title: Photochemically Induced Aryl Azide Rearrangement: Solution NMR Spectroscopic Identification of the Rearrangement Product.
abstract: Photolysis of ethyl 3-azido-4,6-difluorobenzoate at room temperature in the presence of oxygen results in the regioselective formation of ethyl 5,7-difluoro-4-azaspiro[2.4]hepta-1,4,6-triene-1-carboxylate, presumably via the corresponding ketenimine intermediate which undergoes a photochemical four-electron electrocyclization followed by a rearrangement. The photorearrangement product was identified by multinuclear solution NMR spectroscopic techniques supported by DFT calculations.
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg , SE-412 96 Gothenburg, Sweden.
authors.forename: Hanna
authors.identifier: 0000-0003-3798-3322
authors.initials: H
authors.lastname: Andersson
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg , SE-412 96 Gothenburg, Sweden.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gräfenstein
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University , Kaohsiung, Taiwan.
authors.forename: Minoru
authors.identifier: 0000-0002-5244-3300
authors.initials: M
authors.lastname: Isobe
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg , SE-412 96 Gothenburg, Sweden.|The Swedish NMR Centre , SE-413 96 Gothenburg, Sweden.
authors.forename: Máté
authors.identifier: 0000-0003-0359-5970
authors.initials: M
authors.lastname: Erdélyi
authors.affiliation: Department of Mathematics and Natural Science, University of Stavanger , NO-4036 Stavanger, Norway.
authors.forename: Magne O
authors.identifier: 0000-0001-9413-6969
authors.initials: MO
authors.lastname: Sydnes