Self-Assembly Studies of [3]-, [4]-, [5]-, and [6]catenanes

This dissertation, "Self-assembly Studies of [3]-, [4]-, [5]-, and [6]catenanes" by Kai, Wang, 王凱, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled Self-Assembly Studies of [3]-, [4]-, [5]- and [6]Catenanes Submitted by Kai Wang for the Degree of Master of Philosophy at The University of Hong Kong in May 2016 Catenanes are topologically complex molecules consist of two or more interlocked macrocycles. A variety of [2]catenanes have been assembled through different templating strategies but high order [n]catenanes (n>=4) with multiple interlocked rings are very rare. For the assembly of these high order catenanes, special reaction conditions or templates are required while the yields are modest. In order to access to high order catenanes, a strategy that combines ligand preorganization by ii + Cu -coordination and the use of cucurbit[6]uril catalyzed azide-alkyne cycloaddition (CBAAC) as the ring-closing reaction was adopted. It is believed that the stability of Cu -complexed precursor, in conjunction with the highly efficient ring-closing reaction, will result in the facile assembly of desired high order [n]catenanes. In this thesis, [3]-, [4]-, [5]- and [6]catenanes have been assembled in good yields (> 80%) via this strategy and characterized. Chapter 1 gives a brief introduction of catenane. Previously reported assembly strategies of high order [n]catenanes (n>=4), commonly used templates and ring-closing reactions for catenane synthesis are discussed. Chapter 2 describes the design, synthesis, and characterization of the building blocks 1-5, and their self-assembly to [3]-, [4]-, [5]- and [6]catenanes. Careful control of the assembly condition (e.g. concentration), together with preorganization before ring-closing, promoted the assembly of [3]-, [4]-, [5]- and [6]catenanes in good yields (>80%). The assembled catenanes are characterized by NMR and MS experiments. The interlocked nature of assembled structures is demonstrated by NMR studies and further supported by a series of MS experiments. Chapter 3 discusses the synthesis of building block 6 and 7, and their assembly to a [2]catenane using copper-catalyzed alkyne azide cycloaddition (CuAAC). The assembled catenane was preliminarily characterized by MS experiments. Chapter 4 includes experimental details of the syntheses of the building blocks, assembly procedures of the catenanes, NMR and MS spectra, HPLC chromatograms of assembly mixture and UV/Vis spectra. iii Subjects: Catenanes