Paczelt Viktor, Wende Raffael C, Schreiner Peter R, Eckhardt André K
Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392, Giessen, Germany.
Angew Chem Int Ed Engl. 2023 Mar 6;62(11):e202218548. doi: 10.1002/anie.202218548. Epub 2023 Feb 7.
Simple unhindered aldimines tend to hydrolyze or oligomerize and are therefore spectroscopically not well characterized. Herein we report the formation and spectroscopic characterization of the simplest imino acid, namely glycine imine, by cryogenic matrix isolation IR and UV/Vis spectroscopy. Glycine imine forms after UV irradiation of 2-azidoacetic acid by N extrusion in anti-(E,E)- and anti-(Z,Z)-conformation that can be photochemically interconverted. In matrix isolation pyrolysis experiments with 2-azidoacetic acid, glycine imine cannot be trapped as it further decarboxylates to aminomethylene. In aqueous solution glycine imine is hydrolyzed to hydroxy glycine and hydrated glyoxylic acid. At higher concentrations or in the presence of Fe SO as a reducing agent glycine imine undergoes self-reduction by oxidative decarboxylation chemistry. Glycine imine may be seen as one of the key reaction intermediates connecting prebiotic amino acid and sugar formation chemistry.
简单的无阻碍醛亚胺容易水解或齐聚，因此在光谱学上没有很好的表征。在此，我们通过低温基质隔离红外光谱和紫外/可见光谱报告了最简单的亚氨基酸即甘氨酸亚胺的形成及其光谱表征。甘氨酸亚胺是在2-叠氮基乙酸经N消除以反式-(E,E)-和反式-(Z,Z)-构象进行紫外光照射后形成的，这两种构象可进行光化学互变。在2-叠氮基乙酸的基质隔离热解实验中，甘氨酸亚胺无法被捕获，因为它会进一步脱羧生成氨基亚甲基。在水溶液中，甘氨酸亚胺会水解为羟基甘氨酸和水合乙醛酸。在较高浓度下或在作为还原剂的硫酸亚铁存在下，甘氨酸亚胺会通过氧化脱羧化学进行自还原。甘氨酸亚胺可被视为连接益生元氨基酸和糖类形成化学的关键反应中间体之一。
