Substituted Heterocyclic Naphthalene Diimides with Unexpected Acidity. Synthesis, Properties, and Reactivity
作者:Filippo Doria、Marco di Antonio、Michele Benotti、Daniela Verga、Mauro Freccero
DOI:10.1021/jo9017342
日期:2009.11.20
becomes the only detectable species (by UV−vis spectroscopy), in water solution, even under acid conditions (pH 1). In aqueous DMSO the acid/base equilibrium is a function of the DMSO/water ratio. The unexpected acidity of these heterocyclic NDIs, which justifies the reactivity with CH2N2, has been rationalized by DFT computational means [PBE0/6-31+G(d,p)] in aqueous solvent (PCM models) as a result of a
借助包括酰亚胺化在内的分步方案,由2,6-二溴萘和2,3,6,7-四溴萘双氢化物合成了具有杂环1,4-二氢-2,3-吡嗪二酮部分的萘二酰亚胺(NDI),乙烷-1,2-二胺对溴原子的亲核取代,原位还原脱卤和进一步氧化。这些杂环(R =正戊基,环己基)是黄色染料,在有机溶剂中呈绿色发射,其中酸形式占主导。橙色的非荧光共轭碱可以通过在DMSO中添加CH 3 COONBu 4来定量生成,并表现出ap K a= 7.63。即使在酸性条件下(pH 1),共轭碱也成为水溶液中唯一可检测的物种(通过UV-vis光谱法)。在DMSO水溶液中,酸/碱平衡是DMSO /水比率的函数。这些杂环NDI的意想不到的酸度证明了与CH 2 N 2的反应性,已通过DFT计算方法[PBE0 / 6-31 + G(d,p)]在水性溶剂(PCM模型)中得到了合理化。通过包含三个水分子来模拟很强的特异溶剂化作用。