?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F35155%2F&rft.title=The+Rhodium-Catalyzed+Dynamic+Kinetic+Asymmetric+Pauson%E2%88%92Khand+Reaction+of+Allenyl+Carboxy+Esters&rft.creator=Burrows%2C+Lauren&rft.description=The+Rh(I)-catalyzed+allenic+Pauson%E2%88%92Khand+reaction+(APKR)+is+an+efficient%2C+redox-neutral+method+of+synthesizing+%CE%B1-acyloxy+cyclopentenones.+An+enantioselective+APKR+would+provide+access+to+chiral%2C+nonracemic+%CE%B1-acyloxy+and+%CE%B1-hydroxy+cyclopentenones+and+their+corresponding+redox+derivatives.+Rapid+scrambling+of+axial+chirality+of+allenyl+acetates+in+the+presence+of+Rh(I)+catalysts+enables+the+conversion+of+racemic+allene+to+enantiopure+cyclopentenone+product+in+a+Type+I+dynamic+kinetic+asymmetric+transformation+(DyKAT).+A+combined+experimental+and+computational+approach+was+taken+to+develop+an+effective+catalytic+system+to+achieve+the+asymmetric+transformation.+The+optimization+of+the+denticity%2C+and+steric+and+electronic+properties+of+the+ancillary+ligand+(initially+(S)-MonoPhos%2C+16%25+ee)%2C+afforded+a+hemilabile+bidentate+(S)-+MonoPhos-alkene-Rh(I)+catalyst+that+provided+%CE%B1-acyloxy+cyclopentenone+product+in+up+to+72%25+ee.+Upon+discovery+of+the+reactive+and+enantioselective+(S)-MonoPhos-alkene+catalyst%2C+the+remaining+reaction+conditions+were+optimized+using+a+statistical+design+of+experiments+(DOE)+strategy.+Reaction+temperature%2C+CO+atmosphere%2C+catalyst+counteranion%2C+concentration%2C+solvent+identity%2C+additive+equivalents%2C+and+ligand%2FRh+stoichiometry+were+evaluated+simultaneously+in+two+iterations+of+DOE+experimentation.+Discovery+of+optimal+conditions+enabled+an+increase+in+enantioselectivities+and+an+expansion+of+the+APKR+scope+to+include+methyl-substituted+alkynes+and+a+three-carbon-tethered+allene-yne.+The+good+yields+and+enantioselectivities+effected+by+the+phosphoramidite+class+of+ligands+in+the+APKR+inspired+an+exploration+of+electron-deficient+phosphoramidite+ligands+in+the+enantioselective+Pauson%E2%88%92Khand+reaction+(PKR)+of+1%2C6-enynes.+Lowest-energy+reaction+profiles+of+the+cationic+Rh(I)-(R)-BINAP%2C+Rh(I)-(S)-MonoPhos%2C+and+Rh(I)-%E2%80%9CCO-only%E2%80%9D+catalysts+were+calculated%2C+and+agreement+between+experimental+reaction+rates+and+the+activation+energies+of+the+oxidative+cyclization+step+was+found.+We+observed+that+the+PKR+of+cationic+Rh(I)-+catalyst+is+accelerated+3000-fold+in+the+presence+of+(R)-BINAP%2C+and+180-fold+in+the+presence+of+either+one+or+two+(S)-MonoPhos+ligands+(ligand+to+Rh+ratio+of+1.1+or+2.2).+The+absolute+configuration+of+the+PKR+product+was+confirmed+by+VCD+spectroscopy+and+matches+that+predicted+by+calculations.+We+anticipate+that+these+mechanistic+studies+will+enable+the+application+of+phosphoramidite+ligands+in+the+PKR+of+new+enyne+substrates.&rft.date=2018-09-26&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F35155%2F1%2FLaurenBurrowsETD.pdf&rft.identifier=++Burrows%2C+Lauren++(2018)+The+Rhodium-Catalyzed+Dynamic+Kinetic+Asymmetric+Pauson%E2%88%92Khand+Reaction+of+Allenyl+Carboxy+Esters.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++