{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/30874"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/30874","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Coordination Chemistry of Bis(diphenylphosphino)amine Ligands with Cobalt Carbonyl and the Intermolecular Catalyzed Pauson-Khand Reaction","abstract":"Bis(diphenylphosphino)amine (PNP) ligands, prepared from (S)-(-)-1-methylbenzyl amine, (-)-cis-myrtanylamine, (S)-(-)-1,1-napthyl(ethyl)amine (PNP1 1a, PNP2 1b, and PNP3 1c respectively) and their cobalt carbonyl complexes are reported. In the absence of alkynes the PNP ligands chelate to the cobalt rather than bridging the two cobalt centers. Although the PNP ligands are chiral the crystal structures are best solved in centrosymmetric space groups with disorder at the chiral carbon with the exception of (PNP3)Co2(CO)6, 2c, which is solved in a non-centrosymmetric space group. When the PNP ligand chelates to cobalt, as in 2, the compounds show activity for the catalytic Pauson-Khand reaction, whereas when the PNP ligand bridges, as in 3, the reaction precedes stiochiometrically. The use of these chiral ligands has not yet resulted in enantioselective catalytic Pauson-Khand cycloadditions. However, a small 15% e.e. was detected for the stiochiometric Pauson-Khand cycloaddition with 3c as the metal substrate.","abstract_html":"Bis(diphenylphosphino)amine (PNP) ligands, prepared from (S)-(-)-1-methylbenzyl amine, (-)-cis-myrtanylamine, (S)-(-)-1,1-napthyl(ethyl)amine (PNP1 1a, PNP2 1b, and PNP3 1c respectively) and their cobalt carbonyl complexes are reported. In the absence of alkynes the PNP ligands chelate to the cobalt rather than bridging the two cobalt centers. Although the PNP ligands are chiral the crystal structures are best solved in centrosymmetric space groups with disorder at the chiral carbon with the exception of (PNP3)Co2(CO)6, 2c, which is solved in a non-centrosymmetric space group. When the PNP ligand chelates to cobalt, as in 2, the compounds show activity for the catalytic Pauson-Khand reaction, whereas when the PNP ligand bridges, as in 3, the reaction precedes stiochiometrically. The use of these chiral ligands has not yet resulted in enantioselective catalytic Pauson-Khand cycloadditions. However, a small 15% e.e. was detected for the stiochiometric Pauson-Khand cycloaddition with 3c as the metal substrate.","abstract_has_math":false,"creators":["Merrill, James Malcolm"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Chemistry","degree_department":"Chemistry","school":null,"contributors":[],"advisors":[],"committee_chairs":["Hanson, Brian E."],"committee_members":["Deck, Paul A.","Dillard, John G."],"year":2001,"date_issued":"2001-12-19","date_published":"2001-12-19","updated_at":"2026-07-22T22:19:41Z","subjects":["phosphine ligands","asymmetric","homogeneous catalysis","Pauson-Khand"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-01102002-163336"],"render_values":[{"text":"etd-01102002-163336","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/30874","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Hanson, Brian E."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Deck, Paul A.","Dillard, John G."]},{"key":"dc:contributor.department","label":"Department","values":["Chemistry"]},{"key":"dc:creator","label":"Author","values":["Merrill, James Malcolm"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:30:20Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:30:20Z","2003-01-11"]},{"key":"dc:date.issued","label":"Date","values":["2001-12-19"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["phosphine ligands","asymmetric","homogeneous catalysis","Pauson-Khand"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-01102002-163336"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/30874"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Bis(diphenylphosphino)amine (PNP) ligands, prepared from (S)-(-)-1-methylbenzyl amine, (-)-cis-myrtanylamine, (S)-(-)-1,1-napthyl(ethyl)amine (PNP1 1a, PNP2 1b, and PNP3 1c respectively) and their cobalt carbonyl complexes are reported. In the absence of alkynes the PNP ligands chelate to the cobalt rather than bridging the two cobalt centers. Although the PNP ligands are chiral the crystal structures are best solved in centrosymmetric space groups with disorder at the chiral carbon with the exception of (PNP3)Co2(CO)6, 2c, which is solved in a non-centrosymmetric space group. When the PNP ligand chelates to cobalt, as in 2, the compounds show activity for the catalytic Pauson-Khand reaction, whereas when the PNP ligand bridges, as in 3, the reaction precedes stiochiometrically. The use of these chiral ligands has not yet resulted in enantioselective catalytic Pauson-Khand cycloadditions. However, a small 15% e.e. was detected for the stiochiometric Pauson-Khand cycloaddition with 3c as the metal substrate."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Coordination Chemistry of Bis(diphenylphosphino)amine Ligands with Cobalt Carbonyl and the Intermolecular Catalyzed Pauson-Khand Reaction"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Hanson, Brian E."],"dc:contributor.committeemember":["Deck, Paul A.","Dillard, John G."],"dc:contributor.department":["Chemistry"],"dc:creator":["Merrill, James Malcolm"],"dc:date.accessioned":["2014-03-14T20:30:20Z"],"dc:date.available":["2014-03-14T20:30:20Z","2003-01-11"],"dc:date.issued":["2001-12-19"],"dc:description.abstract":["Bis(diphenylphosphino)amine (PNP) ligands, prepared from (S)-(-)-1-methylbenzyl amine, (-)-cis-myrtanylamine, (S)-(-)-1,1-napthyl(ethyl)amine (PNP1 1a, PNP2 1b, and PNP3 1c respectively) and their cobalt carbonyl complexes are reported. In the absence of alkynes the PNP ligands chelate to the cobalt rather than bridging the two cobalt centers. Although the PNP ligands are chiral the crystal structures are best solved in centrosymmetric space groups with disorder at the chiral carbon with the exception of (PNP3)Co2(CO)6, 2c, which is solved in a non-centrosymmetric space group. When the PNP ligand chelates to cobalt, as in 2, the compounds show activity for the catalytic Pauson-Khand reaction, whereas when the PNP ligand bridges, as in 3, the reaction precedes stiochiometrically. The use of these chiral ligands has not yet resulted in enantioselective catalytic Pauson-Khand cycloadditions. However, a small 15% e.e. was detected for the stiochiometric Pauson-Khand cycloaddition with 3c as the metal substrate."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-01102002-163336"],"dc:identifier.uri":["http://hdl.handle.net/10919/30874"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["phosphine ligands","asymmetric","homogeneous catalysis","Pauson-Khand"],"dc:title":["Coordination Chemistry of Bis(diphenylphosphino)amine Ligands with Cobalt Carbonyl and the Intermolecular Catalyzed Pauson-Khand Reaction"],"dc:type":["Thesis"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:41Z"}