The Design, Synthesis And Property Study Of The Fluorescent Nucleoside Modified By Aza-crown

Fluorescent nucleoside analogues have been known for more than three decades. In recent yearsFluorescence spectroscopy, one of the most informative and sensitive analytical techniques, has played andcontinues to play key roles in modern research in biochemistry, and biology and fluorescent nucleoside hasfeature unique chemical property and biological compatibility than other structure. So the application offluorescent analogs was highly concerned. But natural nucleotides can not be used as fluorescent probesbecause of their extremely low quantum yields. So more and more chemists pay attention to the modifiedof the nucleoside and expect to enhance its fluorescence intensity.We design and synthesized the fluorescent nucleoside analogs modified by aza-crown ether. Wemodified the C-8position of nucleoside with electron-withdrawing group to enhance its fluorescenceintensity. It is well known that mercury are readily absorbed by the human GI tract, cross the blood-brainbarrier, and target the central nervous system. Neurological disease associate with mercury intoxicationinclude cognitive and motion disorders, vision and hearing loss and death. So we modified the C-6positionwith aza-crowm ether to complexing the Hg2+. The result of the spectrum experiment show that the probewe design can specific recognize Hg2+among a series of heavy metal ion.Potassium aryltrifluoroborate have received much attention since the discovery of it in1940s. Thisinterest is certainly due to the exceptional stability of them toward oxygen and moisture as compared toother arylboron derivatives. The development of potassium aryltrifluoroborate chemistry in organicsynthesis started with the improvement in their preparation procedures. In fact, the number of publicationdedicated to potassium aryltrifluoroborates chemistry has experienced an exponential growth for the last10years. Those application include in situ generation of RBF2, reaction with electrophiles to preparemercaptan, take part in transition-metal-catalyzed reaction. Especially for the palladium-catalyzed reactioncan be used for the preparation of many useful chemical construction include some medicine.But the development of the synthesis of potassium aryltrifluoroborate was not as rapid as theirapplication. The synthetic method have been reported include isolated boronic acids, transmetalationreaction of aryl halide, C-H bond activation of arene. But all of those must use the material of HF or KHF2 and they can corrosion glass container easily. And all those method reported were two-step reaction or twostep-one pot reaction. As we know there was not report about the preparation of potassiumaryltrifluoroborate by one step.We design and synthesized a new material potassium fluorotetrahydroxydiboron firstly. This materialis mild to glass container and easy to synthesis and purification. Then we achieve the synthesis ofpotassium aryltrifluoroborate in on step reaction by the cross-coulping of potassiumfluorotetrahydroxydiboron and aryl halide.Their structures were confirmed by1H-NMR,13C-NMR,11B-NMR,19F-NMR, HRMS.