{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/105593"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/105593","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Enantioselective, Lewis base-catalyzed transformations: I. Polyene sulfenocyclization (preparative and mechanistic aspects) II. Sulfenofunctionalization of alkenyl boronates enabled by 1,2-boronate migration","abstract":"This thesis covers two independent projects which are united under the umbrella of Lewis base catalysis. Following an overview of the key principles behind Lewis base catalysis and how it is used to enhance the electrophilicity of Lewis acids (Chapter 1), the bulk of this thesis will focus on the development of a catalytic, enantioselective sulfenocyclization of polyenes (Chapter 2). Sulfenyl group transfer from a highly reactive, cationic, Lewis acid-base adduct to an unactivated alkene generates a cyclic thiiranium ion, which serves as the initiating event for a highly stereoselective polyene cyclization that is terminated by arenes or phenols. This reaction was enabled by the identification of hexafluoroisopropyl alcohol (HFIP) as a superior solvent which dramatically improves site selectivity of thiiranium ion generation. A broad substrate scope is demonstrated, and the tricyclic products are isolated in good yield and enantioselectivity. Furthermore, a number of functional group interconversions (FGIs) of the resulting thioether moiety are demonstrated. This method is employed for the concise, enantioselective syntheses of the natural products (+)-ferruginol and (+)-hinokiol. Additionally, investigations into the sulfenocyclization of trienes to form even more complex products are disclosed. Preliminary mechanistic experiments to elucidate the rate-determining step of the catalytic cycle and the order in each reaction component were also performed. Chapter 3 of this thesis will cover the development of a Lewis base-catalyzed, enantioselective carbosulfenylation of alkenylboronate complexes which is enabled by a 1,2-boronate migration. The generation of “iranium” ions from alkenylboronates triggers a diastereospecific, ring-opening migration of an alkyl or aryl group to form 1,2-difunctionalized organoboron compounds. This strategy was employed together with Lewis base-catalyzed, enantioselective sulfenyl group transfer to ultimately afford chiral, non-racemic alkylboronic esters in generally high yield, high enantioselectivity, and perfect diastereospecificity. The products of the transformation are useful synthetic intermediates, and a number of useful FGIs are demonstrated.","abstract_html":"This thesis covers two independent projects which are united under the umbrella of Lewis base catalysis. Following an overview of the key principles behind Lewis base catalysis and how it is used to enhance the electrophilicity of Lewis acids (Chapter 1), the bulk of this thesis will focus on the development of a catalytic, enantioselective sulfenocyclization of polyenes (Chapter 2). Sulfenyl group transfer from a highly reactive, cationic, Lewis acid-base adduct to an unactivated alkene generates a cyclic thiiranium ion, which serves as the initiating event for a highly stereoselective polyene cyclization that is terminated by arenes or phenols. This reaction was enabled by the identification of hexafluoroisopropyl alcohol (HFIP) as a superior solvent which dramatically improves site selectivity of thiiranium ion generation. A broad substrate scope is demonstrated, and the tricyclic products are isolated in good yield and enantioselectivity. Furthermore, a number of functional group interconversions (FGIs) of the resulting thioether moiety are demonstrated. This method is employed for the concise, enantioselective syntheses of the natural products (+)-ferruginol and (+)-hinokiol. Additionally, investigations into the sulfenocyclization of trienes to form even more complex products are disclosed. Preliminary mechanistic experiments to elucidate the rate-determining step of the catalytic cycle and the order in each reaction component were also performed. Chapter 3 of this thesis will cover the development of a Lewis base-catalyzed, enantioselective carbosulfenylation of alkenylboronate complexes which is enabled by a 1,2-boronate migration. The generation of “iranium” ions from alkenylboronates triggers a diastereospecific, ring-opening migration of an alkyl or aryl group to form 1,2-difunctionalized organoboron compounds. This strategy was employed together with Lewis base-catalyzed, enantioselective sulfenyl group transfer to ultimately afford chiral, non-racemic alkylboronic esters in generally high yield, high enantioselectivity, and perfect diastereospecificity. The products of the transformation are useful synthetic intermediates, and a number of useful FGIs are demonstrated.","abstract_has_math":false,"creators":["Robb, Kevin Allen"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Smith, Patriann","Trent, William","Brown, Ruth N.","Zimmerman, Steven C.","Stovall, David"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-11-26T20:33:37Z","date_published":"2019-11-26T20:33:37Z","updated_at":"2026-07-22T22:24:44Z","subjects":["Lewis base catalysis","polyene cyclization","alkenylboronates","enantioselective catalysis","olefin sulfenofunctionalization"],"languages":["en"],"rights":["Copyright 2019 Kevin A. Robb"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/105593","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Smith, Patriann","Trent, William","Brown, Ruth N.","Zimmerman, Steven C.","Stovall, David"]},{"key":"dc:creator","label":"Author","values":["Robb, Kevin Allen"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2019-11-26T20:33:37Z","2019-06-05","2019-08"]},{"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":["Lewis base catalysis","polyene cyclization","alkenylboronates","enantioselective catalysis","olefin sulfenofunctionalization"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2019 Kevin A. Robb"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/105593"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis covers two independent projects which are united under the umbrella of Lewis base catalysis. Following an overview of the key principles behind Lewis base catalysis and how it is used to enhance the electrophilicity of Lewis acids (Chapter 1), the bulk of this thesis will focus on the development of a catalytic, enantioselective sulfenocyclization of polyenes (Chapter 2). Sulfenyl group transfer from a highly reactive, cationic, Lewis acid-base adduct to an unactivated alkene generates a cyclic thiiranium ion, which serves as the initiating event for a highly stereoselective polyene cyclization that is terminated by arenes or phenols. This reaction was enabled by the identification of hexafluoroisopropyl alcohol (HFIP) as a superior solvent which dramatically improves site selectivity of thiiranium ion generation. A broad substrate scope is demonstrated, and the tricyclic products are isolated in good yield and enantioselectivity. Furthermore, a number of functional group interconversions (FGIs) of the resulting thioether moiety are demonstrated. This method is employed for the concise, enantioselective syntheses of the natural products (+)-ferruginol and (+)-hinokiol. Additionally, investigations into the sulfenocyclization of trienes to form even more complex products are disclosed. Preliminary mechanistic experiments to elucidate the rate-determining step of the catalytic cycle and the order in each reaction component were also performed. Chapter 3 of this thesis will cover the development of a Lewis base-catalyzed, enantioselective carbosulfenylation of alkenylboronate complexes which is enabled by a 1,2-boronate migration. The generation of “iranium” ions from alkenylboronates triggers a diastereospecific, ring-opening migration of an alkyl or aryl group to form 1,2-difunctionalized organoboron compounds. This strategy was employed together with Lewis base-catalyzed, enantioselective sulfenyl group transfer to ultimately afford chiral, non-racemic alkylboronic esters in generally high yield, high enantioselectivity, and perfect diastereospecificity. The products of the transformation are useful synthetic intermediates, and a number of useful FGIs are demonstrated.","Submission original under an indefinite embargo labeled 'Open Access'. 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Sulfenofunctionalization of alkenyl boronates enabled by 1,2-boronate migration"]}]}],"canonical_facts":{"dc:contributor":["Smith, Patriann","Trent, William","Brown, Ruth N.","Zimmerman, Steven C.","Stovall, David"],"dc:creator":["Robb, Kevin Allen"],"dc:date":["2019-11-26T20:33:37Z","2019-06-05","2019-08"],"dc:description":["This thesis covers two independent projects which are united under the umbrella of Lewis base catalysis. Following an overview of the key principles behind Lewis base catalysis and how it is used to enhance the electrophilicity of Lewis acids (Chapter 1), the bulk of this thesis will focus on the development of a catalytic, enantioselective sulfenocyclization of polyenes (Chapter 2). Sulfenyl group transfer from a highly reactive, cationic, Lewis acid-base adduct to an unactivated alkene generates a cyclic thiiranium ion, which serves as the initiating event for a highly stereoselective polyene cyclization that is terminated by arenes or phenols. This reaction was enabled by the identification of hexafluoroisopropyl alcohol (HFIP) as a superior solvent which dramatically improves site selectivity of thiiranium ion generation. A broad substrate scope is demonstrated, and the tricyclic products are isolated in good yield and enantioselectivity. Furthermore, a number of functional group interconversions (FGIs) of the resulting thioether moiety are demonstrated. This method is employed for the concise, enantioselective syntheses of the natural products (+)-ferruginol and (+)-hinokiol. Additionally, investigations into the sulfenocyclization of trienes to form even more complex products are disclosed. Preliminary mechanistic experiments to elucidate the rate-determining step of the catalytic cycle and the order in each reaction component were also performed. Chapter 3 of this thesis will cover the development of a Lewis base-catalyzed, enantioselective carbosulfenylation of alkenylboronate complexes which is enabled by a 1,2-boronate migration. The generation of “iranium” ions from alkenylboronates triggers a diastereospecific, ring-opening migration of an alkyl or aryl group to form 1,2-difunctionalized organoboron compounds. This strategy was employed together with Lewis base-catalyzed, enantioselective sulfenyl group transfer to ultimately afford chiral, non-racemic alkylboronic esters in generally high yield, high enantioselectivity, and perfect diastereospecificity. The products of the transformation are useful synthetic intermediates, and a number of useful FGIs are demonstrated.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2019-11-26 without embargo terms","The student, Kevin Robb, accepted the attached license on 2019-06-03 at 19:42.","The student, Kevin Robb, submitted this Dissertation for approval on 2019-06-03 at 19:54.","This Dissertation was approved for publication on 2019-06-05 at 11:46.","DSpace SAF Submission Ingestion Package generated from Vireo submission #14016 on 2019-11-26 at 12:49:29","Made available in DSpace on 2019-11-26T20:33:37Z (GMT). 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Sulfenofunctionalization of alkenyl boronates enabled by 1,2-boronate migration"],"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":"2026-07-22T22:24:44Z"}