The 1,3-dipolar N-imides of azomethines having the structure
A00562.png
The term azo ylides, derived from the second resonance form, has also been used.
See: imides (2), ylides
Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1321 (https://doi.org/10.1351/pac199567081307)