1. Reinvestigation of a catalytic, enantioselective alkene dibromination and chlorohydroxylation, 2. Double cross-coupling reactions of siloxaborolates, 3. The enantioselective synthesis of 3-substituted morpholines using computer-guided catalyst design

In Chapter 1, attempts to reproduce eight, putative, enantioselective dibromination and chlorohydroxylation reactions from oft-cited literature studies are described. The reactions were performed with full fidelity to the original report wherever possible. Analysis of the enantiomeric composition was performed by CSP-HPLC or CSP-SFC, as opposed to the original report, which used chiral shift reagent NMR spectroscopy. After careful study, the reported levels of enantioselectivity were found to be incorrect. Possible explanations for the false positive results are discussed. Chapter 2 moves to a completely different area of chemistry, in the Nobel Prizewinning field of cross-coupling. A bench-stable, crystalline siloxaborolate is described, capable of double cross-coupling reactions to form ortho-teraryls. The initial Suzuki reaction proceeded with high yields but the second, Hiyama-Denmark reaction proved troublesome for coupling with electron-rich aryl bromides, providing only low yields of the desired teraryls. A four-factor DoE study was undertaken to attempt to identify conditions to allow a more general scope for teraryl synthesis, however, these could not be identified in the study. Chapter 3 involves, again, a project very distinct from the other two. This took the form of synthesis and validation of a large, multipurpose set of diverse bisoxazolines of computationally-aided design. This ligand set was tasked with the enantioselective synthesis of C-substituted morpholines, for which a general and highly-selective cyclization has not yet been discovered. A number of ligands were tested for the cyclization of SnAP imines to this purpose, this being a highly general method for morpholine synthesis that previously lacked excellent enantioselectivity, and a broad spread of data was achieved for the purposes of computational modeling.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Carson, Nessa

Contributors dc:contributor

• Denmark, Scott E.

• Chemistry
• Siloxaborolates
• Silylboranes
• Silicon
• Boron
• Cross-coupling
• Hiyama-Denmark
• Suzuki
• Silanolates
• Enantioselective
• Dibromination
• SnAP
• Stannyl amines
• Morpholines
• Bisoxazolines
• Computational
• Modeling
• Cyclization
• Chlorohydroxylation
• Chlorohydrins
• Olefins
• Palladium
• Halofunctionalization
• Dibromides
• Predictive
• Catalytic
• Copper

Statement dc:rights

• © 2016 Nessa Carson

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/95419

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/95419