The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials (State Key Laboratory Cultivation Base), School of Chemistry and Materials Science, Anhui Normal University , Wuhu 241000, China.
J Org Chem. 2018 Feb 2;83(3):1134-1145. doi: 10.1021/acs.joc.7b02415. Epub 2018 Jan 24.
A series of mono- to hexabrominated BOPHY dyes have been regioselectively synthesized in 41-96% yields from bromination of parent bis(difluoroboron)-1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine (BOPHY), bromination of hydrazine-linked bispyrrole intermediate, or brominated 2-formylpyrrole precursors in moderate to excellent yields. The reactivities of these polybrominated BOPHY dyes were further studied via regioselective nucleophilic substitution or Suzuki/Stille cross-coupling reactions from which a series of 5- or 5,5'-substituted BOPHYs with amine, pyrrole, thiophene, and phenyl groups were obtained in moderate to high yields of 37-94%. The regioselectivities of both the bromination and nucleophilic substitution reaction, and these resultant BOPHY dyes, are confirmed by NMR, HRMS, and crystal structures. The spectroscopic properties of these resultant BOPHYs were studied, and most of them showed strong absorbance and bright fluorescence with maximum wavelengths centered at between the range of 430 and 660 nm. Their absorption and emission spectra were red-shifted for each bromine atom incorporated. The positions in which bromines or substituents are attached modulate the photophysical properties of the resulting BOPHY dyes.
一系列单至六溴代 BOPHY 染料已通过母体双（二氟硼）-1,2-双（（1H-吡咯-2-基）亚甲基）肼（BOPHY）的溴化、肼连接的双吡咯中间体的溴化或溴代 2-甲酰基吡咯前体，以 41-96%的产率进行了区域选择性合成。这些多溴代 BOPHY 染料的反应性通过区域选择性亲核取代或 Suzuki/Stille 交叉偶联反应进一步研究，其中获得了一系列带有胺、吡咯、噻吩和苯基的 5-或 5,5'-取代的 BOPHY，产率为 37-94%。溴化和亲核取代反应的区域选择性，以及这些 BOPHY 染料，通过 NMR、HRMS 和晶体结构得到证实。这些 BOPHY 的光谱性质已被研究，它们中的大多数在 430nm 到 660nm 之间的范围内显示出强烈的吸收和明亮的荧光，最大波长位于该范围内。每个溴原子的加入都使它们的吸收和发射光谱发生红移。溴原子或取代基的位置调节了所得 BOPHY 染料的光物理性质。
