Department of Chemistry, Bengal Engineering and Science University , Shibpur, Howrah 711 103, West Bengal, India.
J Org Chem. 2013 Nov 15;78(22):11184-93. doi: 10.1021/jo401445j. Epub 2013 Nov 4.
s-Tetrazine based molecules were prepared for visible-light-driven organic transformations. The 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) derivative shows visible light absorption and reversible one-electron reduction behavior. In the presence of pytz and aerial oxygen, aldehyde reacts with o-phenylenediamine or o-aminothiophenol under visible light irradiation at ambient temperature to produce corresponding 2-substituted benzimidazoles and benzothiazoles, respectively. Pytz catalyst demonstrates excellent catalytic activity for alkyl, aryl, organo-metallic substituted aldehydes and reducing sugar. The reaction yield is high for both the electron-donating and electron withdrawing substituents in aromatic aldehydes. The use of a metal-free catalyst and visible light energy, along with the mild reaction conditions, makes this reaction an environmentally benign and energy-saving chemical process.
基于 s-四嗪的分子被制备用于可见光驱动的有机转化。3,6-二(吡啶-2-基)-1,2,4,5-四嗪（pytz）衍生物具有可见光吸收和可逆的单电子还原行为。在 pytz 和空气氧的存在下，醛与邻苯二胺或邻氨基噻吩在环境温度下的可见光照射下反应，分别生成相应的 2-取代苯并咪唑和苯并噻唑。pytz 催化剂对烷基、芳基、有机金属取代的醛和还原糖具有优异的催化活性。芳香醛中无论是供电子取代基还是吸电子取代基，反应产率都很高。使用无金属催化剂和可见光能量，以及温和的反应条件，使得该反应成为一种环境友好和节能的化学过程。
