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
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.