A convenient synthesis of pyrrolo-annelated 1,3-diselenole-2-thione and 1,3-diselenol-2-one derivatives via dipyrrolo-annelated 1,2,5,6-tetraselenocine derivatives

摘要

Figure represented. The reaction of 2,5-dimethyl-3,4-diselenocyanato-1H- pyrrole by NaBH_4 or NaOCH_3 led to tetraselenide 7 in quantitative yield. Treatment of protected tetraselenide 8 with LiAlH 4 afforded the aluminum complex intermediate that was converted into pyrrole-annelated 1,3-diselenolo-2-thione 9 in excellent yield. Similarly, treatment of tetraselenide 8 with LiAlH_4 followed by TFA afforded 1,2-diselenol intermediate that was converted into pyrrole-annelated 1,3-diselenolo-2-one 10 upon treatment of diimidazole carbonate.