Show simple item record

dc.contributor.advisorStephen L. Buchwald.en_US
dc.contributor.authorGribble, Michael William,Jr.en_US
dc.contributor.otherMassachusetts Institute of Technology. Department of Chemistry.en_US
dc.date.accessioned2020-09-15T21:57:17Z
dc.date.available2020-09-15T21:57:17Z
dc.date.copyright2020en_US
dc.date.issued2020en_US
dc.identifier.urihttps://hdl.handle.net/1721.1/127428
dc.descriptionThesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, May, 2020en_US
dc.descriptionCataloged from the official PDF of thesis.en_US
dc.descriptionIncludes bibliographical references.en_US
dc.description.abstractChapter One. Introduction to Catalytic C-C⁻Bond⁻Forming Reactions of Alkylcopper(I) Nucleophiles This chapter provides a brief historical perspective on the development of Cucatalyzed C-C⁻bond-forming reactions and an overview of the general facets of organocopper reactivity that are most important to the work documented in subsequent chapters. Chapter Two: Asymmetric Copper-Hydride-Catalyzed Markovnikov Hydrosilylation of Vinylarenes and Vinyl Heterocycles Copper hydride complexes catalyze highly enantioselective Markovnikov hydrosilylation of vinylarenes and vinyl heterocycles. This method has a broad scope and enables both the synthesis of isolable silanes and the conversion of crude products to chiral alcohols. DFT calculations support a mechanism proceeding by hydrocupration followed by !-bond metathesis with a hydrosilane.en_US
dc.description.abstractChapter Three: Asymmetric Cu-Catalyzed 1,4⁻Dearomatization of Pyridines and Pyridazines without Preactivation of the Heterocycle or Nucleophile. A chiral copper hydride complex catalyzes C-C bond-forming dearomatization of pyridines and pyridazines at room temperature. The catalytic reaction operates directly on free heterocycles and generates the nucleophiles in situ, eliminating the need for stoichiometric preactivation of either reaction partner; further, it is one of very few methods available for the enantioselective 1,4⁻dearomatization of heteroarenes. Combining the dearomatization with facile derivatization steps enables one-pot syntheses of enantioenriched pyridines and piperidines.en_US
dc.description.abstractChapter Four: Evidence for Simultaneous Dearomatization of Two Arenes Under Mild Conditions in Cu(I)-Catalyzed Direct Asymmetric Dearomatization of Pyridine Bis(phosphine) copper hydride complexes are uniquely able to catalyze the direct dearomatization of unactivated pyridines with carbon nucleophiles, but the mechanistic basis for this result has been unclear. Here we show that, contrary to our initial hypotheses, the catalytic mechanism is monometallic and proceeds via dearomative rearrangement of the phenethylcopper nucleophile to a Cparametalated form prior to reaction at heterocycle C4. Our studies support an unexpected heterocycle-promoted pathway for this net 1,5⁻Cu⁻migration beginning with a doubly dearomative imidoyl-Cu-ene reaction. Kinetics, substituent effects, computational modeling, and spectroscopic studies support the involvement of this unusual process.en_US
dc.description.abstractThe CuL₂ fragment subsequently mediates a stepwise Cope rearrangement of the doubly dearomatized intermediate to give the C4⁻ functionalized 1,4-dihydropyridine, lowering a second barrier in the pathway that otherwise prohibit efficient asymmetric catalysis.en_US
dc.description.statementofresponsibilityby Michael W. Gribble, Jr.en_US
dc.format.extent320 pagesen_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsMIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectChemistry.en_US
dc.titleNew fundamental transformations of heterocyclic compounds enabled by copper catalysisen_US
dc.typeThesisen_US
dc.description.degreePh. D.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Chemistryen_US
dc.identifier.oclc1192965329en_US
dc.description.collectionPh.D. Massachusetts Institute of Technology, Department of Chemistryen_US
dspace.imported2020-09-15T21:57:17Zen_US
mit.thesis.degreeDoctoralen_US
mit.thesis.departmentChemen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record