{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22066"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22066","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Endocyclic restriction test: Determination of a geometrical dependance for an aryl bromide-alkyllithium exchange reaction","abstract":"The geometrical dependance for an aryl bromide-alkyllithium exchange reaction has been investigated by use of the endocyclic restriction test.","abstract_html":"The geometrical dependance for an aryl bromide-alkyllithium exchange reaction has been investigated by use of the endocyclic restriction test.","abstract_has_math":false,"creators":["Allen, David John"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Beak, Peter"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:27:52Z","date_published":"2011-05-07T13:27:52Z","updated_at":"2026-07-22T22:25:19Z","subjects":["Chemistry, Organic"],"languages":["eng"],"rights":["Copyright 1991 Allen, David John"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9136527","(UMI)AAI9136527"],"render_values":[{"text":"AAI9136527","href":null,"code":true},{"text":"(UMI)AAI9136527","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22066","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Beak, Peter"]},{"key":"dc:creator","label":"Author","values":["Allen, David John"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:27:52Z","10000-01-01","1991"]},{"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"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 Allen, David John"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9136527","(UMI)AAI9136527","http://hdl.handle.net/2142/22066"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The geometrical dependance for an aryl bromide-alkyllithium exchange reaction has been investigated by use of the endocyclic restriction test.","There have been four mechanistic alternatives presented for the aryl bromide-alkyllithium exchange reaction: a four-centered transition structure mechanism; a single-electron mediated mechanism; an S$\\sb{\\rm N}$2 attack at bromine; and a pathway involving the formation of a bromine ate complex intermediate. The four-center mechanism proceeds with a small C-Br-C transition structure angle, whereas the S$\\sb{\\rm N}$2 and ate complex formation mechanisms proceed with a large C-Br-C angle. The single-electron transfer mediated mechanism involves dissociation to give bromide and therefore should not have a geometrical dependance in respect to a C-Br-C transition structure angle.","Through double double-label experiments, we have determined that the aryl bromide-alkyllithium exchange of 52 to 53 proceeds intermolecularly in systems in which an intramolecular exchange through a five-, six-, and eight-membered endocyclic ring is available. The exchange will proceed intramolecularly through an eighteen-membered endocyclic ring. This is the first determination of a geometrical dependance for an aryl bromide-alkyllithium exchange.","Through these results, we have ruled out the four-center mechanism, which should proceed intramolecularly though the smaller endocyclic ring systems. The observation of a geometrical dependance also rules out the single-electron transfer mechanism. The mechanistic alternatives which involve large C-Br-C transition structure angles, the S$\\sb{\\rm N}$2 attack at bromine and the bromide ate complex intermediate mechanisms, are supported by our observations.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)","Made available in DSpace on 2011-05-07T13:27:52Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9136527.pdf: 6087651 bytes, checksum: 86f36a5cc2457af4d026bcab97f5cdb7 (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:55:05Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:25:39-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Endocyclic restriction test: Determination of a geometrical dependance for an aryl bromide-alkyllithium exchange reaction"]}]}],"canonical_facts":{"dc:contributor":["Beak, Peter"],"dc:creator":["Allen, David John"],"dc:date":["2011-05-07T13:27:52Z","10000-01-01","1991"],"dc:description":["The geometrical dependance for an aryl bromide-alkyllithium exchange reaction has been investigated by use of the endocyclic restriction test.","There have been four mechanistic alternatives presented for the aryl bromide-alkyllithium exchange reaction: a four-centered transition structure mechanism; a single-electron mediated mechanism; an S$\\sb{\\rm N}$2 attack at bromine; and a pathway involving the formation of a bromine ate complex intermediate. The four-center mechanism proceeds with a small C-Br-C transition structure angle, whereas the S$\\sb{\\rm N}$2 and ate complex formation mechanisms proceed with a large C-Br-C angle. The single-electron transfer mediated mechanism involves dissociation to give bromide and therefore should not have a geometrical dependance in respect to a C-Br-C transition structure angle.","Through double double-label experiments, we have determined that the aryl bromide-alkyllithium exchange of 52 to 53 proceeds intermolecularly in systems in which an intramolecular exchange through a five-, six-, and eight-membered endocyclic ring is available. The exchange will proceed intramolecularly through an eighteen-membered endocyclic ring. This is the first determination of a geometrical dependance for an aryl bromide-alkyllithium exchange.","Through these results, we have ruled out the four-center mechanism, which should proceed intramolecularly though the smaller endocyclic ring systems. The observation of a geometrical dependance also rules out the single-electron transfer mechanism. The mechanistic alternatives which involve large C-Br-C transition structure angles, the S$\\sb{\\rm N}$2 attack at bromine and the bromide ate complex intermediate mechanisms, are supported by our observations.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)","Made available in DSpace on 2011-05-07T13:27:52Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9136527.pdf: 6087651 bytes, checksum: 86f36a5cc2457af4d026bcab97f5cdb7 (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:55:05Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:25:39-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9136527","(UMI)AAI9136527","http://hdl.handle.net/2142/22066"],"dc:language":["eng"],"dc:rights":["Copyright 1991 Allen, David John"],"dc:subject":["Chemistry, Organic"],"dc:title":["Endocyclic restriction test: Determination of a geometrical dependance for an aryl bromide-alkyllithium exchange reaction"],"dc:type":["text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:19Z"}