New Method Of Aromatic Ring Amination With Fluorescent Probes

Combined with an appropriate imaging instrument, fluorescent probes is a sensitive and quantitative method that is widely used in molecular biology and biochemistry laboratories for a variety of experimental, analytical, and quality control applications. They are one of the cornerstones of real-time imaging of live cells and a powerful tool for cell biologists. They provide high sensitivity and great versatility while minimally perturbing the cell under investigation. In this thesis, a series of new fluorescent probes were synthesized and investigated for their applications in ion detection and protein labeling. Furthermore, a novel amination method of aryl triflates was also developed.1. Aryl triflates were effectively converted to the corresponding anilines under the irradiation of microwave in the absence of base or catalyst by using NMP (1-mehyl-2-pyridone) as a solvent. Both electron poor and electron rich substituted aryl triflates gave good yields. The amination was chemospecifically carried out with triflate group when the halide substituted aryl triflates were applied as reactants. The results demonstrated that the microwave-assisted procedure described above provides a facile and efficient methodology for the production of anilines without the need of base or catalyst. The existence of trace of water did not influence the microwave-assisted amination reaction.2. Four novel fluorescein-based fluorescent probes were synthesized. Two of them were investigated for their fluorescent properties in water solution. A significant fluorescent quench was observed when Hg²⁺ was added to the aqueous solution of the probes, providing an ideal "turn-off' fluorescent probes for mercury ions. These probes also exhibited a selective response to Ni²⁺ and hence could be potentially used in labeling proteins or piptides.3. Four fluorescent probe molecules for labeling protein or peptides were designed on the base of fluorescein, aminocoumarin, rhodamine and phenolphthalein as fluorophore. One of them, bis(N-aza-18-crown-6) substituted fluorescein, was synthesized. The preparation of crucial intermediates toward to other probe molecules has also been achieved.