What exactly does fluorination of some compound do in a biological sense?
I read the following things about what fluorine does for drugs:
- Fluorine withdraws electron density and can make an acid stronger.
- Fluorine substitution can increase lipophilicity - I don't understand this. Lipids are non-polar; I can't see why adding fluorine would generally decrease the polarity of some molecule ...
- Carbon-fluorine bonds are exceptionally stable and resist change.
However, can anyone provide some concrete examples of fluorine influencing the behavior of some drug? I could only find very general points on the internet.