Show simple item record

dc.contributor.authorZaifman, Joshua David
dc.date.accessioned2011-05-17T18:07:54Z
dc.date.available2011-05-17T18:07:54Z
dc.date.issued2011-05-17
dc.identifier.urihttp://hdl.handle.net/10464/3383
dc.description.abstractThis thesis explored the development of several methodologies for the stereoselective construction of ligand frameworks and some of their applications. The first segment concerns the application of an enantioselective lithiation at an Sp3_ hybridized position adjacent to nitrogen by means of the widely used and typically highly effective enantioselective lithiation with ( -)-sparteine. This investigation was intended to develop a method to install chirality into a system that would be converted into a family of diaminoylidenes for use as phosphine mimics in transition metal catalysis or as nucleophilic reagents. Molecular modeling of the system revealed some key interactions between the substrate and (-)-sparteine that provided general insight into the diamine's mode of action and should lend some predictive value to its future applications. The second portion focuses on the development of methods to access 1,2- disubstituted aminoferrocenes, an underexplored class of metallocenes possessing planar chirality. Two routes were examined involving a diastereoselective and an enantioselective pathway, where the latter method made use of the first BF3-mediated lithiation-substitution to install planar chirality. Key derivatives such as 1,2- aminophosphines, made readily accessible by the new route, were evaluated as ligands for Pd(II), Pt(II) and Ir(I). These complexes show activity in a number of transformations with both achiral and prochiral substrates. Optimization experiments were conducted to prepare enantiomerically enriched 2-substituted-I-aminoferrocenes by direct asymmetric lithiation of BF3-coordinated tertiary aminoferrocenes. A predictive computational model describing the transition state of this reaction was developed in collaboration with Professor Travis Dudding's group (Department of Chemistry, Brock University). The predicted stereochemistry of the process was confirmed by single-crystal X-ray analysis of a 2-phosphino-l-dimethylaminoferrocene derivative. Enantiomerically pure samples of the aminophosphine ligands derived from this new process have given promising preliminary results in the enantioselective hydrogenation of prochiral alkenes and warrant further stUdy in metal-mediated catalysis.en_US
dc.language.isoengen_US
dc.publisherBrock Universityen_US
dc.subjectAsymmetric synthesisen_US
dc.subjectCatalysisen_US
dc.titleStereoselective synthesis of substituted hexahydro-3a,4a-diazacyclopentaphenanthren-4-ones and aminoferrocenesen_US
dc.typeElectronic Thesis or Dissertationen_US
dc.degree.namePh.D. Chemistryen_US
dc.degree.levelDoctoralen_US
dc.contributor.departmentDepartment of Chemistryen_US
dc.degree.disciplineFaculty of Mathematics and Scienceen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record