07329 IUPAC Gold Book - aza-di-π-methane rearrangement 10.1351/goldbook.AT07329 AT07329 current 1 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. 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. 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 PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 305 (https://doi.org/10.1351/pac200779030293) https://goldbook.iupac.org/terms/view/AT07329/html https://goldbook.iupac.org/terms/view/AT07329/json https://goldbook.iupac.org/terms/view/AT07329/plain 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 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-05-09T09:30:12+00:00