Mono and double helicenes (M5, M6, D5, and D6) containing six-membered thiopyran rings have been successfully prepared via simultaneous ring expansion and 6-endo cycloisomerizations from the corresponding precursors with five-membered thiophene rings. Although D5 and D6 exhibit similar chemical structures, they demonstrate completely different helical structures because of their distinct steric clashes
含有六元
噻喃环的单螺旋烯和双螺旋烯( M5 、 M6 、 D5和D6 )已通过同时扩环和六元环异构化从相应的五元
噻吩环前体成功制备。尽管D5和D6表现出相似的
化学结构,但由于并入的甲基引起的不同空间冲突,它们表现出完全不同的螺旋结构。此外,所有
噻喃稠合螺烯均表现出覆盖可见光和近红外区域的宽吸收带。