Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9/II, 8010, Graz, Austria.
Department of Chemistry, New York University 100 Washington Square East, New York, NY, 10003, USA.
Chemistry. 2023 Jun 22;29(35):e202300146. doi: 10.1002/chem.202300146. Epub 2023 May 8.
Azo compounds are efficient electron acceptors. Upon one-electron reduction they generally isomerize forming the thermodynamically most stable radical anion. Herein we show that the size of the central ring in 1,2-diazocines and diazonines has a ruling influence on the configuration of the one-electron reduced species. Markedly, diazonines, which bear a central nine membered heterocycle, show light-induced E/Z isomerization, but retain the configuration of the diazene N=N moiety upon one-electron reduction. Accordingly, E/Z isomerization is not induced by reduction.
偶氮化合物是有效的电子受体。在单电子还原后,它们通常会发生异构化,形成热力学上最稳定的自由基阴离子。在此,我们表明 1,2-二氮杂环烯和重氮化合物中环的大小对单电子还原产物的构型具有支配性影响。值得注意的是,带有中央九元杂环的重氮化合物表现出光诱导的 E/Z 异构化,但在单电子还原后保留了重氮 N=N 部分的构型。因此,还原不会诱导 E/Z 异构化。