Synthesis, Structure, and Thermolysis of N‐Apical 1,2λ⁵‐Azaphosphetidines with a Pentacoordinate P Center and the First Observation of Their N‐Equatorial Pseudorotamers

C-apical intermediates are implicated for the first time in the synthesis of olefins by the thermolysis of azaphosphetidines 1. Compound 1 and its pseudorotamer 2 are the first reported azaphosphetidines containing pentacoordinate phosphorus. R = H, CO2Me.