Synthesis of Azaphosphinines by Directed Inverse-Electron-Demand Hetero-Diels-Alder Reactions with Na(OCP).

Herein, a straightforward synthetic approach towards azaphosphinines is reported. The synthesis of 1,3- and 1,4-aza-λ3 -phosphinines as well as 1,2,4-diaza-λ3 -phosphinines by inverse-electron-demand hetero-Diels-Alder reactions of sodium 2-phosphaethynolate [NaOCP] with triazines and tetrazines is studied. In the case of 1,2,4-triazines a hetero-D.A. reaction was developed, which relies on a new directing-group approach based on the complexation of sodium to form an ionic Do→Na-OCP tether. The first X-ray characterization data for aza-λ3 -phosphinines as well as the first phosphinine triflates are presented.