Copper-Catalyzed Annulation Reaction of Alkenes and N-Alkyl(aryl)-1-(methylthio)-2-nitroethenamine: an Approach for the Synthesis of Isoxazole Derivatives

Abstract

A copper-catalyzed annulation reaction to access a variety of isoxazoles from alkenes and oxazete in situ generated from N-alkyl­(aryl)-1-(methylthio)-2-nitroethenamine was reported. A plausible mechanism underlying the formation of the product was proposed, which represented a new approach for the construction of isoxazolines. This reaction was capable of tolerating alkenes bearing various substituents, which showed a relatively broad substrate scope with good functional group compatibility.

Nitroenediamines (EDAMs), and N-methyl-1-(methylthio)-2-nitroethenamine (NMSM) derivatives: scaffolds for heterocycle molecular diversity (update from 2012 to 2021)

“…Rong and co-workers established copper-catalyzed construction of various isoxazolines 122 through the 1,3-dipolar cycloaddition reaction of styrene derivatives 116 and 4 H -1,2-oxazete 118 in situ resulting from N -alkyl(aryl)-1-(methylthio)-2-nitroethenamine 4. 30 The tautomerization and combination of substrate 4 with CuCl invited by the amino group generates intermediate 117 that smoothly transforms into intermediate 118. Elimination of methanethion from intermediate 118 makes intermediate 4 H -1,2-oxazete 119 which yields 1,3-dipolar cycloaddition reaction with olefin 116 to obtain target 122 ( Scheme 25 ).…”

Silver-Catalyzed Radical Cascade Sulfonation/Cycloaddition for the Construction of Multifunctional Succimides Containing Separable Z/E-Isomers

“…Until now, the radical cascade sulfonylation/cycloaddition of aza -1,6-enynes has never been achieved. As part of our continuous curiosity about the construction of functional heterocycles, herein we reported the silver-catalyzed radical reaction of aza -1,6-enynes with sodium arylsulfinate (ArSO 2 Na) to furnish sulfonylation succimide containing separable E / Z -configuration isomers (Scheme c).…”

An efficient synthesis of novel isoxazole bearing pyrazole derivatives via [3 + 2] heteroannulation using cupric acetate

“…[ 30–32 ] Thus, 3,5‐disubstituted isoxazole derivatives were obtained by cycloaddition reactions in the presence of catalytic amounts of copper(I) iodide. [ 33 ] Recently, copper‐catalyzed annulation reaction, [ 34 ] Cascade Cyclization [ 35 ] to synthesized variety of isoxazoles have been reported. An efficient [4 + 1] annulation between oximes and sulfur ylides via in situ formation of nitrosoalkenes under mild basic reaction conditions has been developed to synthesize biologically interesting isoxazoline derivatives with good to excellent yields.…”