Aliphatic ditopic nitrile N-oxide crosslinker: Synthesis, chemical stability, and catalyst-free crosslinking reactions

Nitrile N-oxides are useful reagents and crosslinkers for catalyst- byproduct-free 1,3-dipolar cycloaddition reactions. The stability of nitrile can be enhanced by introducing bulky substituents, whereas their reactivity decreases concomitantly. Herein, an isolatable aliphatic ditopic N-oxide was synthesized applied to catalyst-free crosslinking unsaturated bond-containing polymers. By decreasing the steric hindrance around moiety compared with a related crosslinker previously developed in our group, operating temperature reaction could lowered. Efficient natural rubber (NR) achieved at 40 °C chloroform give crosslinked NR without formation byproducts. Furthermore, polyacrylonitrile butadiene used as scaffolds efficient solvent-free