Title: aza-di-π-methane rearrangement
Long Title: IUPAC Gold Book - aza-di-π-methane rearrangement
DOI: 10.1351/goldbook.AT07329
Status: current

Definition
Photochemical reaction of a 1-aza-1,4-diene or a 2-aza-1,4-diene in the triplet excited state to form the corresponding cyclopropylimine.

Note
The rearrangement formally amounts to a 1,2-shift of the imino group and 'bond formation' between the C(3) and C(5) carbon atoms of the azadiene skeleton. 1-Aza-1,4-dienes also undergo the rearrangement to cyclopropylimines using electron-acceptor and electron-donor sensitizers via radical-cation and radical-anion intermediates, respectively. 2-Aza-1,4-dienes rearrange to N-vinylaziridines on irradiation using electron-acceptor sensitizers. In this instance the reaction amounts to a 1,2-shift of the alkene unit and 'bond formation' between the C(1) and C(3) carbon atoms of the azadiene skeleton. 

Related Terms
- Photochemical reaction: https://goldbook.iupac.org//terms/view/P04585
- anion: https://goldbook.iupac.org//terms/view/A00358
- cation: https://goldbook.iupac.org//terms/view/C00907
- di-π-methane rearrangement: https://goldbook.iupac.org//terms/view/D01745
- di-π-silane rearrangement: https://goldbook.iupac.org//terms/view/DT07360
- dienes: https://goldbook.iupac.org//terms/view/D01699
- irradiation: https://goldbook.iupac.org//terms/view/I03255
- oxa-di-π-methane rearrangement: https://goldbook.iupac.org//terms/view/O04359
- rearrangement: https://goldbook.iupac.org//terms/view/R05194
- sensitizers: https://goldbook.iupac.org//terms/view/S05610
- triplet excited state: https://goldbook.iupac.org//terms/view/T06503

Source
- PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 305 (https://doi.org/10.1351/pac200779030293)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/AT07329/html
- json: https://goldbook.iupac.org/terms/view/AT07329/json
- xml: https://goldbook.iupac.org/terms/view/AT07329/xml

Citation: Citation: 'aza-di-π-methane rearrangement' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.AT07329
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Accessed: 2026-05-09T09:31:55+00:00