{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/84341"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/84341","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Development of a Lewis Base Catalyzed Selenocyclization Reaction","abstract":"\"A variety of chiral, \"\"soft\"\" Lewis base donors were prepared and tested in the selenofunctionalization reaction. An enantioselective process was never realized. Mechanistic investigations have revealed that the seleniranium ion intermediate (which is formed after delivery of the electrophilic selenium source to the olefin, and is the stereodetermining event in this transformation) is configurationally unstable under the reaction conditions. In particular, rapid deselenylation and subsequent racemization of the seleniranium ion has been shown to occur in the presence of alcohol and olefin nucleophiles. Investigations into retarding the rate of racemization of the seleniranium ion intermediate have revealed that electron-poor and sterically encumbered arylselenides are less prone to racemize in the presence of nucleophiles.\"","abstract_html":""A variety of chiral, ""soft"" Lewis base donors were prepared and tested in the selenofunctionalization reaction. An enantioselective process was never realized. Mechanistic investigations have revealed that the seleniranium ion intermediate (which is formed after delivery of the electrophilic selenium source to the olefin, and is the stereodetermining event in this transformation) is configurationally unstable under the reaction conditions. In particular, rapid deselenylation and subsequent racemization of the seleniranium ion has been shown to occur in the presence of alcohol and olefin nucleophiles. Investigations into retarding the rate of racemization of the seleniranium ion intermediate have revealed that electron-poor and sterically encumbered arylselenides are less prone to racemize in the presence of nucleophiles."","abstract_has_math":false,"creators":["Collins, William"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Denmark, Scott E."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T22:14:01Z","date_published":"2015-09-25T22:14:01Z","updated_at":"2026-07-22T22:26:23Z","subjects":["Chemistry, Organic"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI3391917"],"render_values":[{"text":"(MiAaPQ)AAI3391917","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/84341","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Denmark, Scott E."]},{"key":"dc:creator","label":"Author","values":["Collins, William"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T22:14:01Z","10000-01-01","2009"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"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."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemistry, Organic"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/84341","(MiAaPQ)AAI3391917"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["\"A variety of chiral, \"\"soft\"\" Lewis base donors were prepared and tested in the selenofunctionalization reaction. An enantioselective process was never realized. Mechanistic investigations have revealed that the seleniranium ion intermediate (which is formed after delivery of the electrophilic selenium source to the olefin, and is the stereodetermining event in this transformation) is configurationally unstable under the reaction conditions. In particular, rapid deselenylation and subsequent racemization of the seleniranium ion has been shown to occur in the presence of alcohol and olefin nucleophiles. Investigations into retarding the rate of racemization of the seleniranium ion intermediate have revealed that electron-poor and sterically encumbered arylselenides are less prone to racemize in the presence of nucleophiles.\"","Made available in DSpace on 2015-09-25T22:14:01Z (GMT). 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Mechanistic investigations have revealed that the seleniranium ion intermediate (which is formed after delivery of the electrophilic selenium source to the olefin, and is the stereodetermining event in this transformation) is configurationally unstable under the reaction conditions. In particular, rapid deselenylation and subsequent racemization of the seleniranium ion has been shown to occur in the presence of alcohol and olefin nucleophiles. Investigations into retarding the rate of racemization of the seleniranium ion intermediate have revealed that electron-poor and sterically encumbered arylselenides are less prone to racemize in the presence of nucleophiles.\"","Made available in DSpace on 2015-09-25T22:14:01Z (GMT). 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