{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/20369"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/20369","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Chiral phosphonyl and thiophosphonyl carbanions in asymmetric alkylation and olefination reactions","abstract":"A series of 3-substituted 2-benzyl-6-methyl-1,3,2-oxazaphosphorinane-2-oxides, derived from (S)-N-alkyl-4-amino-2-butanols, was prepared. The alkylation behavior of the derived lithium anions was examined as a function of the N-substituents and electrophiles. In the l-series, the methylation proceeded with high diastereoselectivity (90/10-97/3) and the benzylation selectivity ranged from 80/20 to 94/6. In the u-series, little steric influence on the methyl selectivity (83/17-85/15) was observed except in the case of sterically demanding group (R = $\\rm C(C\\sb2H\\sb5)\\sb3)$ where high diastereoselectivity (95/5) could be accomplished. An extremely high level of asymmetric induction was achieved in the alkylation of (l)-N-isopropyloxazaphosphorinane-2-oxide with a diverse array of electrophiles. Further extensions to other P-alkyl-N-isopropylphosphonamidates were also examined. Anions derived from enantiomerically enriched N-isopropyloxazaphosphorinane-2-sulfides underwent smooth electrophilic substitution with excellent diastereoselectivity in both l- and u-stereoisomers, which allowed the preparation of scalemic phosphonic acids and phosphonates with three $\\alpha$-substitution patterns (aryl, alkyl, and alkoxy). Synthesis of $\\alpha$-hydroxyphosphonates in either antipodal form could be achieved by the highly diastereoselective alkylation of anions derived from the corresponding P-methoxymethyl analog in the presence of HMPA or PMDTA.","abstract_html":"A series of 3-substituted 2-benzyl-6-methyl-1,3,2-oxazaphosphorinane-2-oxides, derived from (S)-N-alkyl-4-amino-2-butanols, was prepared. The alkylation behavior of the derived lithium anions was examined as a function of the N-substituents and electrophiles. In the l-series, the methylation proceeded with high diastereoselectivity (90/10-97/3) and the benzylation selectivity ranged from 80/20 to 94/6. In the u-series, little steric influence on the methyl selectivity (83/17-85/15) was observed except in the case of sterically demanding group (R = $\\rm C(C\\sb2H\\sb5)\\sb3)$ where high diastereoselectivity (95/5) could be accomplished. An extremely high level of asymmetric induction was achieved in the alkylation of (l)-N-isopropyloxazaphosphorinane-2-oxide with a diverse array of electrophiles. Further extensions to other P-alkyl-N-isopropylphosphonamidates were also examined. Anions derived from enantiomerically enriched N-isopropyloxazaphosphorinane-2-sulfides underwent smooth electrophilic substitution with excellent diastereoselectivity in both l- and u-stereoisomers, which allowed the preparation of scalemic phosphonic acids and phosphonates with three <span class=\"etd-inline-math\">&alpha;</span>-substitution patterns (aryl, alkyl, and alkoxy). Synthesis of <span class=\"etd-inline-math\">&alpha;</span>-hydroxyphosphonates in either antipodal form could be achieved by the highly diastereoselective alkylation of anions derived from the corresponding P-methoxymethyl analog in the presence of HMPA or PMDTA.","abstract_has_math":true,"creators":["Chen, Chien-Tien"],"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":2011,"date_issued":"2011-05-07T12:37:15Z","date_published":"2011-05-07T12:37:15Z","updated_at":"2026-07-22T22:25:15Z","subjects":["Chemistry, Organic"],"languages":["eng"],"rights":["Copyright 1994 Chen, Chien-Tien"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9512324","(UMI)AAI9512324"],"render_values":[{"text":"AAI9512324","href":null,"code":true},{"text":"(UMI)AAI9512324","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/20369","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":["Chen, Chien-Tien"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:37:15Z","10000-01-01","1994"]},{"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 1994 Chen, Chien-Tien"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9512324","(UMI)AAI9512324","http://hdl.handle.net/2142/20369"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["A series of 3-substituted 2-benzyl-6-methyl-1,3,2-oxazaphosphorinane-2-oxides, derived from (S)-N-alkyl-4-amino-2-butanols, was prepared. The alkylation behavior of the derived lithium anions was examined as a function of the N-substituents and electrophiles. In the l-series, the methylation proceeded with high diastereoselectivity (90/10-97/3) and the benzylation selectivity ranged from 80/20 to 94/6. In the u-series, little steric influence on the methyl selectivity (83/17-85/15) was observed except in the case of sterically demanding group (R = $\\rm C(C\\sb2H\\sb5)\\sb3)$ where high diastereoselectivity (95/5) could be accomplished. An extremely high level of asymmetric induction was achieved in the alkylation of (l)-N-isopropyloxazaphosphorinane-2-oxide with a diverse array of electrophiles. Further extensions to other P-alkyl-N-isopropylphosphonamidates were also examined. Anions derived from enantiomerically enriched N-isopropyloxazaphosphorinane-2-sulfides underwent smooth electrophilic substitution with excellent diastereoselectivity in both l- and u-stereoisomers, which allowed the preparation of scalemic phosphonic acids and phosphonates with three $\\alpha$-substitution patterns (aryl, alkyl, and alkoxy). Synthesis of $\\alpha$-hydroxyphosphonates in either antipodal form could be achieved by the highly diastereoselective alkylation of anions derived from the corresponding P-methoxymethyl analog in the presence of HMPA or PMDTA.","The anion derived from scalemic P-benzyl-N-isopropylphosphonamidate added to 4-substituted cyclohexanones with excellent diastereoselectivity. The $\\beta$-hydroxyphosphonamidates were decomposed to alkylidenes with excellent stereospecificity (94%) using a novel electrophile-promoted olefination that employed trityl triflate and 2,6-lutidine in warm acetonitrile. An asymmetric phenylthiomethylidenation also proceeded with high overall selectivity. The alkylidene sulfide underwent highly stereospecific nickel-catalyzed coupling with Grignard and dialkylzinc reagents to produce a variety of dissymmetric olefins.","Made available in DSpace on 2011-05-07T12:37:15Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9512324.pdf: 14210215 bytes, checksum: 03ed87e88e91d67ed11584946bcf445c (MD5) Previous issue date: 1994","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:43:26Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:19:00-05:00 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":["Chiral phosphonyl and thiophosphonyl carbanions in asymmetric alkylation and olefination reactions"]}]}],"canonical_facts":{"dc:contributor":["Denmark, Scott E."],"dc:creator":["Chen, Chien-Tien"],"dc:date":["2011-05-07T12:37:15Z","10000-01-01","1994"],"dc:description":["A series of 3-substituted 2-benzyl-6-methyl-1,3,2-oxazaphosphorinane-2-oxides, derived from (S)-N-alkyl-4-amino-2-butanols, was prepared. The alkylation behavior of the derived lithium anions was examined as a function of the N-substituents and electrophiles. In the l-series, the methylation proceeded with high diastereoselectivity (90/10-97/3) and the benzylation selectivity ranged from 80/20 to 94/6. In the u-series, little steric influence on the methyl selectivity (83/17-85/15) was observed except in the case of sterically demanding group (R = $\\rm C(C\\sb2H\\sb5)\\sb3)$ where high diastereoselectivity (95/5) could be accomplished. An extremely high level of asymmetric induction was achieved in the alkylation of (l)-N-isopropyloxazaphosphorinane-2-oxide with a diverse array of electrophiles. Further extensions to other P-alkyl-N-isopropylphosphonamidates were also examined. Anions derived from enantiomerically enriched N-isopropyloxazaphosphorinane-2-sulfides underwent smooth electrophilic substitution with excellent diastereoselectivity in both l- and u-stereoisomers, which allowed the preparation of scalemic phosphonic acids and phosphonates with three $\\alpha$-substitution patterns (aryl, alkyl, and alkoxy). Synthesis of $\\alpha$-hydroxyphosphonates in either antipodal form could be achieved by the highly diastereoselective alkylation of anions derived from the corresponding P-methoxymethyl analog in the presence of HMPA or PMDTA.","The anion derived from scalemic P-benzyl-N-isopropylphosphonamidate added to 4-substituted cyclohexanones with excellent diastereoselectivity. The $\\beta$-hydroxyphosphonamidates were decomposed to alkylidenes with excellent stereospecificity (94%) using a novel electrophile-promoted olefination that employed trityl triflate and 2,6-lutidine in warm acetonitrile. An asymmetric phenylthiomethylidenation also proceeded with high overall selectivity. The alkylidene sulfide underwent highly stereospecific nickel-catalyzed coupling with Grignard and dialkylzinc reagents to produce a variety of dissymmetric olefins.","Made available in DSpace on 2011-05-07T12:37:15Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9512324.pdf: 14210215 bytes, checksum: 03ed87e88e91d67ed11584946bcf445c (MD5) Previous issue date: 1994","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:43:26Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:19:00-05:00 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":["AAI9512324","(UMI)AAI9512324","http://hdl.handle.net/2142/20369"],"dc:language":["eng"],"dc:rights":["Copyright 1994 Chen, Chien-Tien"],"dc:subject":["Chemistry, Organic"],"dc:title":["Chiral phosphonyl and thiophosphonyl carbanions in asymmetric alkylation and olefination reactions"],"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":"2026-07-22T22:25:15Z"}