Competitive photocyclization/rearrangement of 4-aryl-1,1-dicyanobutenes controlled by intramolecular charge-transfer interaction. Effect of medium polarity, temperature, pressure, excitation wavelength, and confinement
作者:Tadashi Ito、Emi Nishiuchi、Gaku Fukuhara、Yoshihisa Inoue、Tadashi Mori
DOI:10.1039/c1pp05038a
日期:2011.9
charge-transfer (C–T) interactions in the ground state. Photoexcitation of these C–T substrates led to competitive cyclization and rearrangement, the ratio being critically controlled by various environmental factors, such as solvent polarity, temperature and static pressure, and also by excitation wavelength and supramolecular confinement (polyethylene voids). In non-polar solvents, the rearrangement was
一系列的4-芳基-1,1-二氰基丁二烯(1a–1f)具有不同的取代基,以控制基态下的分子内供体-受体或电荷转移(C-T)相互作用。这些C-T底物的光激发导致竞争性环化和重排,该比率受各种环境因素(例如溶剂极性,温度和静态压力)以及激发波长和超分子限制(聚乙烯空隙)的严格控制。在非极性溶剂中,对于所有检查的底物,重排都是主要的(> 10:1),而在极性溶剂中,特别是在低温下,环化是有利的。在C–T波段的选择性激发进一步提高了环化率,达到> 50:1的比例。更重要的是,环化/重排比率显示为C–T跃迁能的线性函数。