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This thesis discusses the applications of protected boronic acids in organic synthesis and radioactive tracer design with focus on N-methyliminodiacetyl (MIDA) ester and organotrifluoroborate. Chapter 2 reviews the work on the capability of acylboronate MIDA esters in Suzuki-Miyaura cross coupling. This is the first study on Suzuki coupling with this motif. A comprehensive screening of conditions was carried out to maximize conversion and yield. Substrate scope centres around the coupling between benzoyl boronates with functionalized aryl bromides, accompanied by the exploration of various alkanoyl boronates and modified aroyl MIDA boronates. Chapter 3 presents a salt metathesis reaction between tetrafluoroborate and boronic acid to generate organotrifluoroborate quantitatively. The appreciable inertness of the tetrafluoroborate anion has left its ability to transfer fluoride onto a fluoride acceptor such as boron uninvestigated. A series of conditions were tested for optimization. Despite difficulty in purification, a quality substrate scope was established with isolated yields for numerous organotrifluoroborates. Visualization of real-time reaction progress by nuclear magnetic resonance spectroscopy, along with kinetic and pH studies, provided mechanistic insight to the process. Chapter 4 focuses on ImMBF₃, a novel radioprosthetic that showed comparable capabilities as the well-established AMBF₃ in prostate cancer imaging. The design stemmed from an observed relationship between organotrifluoroborate stability and the acidity of its carboxylic acid analog. Following a similar synthetic route as AMBF₃, ImMBF₃ was conjugated onto an N₃-Gly derivative of a prostate-specific membrane antigen ligand. Standard ¹⁸F-radiolabelling by isotopic exchange yielded promising radiochemical data in conversion, purity, and activity. Despite increased lipophilicity, imaging and biodistribution studies demonstrated satisfactory in vivo behaviour and tumor to background ratio.

To study the effect of antibiotic stress on wheat seed germination and seedling growth and development, two typical antibiotics-sulfadimidine(SM2) and ciprofloxacin(CIP)-were selected as research objects in this experiment. The effects of the two antibiotics with different concentrations on the growth inhibition rate, seedling biomass, root morphology, and root activity were studied using hydroponics. The ecological toxicity of two antibiotics for wheat seeds was analyzed and compared. The results showed that 0.1~2.0 mg·L-1 SM2 and 0.1~1.0 mg·L-1 CIP could promote the growth of wheat seed roots and buds. However, when the concentration of SM2 reached 10.0 mg·L-1 or the concentration of CIP reached to 5.0 mg·L-1, it began to inhibit the growth of wheat seed roots. The inhibition increased significantly with the concentration. The inhibitory effect of the two antibiotics on the root length of wheat seeds was greater than that on the root length of buds. A low concentration of SM2(0.1 mg·L-1) promoted the growth, dry matter accumulation, and root development of wheat seedlings but with the increased SM2 concentration, the growth of wheat was inhibited, and root biomass and root characteristics(total root length and average diameter) significantly decreased. In the experimental concentration range, CIP inhibited the growth of wheat seedlings, dry matter accumulation, and root characteristics, strengthening with the increase of CIP concentration. In the experimental concentration range, the two antibiotics inhibited the root activity of wheat. With the increase of antibiotic concentration, the redox ability of wheat roots and root activity decreased. In general, SM2 and CIP accumulate continuously in the root system of wheat and affect its normal growth. CIP is relatively more toxic to wheat seedlings, and even 0.1 mg·L-1 CIP can inhibit their growth.