{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/70420"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/70420","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Diastereoselectivity of Organometallic Additions to Nitrones","abstract":"Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","abstract_html":"Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","abstract_has_math":false,"creators":["Chang, Zen-Yu"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Coates, Robert M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-15T23:19:21Z","date_published":"2014-12-15T23:19:21Z","updated_at":"2026-07-22T22:26:02Z","subjects":["Chemistry, Organic"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8908646"],"render_values":[{"text":"(UMI)AAI8908646","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/70420","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Coates, Robert M."]},{"key":"dc:creator","label":"Author","values":["Chang, Zen-Yu"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-15T23:19:21Z","10000-01-01","1988"]},{"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":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/70420","(UMI)AAI8908646"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","160 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.","The diastereoselectivity of organometallic additions to nitrones bearing stereogenic substituents has been investigated. High and complementary diastereoselectivity was observed in the additions of Grignard reagents to nitrones (e.g. 62) bearing a potentially chelating $\\beta$-alkoxy group on nitrogen. The high facial diastereoselectivity is explained by a simple chelation model which was supported(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)by $\\sp1$H NMR analysis of a nitrone-magnesium bromide complex (86). However, the opposite selectivity resulted from the reaction of methylmagnesium bromide with the corresponding silyl ether (68). N-Deoxygenation of N,N-dialkylhydroxylamine adducts was achieved by lithium-ammonium reduction of the hydroxylamino carbonates (90 and 95) and phosphates (114). N-Dealkylation by periodic acid cleavage of the resulting amino alcohols (91 and 96) and subsequent hydrolysis of the imine products provided non-racemic chiral amines. The optical purities of the amines were determined by HPLC analyses of their 3,5-dinitrobenzamide derivatives (94 and 97). The relative stereochemistry of selected hydroxylamine adducts was established by N-deoxygenation of the adducts to amines (115), by conversion of the adducts to primary amines, by periodate cleavage of a $\\beta$-hydroxyhydroxylamine (118) and by various correlations. Low selectivity was observed in the organometallic additions to C-($\\alpha$-alkoxy)nitrones (74-76). Organometallic additions to nitrones (70-71) prepared from carbohydrates were also surveyed but further experiments are necessary to explore the potential for chiral amine syntheses by this approach. Formation of tetrahydrooxadiazine dimers in the reactions of N-benzylidene-N-(1-arylalkyl)nitrones with methyllithium was also observed.","Made available in DSpace on 2014-12-15T23:19:21Z (GMT). No. of bitstreams: 1 8908646.pdf: 6204857 bytes, checksum: 1cfe5354d1ec054ccbc6d994822b6165 (MD5) Previous issue date: 1988","Embargo set by: Seth Robbins for item 70586 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs"]},{"key":"dc:title","label":"Title","values":["Diastereoselectivity of Organometallic Additions to Nitrones"]}]}],"canonical_facts":{"dc:contributor":["Coates, Robert M."],"dc:creator":["Chang, Zen-Yu"],"dc:date":["2014-12-15T23:19:21Z","10000-01-01","1988"],"dc:description":["Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","160 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.","The diastereoselectivity of organometallic additions to nitrones bearing stereogenic substituents has been investigated. High and complementary diastereoselectivity was observed in the additions of Grignard reagents to nitrones (e.g. 62) bearing a potentially chelating $\\beta$-alkoxy group on nitrogen. The high facial diastereoselectivity is explained by a simple chelation model which was supported(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)by $\\sp1$H NMR analysis of a nitrone-magnesium bromide complex (86). However, the opposite selectivity resulted from the reaction of methylmagnesium bromide with the corresponding silyl ether (68). N-Deoxygenation of N,N-dialkylhydroxylamine adducts was achieved by lithium-ammonium reduction of the hydroxylamino carbonates (90 and 95) and phosphates (114). N-Dealkylation by periodic acid cleavage of the resulting amino alcohols (91 and 96) and subsequent hydrolysis of the imine products provided non-racemic chiral amines. The optical purities of the amines were determined by HPLC analyses of their 3,5-dinitrobenzamide derivatives (94 and 97). The relative stereochemistry of selected hydroxylamine adducts was established by N-deoxygenation of the adducts to amines (115), by conversion of the adducts to primary amines, by periodate cleavage of a $\\beta$-hydroxyhydroxylamine (118) and by various correlations. Low selectivity was observed in the organometallic additions to C-($\\alpha$-alkoxy)nitrones (74-76). Organometallic additions to nitrones (70-71) prepared from carbohydrates were also surveyed but further experiments are necessary to explore the potential for chiral amine syntheses by this approach. Formation of tetrahydrooxadiazine dimers in the reactions of N-benzylidene-N-(1-arylalkyl)nitrones with methyllithium was also observed.","Made available in DSpace on 2014-12-15T23:19:21Z (GMT). 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