Silica supported sulfuric acid-catalysed one-pot processes for the synthesis of n-heterocycles
- Authors: Ndagano, Urbain Nshokano
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431921 , vital:72815
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Authors: Ndagano, Urbain Nshokano
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431921 , vital:72815
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
Negotiating marginalisation: A socio-economic history of the Kalanga of Mangwe, Zimbabwe, 1940-2015
- Authors: Nyathi, Innocent
- Date: 2022-10-14
- Subjects: Marginalisation , Kalanga (African people) Race identity Zimbabwe , Ethnicity Zimbabwe , Zimbabwe Economic conditions , Zimbabwe Social conditions , Kalanga language (Botswana and Zimbabwe)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/408705 , vital:70518 , DOI 10.21504/10962/408705
- Description: The thesis explores the relationship between ethnicity, marginalisation, and survival mechanisms amongst the Kalanga people of Mangwe (southwestern Zimbabwe) from the 1940s up until the turn of the 21st century. The study showed how the Kalanga of Mangwe have used ethnicity as a concept to not only claim access to resources but also develop alternative survival strategies that help them seek to navigate their experiences of marginalisation by both the state and the hegemonic position of the Ndebele who dominate the region politically and linguistically. Using evidence from activities such as cross border migration and the mopane economy, I showed how the Kalanga express their displeasure at being dominated through engagement, as was shown in their attempt to fight for their language, for example in the 1940s through regionalised Kalanga organisations as the Kalanga Language and Cultural Development Society (KLCDS), to disengagement such as migration and illegal informal cross border trade. Using ‘conviviality’ and ‘the everyday’, as well as borrowing from the Race Relations Theory (RRT) of Robert Ezra Park as theoretical underpinnings, I demonstrated how amongst the Kalanga of Mangwe ethnic identity can lead to competition for resources, which in turn leads to marginalisation and discrimination which influences their social, political and economic choices that may in turn reinforce ethnic identity in a cycle like scenario. Everyday economic and social activities amongst the Kalanga of Mangwe that appear mundane and ordinary to an uninterested observer, help shape the everyday discourse of the Kalanga as they navigate marginalisation. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Authors: Nyathi, Innocent
- Date: 2022-10-14
- Subjects: Marginalisation , Kalanga (African people) Race identity Zimbabwe , Ethnicity Zimbabwe , Zimbabwe Economic conditions , Zimbabwe Social conditions , Kalanga language (Botswana and Zimbabwe)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/408705 , vital:70518 , DOI 10.21504/10962/408705
- Description: The thesis explores the relationship between ethnicity, marginalisation, and survival mechanisms amongst the Kalanga people of Mangwe (southwestern Zimbabwe) from the 1940s up until the turn of the 21st century. The study showed how the Kalanga of Mangwe have used ethnicity as a concept to not only claim access to resources but also develop alternative survival strategies that help them seek to navigate their experiences of marginalisation by both the state and the hegemonic position of the Ndebele who dominate the region politically and linguistically. Using evidence from activities such as cross border migration and the mopane economy, I showed how the Kalanga express their displeasure at being dominated through engagement, as was shown in their attempt to fight for their language, for example in the 1940s through regionalised Kalanga organisations as the Kalanga Language and Cultural Development Society (KLCDS), to disengagement such as migration and illegal informal cross border trade. Using ‘conviviality’ and ‘the everyday’, as well as borrowing from the Race Relations Theory (RRT) of Robert Ezra Park as theoretical underpinnings, I demonstrated how amongst the Kalanga of Mangwe ethnic identity can lead to competition for resources, which in turn leads to marginalisation and discrimination which influences their social, political and economic choices that may in turn reinforce ethnic identity in a cycle like scenario. Everyday economic and social activities amongst the Kalanga of Mangwe that appear mundane and ordinary to an uninterested observer, help shape the everyday discourse of the Kalanga as they navigate marginalisation. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
Synthesis and evaluation of novel heterocycles as potential HIV-1 enzyme inhibitors
- Ngnie Tuemgnie, Gaëlle Tatiana
- Authors: Ngnie Tuemgnie, Gaëlle Tatiana
- Date: 2014
- Subjects: Heterocyclic compounds , Enzyme inhibitors , Organic compounds , Green chemistry , Coumarins , HIV (Viruses) Enzymes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/194293 , vital:45440 , DOI https://doi.org/10.21504/10962/194293
- Description: This project has focussed on the synthesis and the evaluation of organic compounds as potential HIV-1 enzyme inhibitors, by making use of green chemistry (microwave assisted synthesis and click chemistry), palladium catalyzed reactions (Heck and Sonogashira coupling), Baylis Hillman methodology and aldol condensation. These compounds were synthesized in good yields and fully characterised by spectroscopic techniques. Biological assay data revealed that some of the compounds possess high inhibitory activity and their effective inhibitory concentration was as good as those of drugs in clinical use. These potential drug molecules were identified by preliminary investigations carried out by molecular modelling where a trend of their inhibitory activity against different enzymes was anticipated. Benzotriazole-AZT conjugates generated by 1,3-dipolar cycloaddition of anthranilic acid derivatives with AZT showed good inhibitory activity in silico against both HIV-1 protease (PR) and HIV-1 reverse transcriptase (RT) enzymes. Still in line with our dual action strategy, cinnamate ester-AZT conjugates were synthesized in three steps starting from benzaldehyde derivatives with a click reaction at the final step. These compounds also showed some inhibitory activity against HIV-1 RT enzyme (88%). In addition, the cinnamoyl fragment attached to AZT appeared to improve the activity of AZT against HIV-1 RT. Peptide chemistry involving carbonyl diimidazole as a coupling reagent between cinnamic acid derivatives and protected amino acids was used to prepare substituted amino acid derivatives which appeared to be very active against the integrase (IN) enzyme (88%). Commercially available coumarin was iodinated and derivatized through palladium catalyzed Heck and Sonogashira reactions with activated alkenes and a terminal alkyne respectively to afford novel coumarin derivatives in good yields. Optimization studies on the Heck reaction with regards to the phosphine ligand, the palladium catalyst and the solvent were carried out to afford novel formyl substituted cinnamate esters with nonaflyl salicylaldehyde derivatives. , Thesis (PhD) -- Faculty of Science, Chemistry, 2014
- Full Text:
- Authors: Ngnie Tuemgnie, Gaëlle Tatiana
- Date: 2014
- Subjects: Heterocyclic compounds , Enzyme inhibitors , Organic compounds , Green chemistry , Coumarins , HIV (Viruses) Enzymes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/194293 , vital:45440 , DOI https://doi.org/10.21504/10962/194293
- Description: This project has focussed on the synthesis and the evaluation of organic compounds as potential HIV-1 enzyme inhibitors, by making use of green chemistry (microwave assisted synthesis and click chemistry), palladium catalyzed reactions (Heck and Sonogashira coupling), Baylis Hillman methodology and aldol condensation. These compounds were synthesized in good yields and fully characterised by spectroscopic techniques. Biological assay data revealed that some of the compounds possess high inhibitory activity and their effective inhibitory concentration was as good as those of drugs in clinical use. These potential drug molecules were identified by preliminary investigations carried out by molecular modelling where a trend of their inhibitory activity against different enzymes was anticipated. Benzotriazole-AZT conjugates generated by 1,3-dipolar cycloaddition of anthranilic acid derivatives with AZT showed good inhibitory activity in silico against both HIV-1 protease (PR) and HIV-1 reverse transcriptase (RT) enzymes. Still in line with our dual action strategy, cinnamate ester-AZT conjugates were synthesized in three steps starting from benzaldehyde derivatives with a click reaction at the final step. These compounds also showed some inhibitory activity against HIV-1 RT enzyme (88%). In addition, the cinnamoyl fragment attached to AZT appeared to improve the activity of AZT against HIV-1 RT. Peptide chemistry involving carbonyl diimidazole as a coupling reagent between cinnamic acid derivatives and protected amino acids was used to prepare substituted amino acid derivatives which appeared to be very active against the integrase (IN) enzyme (88%). Commercially available coumarin was iodinated and derivatized through palladium catalyzed Heck and Sonogashira reactions with activated alkenes and a terminal alkyne respectively to afford novel coumarin derivatives in good yields. Optimization studies on the Heck reaction with regards to the phosphine ligand, the palladium catalyst and the solvent were carried out to afford novel formyl substituted cinnamate esters with nonaflyl salicylaldehyde derivatives. , Thesis (PhD) -- Faculty of Science, Chemistry, 2014
- Full Text:
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