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

4
Chapter One
ortho-biphenyl triflates, heterocyclic triflates and more importantly complex aryl triflates
derived from fluorescein (2) and quinine (3), demonstrating that the method could be
applied to the synthesis of pharmaceutically important compounds to afford the desired
fluorinated products in good yields (57-84 %).
Scheme 1.4 Fluorination of aryl triflates
Figure 1.3 Structures of products derived from fluorescein (2) and quinine (3)
The nucleophilic and electrophilic fluorinating reagents described previously, though useful,
are unable to fluorinate compounds in an enantioselective manner without the addition of a
chiral catalyst. Subsequently, the development of fluorinating agents with inbuilt chirality
has received considerable attention in the literature.
1.2 Chiral Electrophilic Fluorinating Reagents
The first enantioselective fluorination reaction was carried out in 1988 by Differding and
Lang, [18] who synthesised N-fluoro sultams (4) and (5), the first examples of
enantioselective fluorinating reagents (Scheme 1.5).