Thesis advisor: James Morken / This dissertation will present two main projects focusing on the construction of enantiomerically enriched α-boryl organometallic reagents by transition metal catalysis. The first project describes the development of a platinum-catalyzed enantioselective hydrosilylation reaction of alkenyl boronic esters, which provides a general and efficient route to α-borylsilane species. Such species are configurationally stable and exhibit significant synthetic utilities. The second project depicts a nickel-catalyzed enantioselective carbozincation reaction of vinyl boronic esters, which for the first time giving approach to enantioenriched α-borylzinc reagents. These reagents possess good configurational stability at low temperatures and can participate in copper-catalyzed allylation, palladium-catalyzed Negishi cross-coupling and electrophilic halogenation reactions in stereospecific fashion to furnish a broad array of chiral boronic esters. These compounds are important and versatile building blocks in organic synthesis and utilized in the synthesis of (–)-aphanorphine and (–)-enterolactone. Detailed mechanistic studies were carried out, which revealed a nickel(I)-based redox neutral catalytic cycle. The properties of α-borylzinc compounds were also studied by 1H NMR and enabled the development of a stereoconvergent cross-coupling of racemic α-borylzinc reagents. Such catalytic system is also effective for an enantioselective silylzincation of vinyl boronic esters. / Thesis (PhD) — Boston College, 2021. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
| Identifer | oai:union.ndltd.org:BOSTON/oai:dlib.bc.edu:bc-ir_109441 |
| Date | January 2021 |
| Creators | Zhang, Chenlong |
| Publisher | Boston College |
| Source Sets | Boston College |
| Language | English |
| Detected Language | English |
| Type | Text, thesis |
| Format | electronic, application/pdf |
| Rights | Copyright is held by the author, with all rights reserved, unless otherwise noted. |
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