{"id":{"repo_id":"uno","oai_identifier":"oai:scholarworks.uno.edu:td-1218"},"canonical_url":"https://search.dev.ndltd.org/etd/uno/oai:scholarworks.uno.edu:td-1218","repository":{"repo_id":"uno","name":"University of New Orleans","base_url":"https://scholarworks.uno.edu/do/oai/"},"display":{"title":"Study of Bis-Imidazol-2-Ylidines as Ligands for Transition Metal Catalyzed Coupling Reactions","abstract":"Two bis-imidazol-2-ylidine N-heterocyclic carbenes have been employed as ancillary ligands in an attempt to illustrate their utility in the palladium-mediated preparation of aryl ethers from aryl halides. Ullman-type homo-coupling of the aryl halides persistently occurred instead of ether formation. One of the well known N-heterocyclic carbenes, IPr, was employed with the same results. A variety of reaction conditions and reagents were investigated including solvents, N-heterocyclic carbene species, palladium source, alkoxide base, palladium to ligand ratio and reaction time. Reactivity of the individual N-heterocyclic carbenes as ancillary ligands in the palladium-catalyzed amination reaction of aryl halides was investigated to determine functionality of the carbenes. Alternative procedures to prepare the key intermediates in the synthesis of the bisimidazol- 2-ylidines were developed. In this study the aryl imidazoles were prepared from the corresponding phenol and carbonyldiimidazole. Subsequent N-alkylation then furnished the Nheterocyclic carbenes in high yield. Novel unsymmetrical N-heterocyclic carbenes with aryl and benzylic side groups have been synthesized as models for the subsequent synthesis of unsymmetrical polymer-bound Nheterocyclic carbenes. The unsymmetrical ligands were employed in the palladium-catalyzed amination of aryl halides and in the Suzuki-Miyaura Reaction. Two Merrifield resin polymerbound N-heterocyclic carbene ligands were then synthesized and employed in the aryl amination and Suzuki-Miyaura Reactions. Both reactions were greatly accelerated by the implementation of microwave heating. The Merrifield resin polymer-bound palladium-ligand complexes have been recycled through several reactions without loss of activity.","abstract_html":"Two bis-imidazol-2-ylidine N-heterocyclic carbenes have been employed as ancillary ligands in an attempt to illustrate their utility in the palladium-mediated preparation of aryl ethers from aryl halides. Ullman-type homo-coupling of the aryl halides persistently occurred instead of ether formation. One of the well known N-heterocyclic carbenes, IPr, was employed with the same results. A variety of reaction conditions and reagents were investigated including solvents, N-heterocyclic carbene species, palladium source, alkoxide base, palladium to ligand ratio and reaction time. Reactivity of the individual N-heterocyclic carbenes as ancillary ligands in the palladium-catalyzed amination reaction of aryl halides was investigated to determine functionality of the carbenes. Alternative procedures to prepare the key intermediates in the synthesis of the bisimidazol- 2-ylidines were developed. In this study the aryl imidazoles were prepared from the corresponding phenol and carbonyldiimidazole. Subsequent N-alkylation then furnished the Nheterocyclic carbenes in high yield. Novel unsymmetrical N-heterocyclic carbenes with aryl and benzylic side groups have been synthesized as models for the subsequent synthesis of unsymmetrical polymer-bound Nheterocyclic carbenes. The unsymmetrical ligands were employed in the palladium-catalyzed amination of aryl halides and in the Suzuki-Miyaura Reaction. Two Merrifield resin polymerbound N-heterocyclic carbene ligands were then synthesized and employed in the aryl amination and Suzuki-Miyaura Reactions. Both reactions were greatly accelerated by the implementation of microwave heating. The Merrifield resin polymer-bound palladium-ligand complexes have been recycled through several reactions without loss of activity.","abstract_has_math":false,"creators":["Turnbull, Stanhope"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Trudell, Mark","Jursic, Branko","Wang, G."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2004,"date_issued":"2004-12-17T08:00:00Z","date_published":"2004-12-17T08:00:00Z","updated_at":"2026-07-24T05:28:10Z","subjects":["Polymer-bound imidazol-2-ylidines","Biphenyl","Amination"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.uno.edu/td/214","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Trudell, Mark","Jursic, Branko","Wang, G."]},{"key":"dc:creator","label":"Author","values":["Turnbull, Stanhope"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Polymer-bound imidazol-2-ylidines","Biphenyl","Amination"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.uno.edu/td/214"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Two bis-imidazol-2-ylidine N-heterocyclic carbenes have been employed as ancillary ligands in an attempt to illustrate their utility in the palladium-mediated preparation of aryl ethers from aryl halides. Ullman-type homo-coupling of the aryl halides persistently occurred instead of ether formation. One of the well known N-heterocyclic carbenes, IPr, was employed with the same results. A variety of reaction conditions and reagents were investigated including solvents, N-heterocyclic carbene species, palladium source, alkoxide base, palladium to ligand ratio and reaction time. Reactivity of the individual N-heterocyclic carbenes as ancillary ligands in the palladium-catalyzed amination reaction of aryl halides was investigated to determine functionality of the carbenes. Alternative procedures to prepare the key intermediates in the synthesis of the bisimidazol- 2-ylidines were developed. In this study the aryl imidazoles were prepared from the corresponding phenol and carbonyldiimidazole. Subsequent N-alkylation then furnished the Nheterocyclic carbenes in high yield. Novel unsymmetrical N-heterocyclic carbenes with aryl and benzylic side groups have been synthesized as models for the subsequent synthesis of unsymmetrical polymer-bound Nheterocyclic carbenes. The unsymmetrical ligands were employed in the palladium-catalyzed amination of aryl halides and in the Suzuki-Miyaura Reaction. Two Merrifield resin polymerbound N-heterocyclic carbene ligands were then synthesized and employed in the aryl amination and Suzuki-Miyaura Reactions. Both reactions were greatly accelerated by the implementation of microwave heating. The Merrifield resin polymer-bound palladium-ligand complexes have been recycled through several reactions without loss of activity."]},{"key":"dc:title","label":"Title","values":["Study of Bis-Imidazol-2-Ylidines as Ligands for Transition Metal Catalyzed Coupling Reactions"]}]}],"canonical_facts":{"dc:contributor":["Trudell, Mark","Jursic, Branko","Wang, G."],"dc:creator":["Turnbull, Stanhope"],"dc:description.abstract":["Two bis-imidazol-2-ylidine N-heterocyclic carbenes have been employed as ancillary ligands in an attempt to illustrate their utility in the palladium-mediated preparation of aryl ethers from aryl halides. Ullman-type homo-coupling of the aryl halides persistently occurred instead of ether formation. One of the well known N-heterocyclic carbenes, IPr, was employed with the same results. A variety of reaction conditions and reagents were investigated including solvents, N-heterocyclic carbene species, palladium source, alkoxide base, palladium to ligand ratio and reaction time. Reactivity of the individual N-heterocyclic carbenes as ancillary ligands in the palladium-catalyzed amination reaction of aryl halides was investigated to determine functionality of the carbenes. Alternative procedures to prepare the key intermediates in the synthesis of the bisimidazol- 2-ylidines were developed. In this study the aryl imidazoles were prepared from the corresponding phenol and carbonyldiimidazole. Subsequent N-alkylation then furnished the Nheterocyclic carbenes in high yield. Novel unsymmetrical N-heterocyclic carbenes with aryl and benzylic side groups have been synthesized as models for the subsequent synthesis of unsymmetrical polymer-bound Nheterocyclic carbenes. The unsymmetrical ligands were employed in the palladium-catalyzed amination of aryl halides and in the Suzuki-Miyaura Reaction. Two Merrifield resin polymerbound N-heterocyclic carbene ligands were then synthesized and employed in the aryl amination and Suzuki-Miyaura Reactions. Both reactions were greatly accelerated by the implementation of microwave heating. The Merrifield resin polymer-bound palladium-ligand complexes have been recycled through several reactions without loss of activity."],"dc:identifier":["https://scholarworks.uno.edu/td/214"],"dc:subject":["Polymer-bound imidazol-2-ylidines","Biphenyl","Amination"],"dc:title":["Study of Bis-Imidazol-2-Ylidines as Ligands for Transition Metal Catalyzed Coupling Reactions"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-24T05:28:10Z"}