School of Science Department of Chemistry 3 Medicinal Chemistry on Novel Type I1/2 ALK Inhibitors for Combating Drug-resistant Mutants Supervisor: HUANG Yong / CHEM Student: WONG Pui Ying / CHEM Course: UROP 1100, Spring This study explores the NHC-catalyzed asymmetric α-fluorination of carboxylic acid derivatives, which are branched on the α position. Hence shedding light on the unknown reactivity and selectivity of C-F bond construction on α-branched carboxylic acids. In this study, the use of electrophilic fluorination agent, Nfluorobenzenesulfonimide (NFSI) enables F atom installation on the α carbon. While NHC catalyst governs the stereoselectivity leading to formation of optical active α-branched and fluorinated esters. The resulting products provides valuable approach in synthesis of fluorinated compounds from easily accessible carboxylic acid derivatives. Synthesis, Reactivity and Catalytic Properties of Transition Metal Carbyne Complexes Supervisor: JIA Guocheng / CHEM Student: SU Zijie / CHEM Course: UROP 2100, Fall This report focuses on the synthesis of osmabenzyne through the cyclometalation process involving osmium and a specific precursor, namely (Z)-1-triphenylphosphonium-5-(trimethylsilyl)pent-2-en-4-yne tetraphenylborate. The subsequent section will present the synthetic scheme of the desired precursor, followed by detailed discussions on the reaction procedure. The attempted cyclometalation reaction between osmium and the precursor will also be discussed. Despite we encounter the challenges in conducting the experiment and the reaction's failure, the report will thoroughly analyze the causes behind this outcome and offer suggestions to address the encountered problems. Structure, Bonding and Reactivity Studies of Transition-metal Complexes Supervisor: LIN Zhenyang / CHEM Student: TONG Sin Hang / PHYS-IRE Course: UROP 1100, Summer Mechanistic studies unveiled that the activation of N2O using Ni complexes bearing tridentate-bipyridinebased ligand for C(sp2 )-O bond formation may involve a SN2-type attack on O by Ni. Recently, experimental reports showed that similar Ni complexes with bidentate ligands can extend the above reaction to C(sp3 )-O bond formation. In view of the similarities, quantum chemical computational methods were used to verify if the new reaction also follows the same pathway. Calculation results show an alternate mechanism involving electron pair donation from Ni to terminal N of N2O may be more favorable than the proposed SN2-type mechanism. Moreover, it is hinted that there may exist an even more favorable mechanism involving the complex in triplet spin state.
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