Modelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. Smit

The well-defined ruthenium-carbene complexes reported by Grubbs and co-workers were the first ruthenium catalysts to show good activity and selectivity in metathesis of acyclic and cyclic olefins. Unfortunately the use of the Grubbs type catalysts is limited to the small scale synthesis of polymers...

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Main Author: Smit, Frans Johannes
Language:en
Published: North-West University 2012
Subjects:
Online Access:http://hdl.handle.net/10394/5021
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spelling ndltd-NWUBOLOKA1-oai-dspace.nwu.ac.za-10394-50212014-04-16T03:56:43ZModelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. SmitSmit, Frans JohannesRuthenium-carbeneGrubbsHemilabileAlicyclicBidentateN and O chelating ligandsMolecular modellingThe well-defined ruthenium-carbene complexes reported by Grubbs and co-workers were the first ruthenium catalysts to show good activity and selectivity in metathesis of acyclic and cyclic olefins. Unfortunately the use of the Grubbs type catalysts is limited to the small scale synthesis of polymers and essential organic reactions, due to cost and instability of the catalyst at elevated temperatures. Some of the most successful Grubbs-type catalysts included hemilabile ligands. By releasing a free coordination site (the so-called "on-demand-open-site") for an incoming nucleophile, hemilabile ligands have the ability to increase the thermal stability and activity of a catalytic system, by stabilization of the transition metal centre. Previous studies indicated that the incorporation of a sterically hindered N and 0 chelating ligand increased the stability, activity and selectivity of Grubbs type complexes and increasing the electron density of the complex can influence the stability of a complex and therefore the catalytic performance. In this study alicyclic, bidentate N and 0 chelating ligands (16-19) were modelled in order to evaluate the hemilability of these ligands. The modelling was used as a comer stone from which the synthesis was conducted. Molecular modelling showed that of the four ligands identified only two (16 and 18) could potentially be hemilabile. 17 would rather form a transaunular ether compound. The modelling results were incondusive for ligand 19 and further investigation is necessary for this compound…Thesis (M.Sc. (Chemistry))--North-West University, Potchefstroom Campus, 2010.North-West University2012-01-04T13:02:37Z2012-01-04T13:02:37Z2009Thesishttp://hdl.handle.net/10394/5021en
collection NDLTD
language en
sources NDLTD
topic Ruthenium-carbene
Grubbs
Hemilabile
Alicyclic
Bidentate
N and O chelating ligands
Molecular modelling
spellingShingle Ruthenium-carbene
Grubbs
Hemilabile
Alicyclic
Bidentate
N and O chelating ligands
Molecular modelling
Smit, Frans Johannes
Modelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. Smit
description The well-defined ruthenium-carbene complexes reported by Grubbs and co-workers were the first ruthenium catalysts to show good activity and selectivity in metathesis of acyclic and cyclic olefins. Unfortunately the use of the Grubbs type catalysts is limited to the small scale synthesis of polymers and essential organic reactions, due to cost and instability of the catalyst at elevated temperatures. Some of the most successful Grubbs-type catalysts included hemilabile ligands. By releasing a free coordination site (the so-called "on-demand-open-site") for an incoming nucleophile, hemilabile ligands have the ability to increase the thermal stability and activity of a catalytic system, by stabilization of the transition metal centre. Previous studies indicated that the incorporation of a sterically hindered N and 0 chelating ligand increased the stability, activity and selectivity of Grubbs type complexes and increasing the electron density of the complex can influence the stability of a complex and therefore the catalytic performance. In this study alicyclic, bidentate N and 0 chelating ligands (16-19) were modelled in order to evaluate the hemilability of these ligands. The modelling was used as a comer stone from which the synthesis was conducted. Molecular modelling showed that of the four ligands identified only two (16 and 18) could potentially be hemilabile. 17 would rather form a transaunular ether compound. The modelling results were incondusive for ligand 19 and further investigation is necessary for this compound… === Thesis (M.Sc. (Chemistry))--North-West University, Potchefstroom Campus, 2010.
author Smit, Frans Johannes
author_facet Smit, Frans Johannes
author_sort Smit, Frans Johannes
title Modelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. Smit
title_short Modelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. Smit
title_full Modelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. Smit
title_fullStr Modelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. Smit
title_full_unstemmed Modelling and synthesis of alicyclic bidentate n- and o chelating ligands / F.J. Smit
title_sort modelling and synthesis of alicyclic bidentate n- and o chelating ligands / f.j. smit
publisher North-West University
publishDate 2012
url http://hdl.handle.net/10394/5021
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