{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:56648"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:56648","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Vanadium-katalysierte, asymmetrische Epoxidierung von Allylalkoholen","abstract":"A protocol for the vanadium-catalysed asymmetric epoxidation of allylic alcohols using enantiopure hydroxamic acids as ligands is described. The newly synthesised hydroxamic acids were derived from bicyclo[2.2.1]heptanes containing chiral centres, as well as from planar chiral [2.2]paracyclophanes and ferrocenes. Best results involving enantioselectivity of the epoxide formation were achieved using ligands with the [2.2]paracyclophane framework. Further studies towards the optimisation of the epoxidation method were carried out, and bulky aliphatic substituents at the nitrogen of the hydroxamic acids were shown to led to an increase in the enantiomeric excess of the products obtained. The readily available tert-butyl hydroperoxide was found to be the oxidant of choice. Environmentally friendly and halide free toluene was used as the solvent. Applying the optimised reaction conditions to the epoxidation of various allylic alcohols containing two or three substituents furnished the corresponding epoxides in good to excellent yields and with an enantiomeric excess of up to 71%.","abstract_html":"A protocol for the vanadium-catalysed asymmetric epoxidation of allylic alcohols using enantiopure hydroxamic acids as ligands is described. The newly synthesised hydroxamic acids were derived from bicyclo[2.2.1]heptanes containing chiral centres, as well as from planar chiral [2.2]paracyclophanes and ferrocenes. Best results involving enantioselectivity of the epoxide formation were achieved using ligands with the [2.2]paracyclophane framework. Further studies towards the optimisation of the epoxidation method were carried out, and bulky aliphatic substituents at the nitrogen of the hydroxamic acids were shown to led to an increase in the enantiomeric excess of the products obtained. The readily available tert-butyl hydroperoxide was found to be the oxidant of choice. Environmentally friendly and halide free toluene was used as the solvent. Applying the optimised reaction conditions to the epoxidation of various allylic alcohols containing two or three substituents furnished the corresponding epoxides in good to excellent yields and with an enantiomeric excess of up to 71%.","abstract_has_math":false,"creators":["Kühn, Toralf"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Bolm, Carsten"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2001,"date_issued":"2001","date_published":"2001","updated_at":"2026-07-30T19:42:01Z","subjects":["info:eu-repo/classification/ddc/540","Chemie","Allylalkohol","Epoxidation","Asymmetrische Reaktion","Vanadiumkomplexe","Imine","Katalysator","Hydroxamsäurederivate","Palladiumkomplexe","Phosphine"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118736%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118736%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118736%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/56648","outbound_label":"Repository record","outbound_source":"dc:identifier"},"source_record":{"url":"https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A56648","prefix":"oai_dc"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Bolm, Carsten"]},{"key":"dc:creator","label":"Author","values":["Kühn, Toralf"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2001"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-2261"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/540","Chemie","Allylalkohol","Epoxidation","Asymmetrische Reaktion","Vanadiumkomplexe","Imine","Katalysator","Hydroxamsäurederivate","Palladiumkomplexe","Phosphine"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/56648","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118736%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["A protocol for the vanadium-catalysed asymmetric epoxidation of allylic alcohols using enantiopure hydroxamic acids as ligands is described. The newly synthesised hydroxamic acids were derived from bicyclo[2.2.1]heptanes containing chiral centres, as well as from planar chiral [2.2]paracyclophanes and ferrocenes. Best results involving enantioselectivity of the epoxide formation were achieved using ligands with the [2.2]paracyclophane framework. Further studies towards the optimisation of the epoxidation method were carried out, and bulky aliphatic substituents at the nitrogen of the hydroxamic acids were shown to led to an increase in the enantiomeric excess of the products obtained. The readily available tert-butyl hydroperoxide was found to be the oxidant of choice. Environmentally friendly and halide free toluene was used as the solvent. Applying the optimised reaction conditions to the epoxidation of various allylic alcohols containing two or three substituents furnished the corresponding epoxides in good to excellent yields and with an enantiomeric excess of up to 71%."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University 225 S. (2001). = Aachen, Techn. Hochsch., Diss., 2001"]},{"key":"dc:title","label":"Title","values":["Vanadium-katalysierte, asymmetrische Epoxidierung von Allylalkoholen"]}]}],"canonical_facts":{"dc:contributor":["Bolm, Carsten"],"dc:coverage":["DE"],"dc:creator":["Kühn, Toralf"],"dc:date":["2001"],"dc:description":["A protocol for the vanadium-catalysed asymmetric epoxidation of allylic alcohols using enantiopure hydroxamic acids as ligands is described. The newly synthesised hydroxamic acids were derived from bicyclo[2.2.1]heptanes containing chiral centres, as well as from planar chiral [2.2]paracyclophanes and ferrocenes. Best results involving enantioselectivity of the epoxide formation were achieved using ligands with the [2.2]paracyclophane framework. Further studies towards the optimisation of the epoxidation method were carried out, and bulky aliphatic substituents at the nitrogen of the hydroxamic acids were shown to led to an increase in the enantiomeric excess of the products obtained. The readily available tert-butyl hydroperoxide was found to be the oxidant of choice. Environmentally friendly and halide free toluene was used as the solvent. Applying the optimised reaction conditions to the epoxidation of various allylic alcohols containing two or three substituents furnished the corresponding epoxides in good to excellent yields and with an enantiomeric excess of up to 71%."],"dc:identifier":["https://publications.rwth-aachen.de/record/56648","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118736%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-2261"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University 225 S. (2001). = Aachen, Techn. 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