Synthesis and Comparison of the Reactivity of Allyl Fluorides and ...

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Chapter Four
were both reacted with sodium dimethyl malonate affording the same product, therefore, the
Pd �-allyl complexes were subsequently synthesised from the allylic chloride. It was
observed that in reaction with sodium dimethyl malonate the substituent on the benzene had
an effect on the outcome of nucleophilic attack, when R = para-CF3, the less hindered
carbon was attacked, however, when R = meta-F, attack occurred at the more hindered
carbon atom. Pd cationic complexes were also reacted with sodium 1-fluoro
bis(phenylsulfonyl)methane (140), affording the desired novel product (155) in addition to
the novel co-product allyl 1-fluoro bis(phenylsulfonyl)methane (156), forming as a result of
excess sodium 1-fluoro-bis (phenylsulfonyl)methane reacting with the allyl fragment from
the [{Pd(C3H5)Cl}2] starting material. Finally, the reaction of (135) with TBAF, TASF,
HF.pyridine, TREAT HF and NaF was investigated (Scheme 4.15). The reactions were
monitored by 1 H and 19 F NMR spectroscopy, however, formation of the desired allylic
fluoride was not observed, under the reaction conditions employed. Therefore, further work
is still required to fully examine this reaction. In chapter five, a novel library of analogous
allylic difluorides will be synthesised and their reactions with Pd(0) investigated.
Scheme 4.15 Attempted synthesis of allylic fluorides