Title:
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Structural and mechanistic studies of catalysts
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Synthesis and characterisation of tetracyc1ic guanidinium phase transfer catalysts I
and 11 from ethyl (R)-3-hydroxybutyrate was undertaken as well as the determnination of their
pKa's to provide insight into the mechanism of their use in phase transfer catalysis. Their
proficiency at catalysing the Michael addition of 2-hydroxy-l ,4-napth~guinone III to trans-~nitrostyrene
IV was studied. Catalyst 11 showing improved reaction times and e.e.' s over I.
The synthesis oftetracyc1ic guanidinium salt V was also attempted unsuccessfully,
Synthesis of copper (1) hydride (CuH.X, X = H20 and pyridine) from three different
routes (Wurtz Reaction [1], NaBH4 reduction [2] LiAIH4 reduction in pyridine [3]) and their
subsequent investigation by inelastic neutron scattering (INS) techniques (neutron
diffraction/spectroscopy) and X-Ray diffraction (XRD) provided insight into the structure of
the copper hydride core and also the nature of the stabilising surface shell (H20 and pyridine
respectively). Direct synthesis of Stryker's reagent [HCU{P(C6H5)3}]6 from copper (ll)
acetate (Cu(OAc)2) and also its deuterium analogues [DCu{P(C6H5)3}]6 and
[HCu{P(C6D5)3}]6 were achieved and the location of their hydride ligands using INS
(SANDALS - neutron diffraction) was detennined.
; Synthesis of organometallic his-(n2 -π-allyl)M (M = Ni VI & Pd VII) cross-coupling
catalysts from the Grignard reaction of metal halides and preparation of active Ni-terpyridyl
complexes (general formula LNih, L = TPY) VIII - XI from the reaction of Ni(CODh and h
with the starting material TPY's was achieved and vibrational INS spectra (TOSCA - neutron
spectroscopy) was used to investigate the low energy vibrations which are linked to catalytic
activity. Similar studies were performed on the commercially available Pd stabilised NHC
PEPPSl pre-catalysts (IPr XII and IMes XIII)).
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