cycloaddition reaction was developed for the expedient synthesis of pharmacologically interesting 3-aryl substituted isoxazolines and isoxazoles through C[double bond, length as m-dash]C bond cleavage. Copper nitrate is employed as a reaction promoter and precursor of nitrile oxides. The given approach features a new mode of cycloaddition from olefinic azlactones, copper nitrate and unsaturated compounds
A novel one-pot synthesis of hydroximoyl chlorides and 2-isoxazolines using N-tert-butyl-N-chlorocyanamide
作者:Vinod Kumar、M.P. Kaushik
DOI:10.1016/j.tetlet.2005.12.083
日期:2006.2
Treatment of aldoximes with N-tert-butyl-N-chlorocyanamide gave hydroximoyl chlorides in quantitative yields in less than a minute, which on dehydrohalogenation in the presence of triethylamine gave the corresponding nitrile oxides. The nitrile oxides underwent 1,3-dipolar addition to dipolarophiles and gave 2-isoxazolines in excellent yields under mild conditions. (c) 2005 Elsevier Ltd. All rights reserved.
Koser’s Reagent Mediated Oxidation of Aldoximes: Synthesis of Isoxazolines by 1,3-Dipolar Cycloadditions
approach for the synthesis of isoxazoline derivatives is reported. This protocol involves 1,3-dipolarcycloaddition between in situ generated nitrileoxides from the corresponding aldoximes using [hydroxy(tosyloxy)iodo]benzene (HTIB, Koser’s reagent) and maleimides, styrene and acrylonitrile. The described methodology is very attractive as it is operationally simple, has broad scope, and does not require