Sterically crowded triarylphosphines bearing cyano groups
作者:Shigeru Sasaki
DOI:10.1016/j.tetlet.2018.04.065
日期:2018.6
triarylphosphines bearing one, two, and three cyanogroups at 4-positions of aromatic substituents, namely, (4-cyano-2,6-diisopropylphenyl)n(2,4,6-triisopropylphenyl)3–nP (n = 1, 2, 3), were synthesized. Influence of the introduction of cyanogroups is clearly reflected to the oxidation potentials and the fluorescence wavelengths. As the number of cyanogroups increases, the oxidation potentials are raised
Stericallycrowdedtriarylphosphinesbearing anthraquinones were synthesized by Suzuki–Miyaura coupling of arylboronic acids derived from (bromoaryl)phosphines with haloanthraquinones. The anthraquinone bearing the two triarylphosphine moieties at the 2,6-positions shows the smaller difference between the oxidation potential of the triarylphosphine moieties and the reduction potential of the anthraquinone
通过使(溴芳基)膦衍生的芳基硼酸与卤代蒽醌的Suzuki-Miyaura偶联,合成了带有蒽醌的立体拥挤的三芳基膦。在2,6-位带有两个三芳基膦部分的蒽醌显示出三芳基膦基部分的氧化电势与蒽醌部分的还原电势之间的差异较小,而可见红移越多,导致红褐色表示为:与1,5-衍生物相比。通过使用(溴芳基)膦和氯萘醌衍生物衍生的芳基硼酸,通过重复的Suzuki-Miyaura偶联反应,也合成了由三个三芳基膦和四个萘醌部分交替排列组成的空间拥挤的三芳基膦-萘醌低聚物。这低聚物的31 P NMR光谱由窄范围内的几个峰组成,反映了非对映异构体的分布,该非对映异构体的分布是由磷原子上由三个芳环组成的螺旋桨的螺旋线引起的。低聚物呈现出紫色,这是由于分子内电荷从三芳基膦部分转移到相邻的萘醌部分而引起的,并且电荷转移带的波长和强度与氧化还原电位和相邻的三芳基膦–萘醌的数目具有明显的相关性。对。
Synthesis and Properties of Sterically Crowded Triarylphosphines Bearing Naphthoquinone Moieties
Stericallycrowdedtriarylphosphinesbearing naphthoquinone moieties were synthesized by the Suzuki−Miyaura coupling of the corresponding (phosphinoaryl)boronic acid derivatives with 2,3-dichloro-1,4-naphthoquinone. The triarylphosphine−naphthoquinone unit can be extended by employing a triarylphosphinebearing a chloronaphthoquinone moiety as a substrate. As an example, an oligomer bearing three triarylphosphine