The SRN1 free radical chain reaction of Me3CHgCl with nitronate (−O2NC(R1)(R2)) and phenoneenolate (PHC(0−)C(R1)(R2)) anions yields the C-alkylation products (Me3CC(R1)(R2)N02, PhCOC(R1)(R2)CMe3). Competitive reactions between pairs of anions demonstrate that as the basicity of the anion increases the reactivity toward Me3C at first increases and then decreases. An inverted reactivity order is also
Synthesis of 5-Phosphonoisoxazoline<i>N</i>-Oxides by Selective<i>O</i>-Alkylation of Nitronate Anions
作者:Vincent Perez、Nicolas Rabasso、Antoine Fadel
DOI:10.1002/ejoc.201501243
日期:2016.1
5-phosphonoisoxazoline N-oxides were prepared in good to excellent yields by selective O-alkylation of nitronateanions with (α-tosyloxyvinyl)phosphonates. A comprehensive study was undertaken to limit the competitive formation of the (β-nitrocyclopropyl)phosphonate resulting from C-alkylation of the ambident nitronateanions. The 5-phosphonoisoxazoline N-oxides thus formed were reduced to the corresponding 5-phosphonoisoxazolines