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Volume 34: Fluorine |
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Introduction by Prof. Jonathan Percy (Volume Editor): |
| The chemical and patent literature contains very many monofluorinated compounds;
most of them fall outside the scope of this volume because they contain fluorine bound
to an aromatic or heteroaromatic nucleus. In these locations, a single fluorine atom can
increase bioavailability by increasing hydrophobicity, or block metabolic oxidation; these
effects are familiar and much exploited. In the molecules described in this volume, the
solitary fluorine atom can modify pKa (and bioavailability), conformation, molecular recognition
(through the modulation of hydrogen bonding networks), and serve as a valuable
label for NMR studies in vivo and in vitro, and all with minimal perturbation of molecular
volume. |
| The synthetic chemistry described in this volume achieves
the exchange of many of the most common functional groups for a single C¾F bond. Some of the reagents required are relatively hazardous and require careful handling; others
are considerably more amenable to general use. |
| The volume covers the entire landscape of reagents from elemental fluorine and hydrofluoric
acid, to transition-metal catalysts which mediate the introduction of fluorine
in novel ways. The chemistry often occurs close to, or at, mechanistic borderlines; there is
little real physical organic understanding of any of the transformations described in this
volume so reaction outcomes can be unpredictable. |
| Much of the primary and review literature upon which this volume is based deals
with methodology rather than types of target molecules. The organofluorine literature
contains relatively few comparisons between methods, which can make route selection
rather difficult. Where the literature is sufficiently extensive, individual contributors
have been encouraged to compare and contrast the scope and effectiveness of the available
methodologies. These comparisons, and the organization of the volume into target
classes and types of functional group exchange reaction, will assist experimentalists in
planning synthetic campaigns. |
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