Print Email Facebook Twitter Transfer hydrogenations and kinetic resolutions Title Transfer hydrogenations and kinetic resolutions Author Klomp, D. Contributor Sheldon, R.A. (promotor) Faculty Applied Sciences Date 2006-03-13 Abstract Chapter 1 is a review on homogeneous transfer hydrogenations. It shows the different reaction mechanisms involved for different types of catalysts. Additionally, the importance of the right choice of hydrogen donors and solvents is discussed. A wide range of compounds can be reduced in this way and the selectivity of these catalysts is very high. Chapter 2 deals with the study of the various mechanisms involved both in the homogeneous and heterogeneous Meerwein-Ponndorf-Verley-Oppenauer reactions catalysed by lanthanide(III) isopropoxides or zeolite Beta. In the homogeneous case, the reaction exclusively takes place via a carbon-to-carbon hydrogen transfer. In the heterogeneous case both a transfer hydrogenation and an elimination/addition pathway are possible depending on the substrate used. Chapter 3 shows the application of homogeneous Meerwein-Ponndorf-Verley-Oppenauer catalysts. A practical racemisation/epimerisation method for chiral secondary alcohols has been developed, which is useful for the recycling of the undesired products of kinetic resolutions of alcohols. Combining a racemisation with an acylation, a straightforward recycling of starting materials may be achieved. Chapter 4 presents the results of the Meerwein-Ponndorf-Verley reduction catalysed by Zr-TUD-1, a newly developed heterogeneous catalyst. This new, three-dimensional silicate containing zirconium was synthesised via a direct hydrothermal treatment method. The activity in the Meerwein-Ponndorf-Verley reduction is strongly dependent on steric factors which can be exploited in the selective reduction of multifunctional steroids. Chapter 5 introduces a new strategy that was developed for the CAL-B catalysed kinetic resolution of tropic acid by which both enantiomers of tropic acid can be obtained in good optical purity. Subject meerwein-ponndorf-verley-oppenauertransfer hydrogenationcatalysishomogeneousheterogeneousmechanismacylationlanthanidezr-tud-1tropic acid To reference this document use: http://resolver.tudelft.nl/uuid:f1444ac0-b944-4bca-8abd-81ea55ff1fc1 ISBN 90-6464-591-4 Part of collection Institutional Repository Document type doctoral thesis Rights (c) 2006 D. Klomp Files PDF as_klomp_20060313.pdf 9.31 MB Close viewer /islandora/object/uuid:f1444ac0-b944-4bca-8abd-81ea55ff1fc1/datastream/OBJ/view