We present herein a new access to indolizine derivatives involving
1,3-dipolar cycloaddition of pyridinium ylides with phosphorylated
hydroxyketenimines. These ketenimines are easily formed via a Nef-Perkow
cascade involving isocyanides as starting material.
Nef reaction - isocyanide - indolizine - pyridinium
ylide - cycloaddition