Show simple item record

dc.contributor.authorBarnett, David S.en_US
dc.date.accessioned2015-08-07T02:53:58Z
dc.date.available2015-08-07T02:53:58Z
dc.date.issued2013
dc.date.submitted2013
dc.identifier.other(ALMA)contemp
dc.identifier.urihttps://hdl.handle.net/2144/12713
dc.descriptionThesis (Ph.D.)--Boston University PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.en_US
dc.description.abstractAllyl-, allenyl-, and propargylboronate nucleophiles react with carbonyl-containing compounds in a predictable and regioselective manner. Nucleophilic borations using these reagents are known to occur through six-membered transition states, where the carbonyl carbon is activated from the complexation to Lewis acidic boronate species. The ability of boronates to participate in facile and dynamic ligand exchange reactions with chiral alcohols provides opportunity for asymmetric catalysis through the formation of highly reactive chiral boronate nucleophiles in situ. Improved ketone allylborations were achieved using stable cyclic allyldioxaborinanes and BINOLs as chiral catalysts. Enhancement of boronate ligand exchange was revealed through the addition of the sterically hindered Lewis base tert-butanol to promote highly enantioselective allyl- and crotylborations to produce optically enriched tertiary homoallylic alcohols. The asymmetric boronate exchange method was later extended to ketone allenylborations using cyclic allenylboronates with chiral BINOLs to provide tertiary homopropargyl alcohols in excellent enantioselectivities and yields. Cyclic propargylboronates with varying ysubstitutions were then applied to aldehyde allenylborations using vaulted biphenol VANOL as a chiral catalyst in the catalytic boronate exchange method. Propargylborations with dioxaborinanes were determined to be highly enantioselective for a broad range of aldehydes providing various substituted α-allenic alcohols as reaction products.en_US
dc.language.isoen_USen_US
dc.publisherBoston Universityen_US
dc.titleOrganocatalytic boronate exchange methodology for the enantioselective synthesis of alchoholsen_US
dc.typeThesis/Dissertationen_US
etd.degree.nameDoctor of Philosophyen_US
etd.degree.leveldoctoralen_US
etd.degree.disciplineChemistryen_US
etd.degree.grantorBoston Universityen_US


This item appears in the following Collection(s)

Show simple item record