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Liu, Junliang

University of British Columbia

The comprehension, control, and optimization of chemical reactions largely depend on the apt selection of suitable analytical methodologies. For simpler reactions, characterized by straightforward setups and a limited number of reaction components, success can typically be achieved through the combination of standard off-line analytical instruments and established workflows/methodologies. Nonetheless, the situation dramatically changes with the escalation of reaction complexity. This situation becomes particularly prominent in the context of one-pot telescoping type reactions. Such complexities necessitate the development and implementation of more advanced analytical tools and control strategies to ensure the effective study and optimization. This thesis delves into the creation of innovative platforms and methodologies to scrutinize one-pot multistep reaction systems, enabling the control and analysis of these reactions. The work is composed of three distinct studies. The first study focuses on the development of an adaptive auto-synthesizer by merging commercially accessible automated labware and programming language. This auto-synthesizer facilitates the control and standardization of one-pot multistep reactions, accomplished through the integration of orthogonal online reaction monitoring techniques to enable a feedback-control algorithm. In particular, the platform was used to investigate a one-pot two-step carbonyl diimidazole (CDI)-mediated amide bond formation reaction. By adaptively standardizing the reaction conditions, relative rates for the reaction between various carboxylic acids and amines were determined. The second study explored a reliable monitoring methodology for nanocluster (NC) synthesis. Given the complexity of NC synthesis, which usually results in mixtures comprising various species of metal clusters and ligands, existing process analytical technologies (PATs) have proven inadequate for the separation and quantification of each component within the mixture. To address this, I developed a high-performance liquid chromatography (HPLC) separation technique tailored for an N-heterocyclic carbene (NHC)-gold nanocluster (AuNC) mixture. The synthesis of [Au₁₃(NHC)₉Cl₃]Cl₂ and [Au₂₄(NHC)₁₄Cl₂H₃][BF₄]₃ was examined through HPLC monitoring. The third study focused on visualization of the process of one-pot reactions, with those involving non-UV-active and/or unstable reaction components. Two instances are presented in this research. In the first scenario, the research aimed to visualize bio-catalyzed cascade reactions. In the second instance, the study aimed to visualize unstable acyl imidazolide intermediates involved in amidation reactions.

Text

2024-03-15

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87584

Chemistry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/