-substituted isoxazolidines is disclosed. The method involves copper-catalyzed aminooxygenation/cyclization of N-sulfonyl-O-butenyl hydroxylamines in the presence of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl radical (TEMPO) and O2 and provides substituted isoxazolidines
A time-economical and robust synthesis of various selenofunctionalized heterocycles was accomplished via I2O5-mediated selenocyclizations of olefins with diselenides. Using this method, 116 selenomethyl-substituted heterocycles were synthesized with up to 97% isolated yield in minutes. Additional features of this new protocol include the use of an inorganic oxidant, mild conditions, and easy operation
通过I 2 O 5介导的烯烃与二硒化物的硒环化,实现了各种硒官能化杂环的经济且稳健的合成。使用这种方法,在几分钟内合成了 116 个硒甲基取代的杂环,分离产率高达 97%。这个新协议的其他特点包括使用无机氧化剂、温和的条件和易于操作。初步研究表明,这种转化是通过硒基碘诱导的亲电环化进行的。
Palladium-Catalyzed Ring-Forming Alkene Aminoaroylation of Unsaturated Hydrazones and Sulfonamides
The first example of a Pd(OAc)(2)-catalyzed ring-forming alkene aminoaroylation of unsaturated hydrazones and sulfonamides is described. This protocol features the use of diaryliodonium salts as both oxidants and aryl sources, thus enabling mild reaction conditions, good chemoselectivity, a broad substrate scope, and high functional group tolerance. A wide range of synthetically and biologically important functionalized dihydropyrazoles and isoxazolidines have been obtained in good yields.
Visible light-driven photocatalytic generation of sulfonamidyl radicals for alkene hydroamination of unsaturated sulfonamides
A visible light-driven photocatalytic generation of sulfonamidyl radicals, and application to intramolecular alkene hydroamination, has been accomplished.