IMPROVING THE SCOPE AND UNDERSTANDING OF THE SYMMETRIC AND ASYMMETRIC SUZUKI COUPLING REACTION

Watts, Nicola Louisa (2012) IMPROVING THE SCOPE AND UNDERSTANDING OF THE SYMMETRIC AND ASYMMETRIC SUZUKI COUPLING REACTION. Doctoral thesis, University of East Anglia.

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Abstract

Investigations into the Symmetric and Asymmetric Suzuki cross-coupling
reaction have been described. A new reaction protocol has been developed in which
isolated pre-activated sodium trihydroxyarylborate salts were employed as the
organoboron coupling partner, resulting in a more convenient and stoichiometrically
efficient process. This alternative protocol has been applied to symmetric Suzuki
reactions employing simple electron-rich and electron-poor aryl halide partners, and
to sterically challenging Suzuki reactions employing bulkier substrates. Asymmetric
(atroposelective) Suzuki coupling reactions were also successfully performed using
sodium trihydroxyarylborate salts as coupling substrates. The versatility of these
species as general organoboron reagents was also demonstrated by their successful
application in a rhodium-catalysed 1,4-addition reaction.
Experimental studies of asymmetric Suzuki cross-couplings towards axially
chiral biaryl products have also been detailed. Model reactions towards
configurationally stable biaryl products were found to undergo a successful chiral
induction with the use of chiral ferrocenyl ligand (R)-(S)-PPFA 180, with high
enantiomeric excesses achieved in some cases. Investigations into the possible
influences on the asymmetric induction process exerted by the electronic and steric
properties of the coupling partners were carried out, involving repeat asymmetric
reactions towards the biaryl product 1-(2’-nitrophenyl)-2-phenylnaphthalene 179. In
these reactions, changes to the reacting moiety of the coupling substrates were tested,
with an additional reaction carried out involving the reversal of the organic group
borne by each substrate.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Chemistry
Depositing User:	Users 2259 not found.
Date Deposited:	12 Mar 2014 15:03
Last Modified:	12 Mar 2014 15:03
URI:	https://ueaeprints.uea.ac.uk/id/eprint/48116
DOI:

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