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|Title:||Fundamental and Applied Studies in Asymmetric Catalysis|
|Author(s):||Fields, Lisa Beattie|
|Doctoral Committee Chair(s):||Jacobsen, Eric N.|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||In Part I of this thesis, a new class of optically active heterobimetallic complexes is described. The complexes L*MCl2 (M = Pt(II), Pd(II), L* = C2-symmetric boron containing bisphosphine ligand) and (Rh(cod)(L*)) ClO4 (cod = eta2,eta 2-1,5-cyclooctadiene) were synthesized as templates for asymmetric catalytic reactions that could involve substrate precoordination to a Lewis acidic site remote from the transition metal reaction site. Primary amines were found to bind reversibly via a nitrogen-boron interaction to the free ligands L*. 1H NMR measurements revealed that the binding constant of representative primary amines to L* could be tuned through variation of the electronic properties of the substituents covalently bound to boron.
In Part II, the asymmetric synthesis of S-(+)-ibuprofen is described. The key asymmetry-inducing step was the catalytic epoxidation of 4-isobutylstyrene using household bleach as the terminal oxidant and chloro- (S,S)-[(2,2 '-((1,2-diphenyl-1,2-ethanediyl)bis(nitrilomethylidyne)) bis (6-(1,1-dimethylethyl)-4-methylphenolato))-N,N ', O,O'] manganese(III) as the catalyst. Enantioselectivities in the range of 50-63% were obtained using this or similar catalysts. The final product was obtained from the epoxide via treatment with trimethylaluminum followed by KMnO 4 oxidation.
In Part III, the use of chiral Mn(III)salen complexes as asymmetric C-H activation catalysts for aryl alkanes was examined. Indanol was obtained from indan in 23% ee using household bleach as the terminal oxidant. Kinetic resolution of benzylic alcohols also occurred under reaction conditions, with enantioselectivities in the range of 2--20%.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1993.
|Date Available in IDEALS:||2014-12-17|