Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, P.R. China.
Analysis and Testing Laboratory, Xinxiang Medical University, Jinsui Road 601, Xinxiang, Henan, 453003, P.R. China.
Chemistry. 2018 Sep 12;24(51):13549-13555. doi: 10.1002/chem.201802157. Epub 2018 Aug 13.
The first example of the synthesis of mono-N,O-B-chelated dipyrromethene (BODIPY) derivatives through an unexpected intramolecular nucleophilic displacement of the fluorine by alkenols in the presence of boron trifluoride as Lewis acid is reported. The chlorine in the indacene core allowed for further structural modifications through nucleophilic substitutions or palladium-catalysed coupling reactions to afford new fluorophores with tuneable photophysical properties. Their expanded conjugation structure resulted in distinct red-shifted absorption and emission spectra in organic solutions. Furthermore, the twisted steric hindrance of the benzene substitution patterns suppressed aggregation-induced quenching, leading to an enhanced NIR emission in the aggregate/solid state, which was rarely observed for BODIPY dyes. Nanoparticles of the fluorophores formed by the assembly with the polymeric surfactant F127 were successfully used for bioimaging of living cells and for tumour-targeted imaging in a tumour-bearing mouse model.
本文报道了首例通过路易斯酸三氟化硼作用下，烯醇的分子内亲核取代反应，合成单 N,O-双螯合二吡咯甲川（BODIPY）衍生物的方法。由于吲达胺核心的氯原子，可通过亲核取代或钯催化偶联反应进一步进行结构修饰，得到具有可调光物理性质的新型荧光团。它们扩展的共轭结构导致在有机溶液中具有明显的红移吸收和发射光谱。此外，苯取代模式的扭曲空间位阻抑制了聚集诱导猝灭，导致在聚集/固态状态下增强了近红外发射，这在 BODIPY 染料中很少观察到。通过与聚合物表面活性剂 F127 组装形成的荧光团纳米粒子，成功地用于活细胞的生物成像和荷瘤小鼠模型中的肿瘤靶向成像。
