An unprecedented copper nitrate-mediated bondcleavage of alkynes was developed for the modular synthesis of isoxazoles, where either C—Sbond or C≡C triple bond was cleaved selectively. Substituents attached to the C≡C triple bonds could differentiate the chemical bonds cleavage and reaction pathways disparately. Various transformations of products illustrate promising applications of the given protocols
<i>In situ</i> generation of nitrile oxides from copper carbene and <i>tert</i>-butyl nitrite: synthesis of fully substituted isoxazoles
作者:Rongxiang Chen、Abosede Adejoke Ogunlana、Shangwen Fang、Wenhao Long、Hongmei Sun、Xiaoguang Bao、Xiaobing Wan
DOI:10.1039/c8ob01067f
日期:——
Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental