Methods for Organic Electrosynthesis - Fundamentals and Applications of Organic Electrochemistry - page 65

factors, such as electrode materials, applied
potential, current density, electrolytic solvents,
supporting electrolytes, electric field,
adsorption orientation of substrate or
intermediate species at the electrode surface
and so on [4-7]. Heterogeneous electrolytic
reactions therefore often exhibit different
selectivity from ordinary homogeneous
chemical reactions. In particular, when an
electrochemically generated reactive species or
intermediate reacts with reagents before it
diffuses from the electrode into the solution,
the stereo- and regioselectivities of the product
are often quite different from those of ordinary
chemical reactions. Typical examples of the
selectivity of electrode reactions are described
in the following sections.
4.3.2.1 Chemoselectivity
Chemoselectivity in ordinary chemical reactions
is controlled by the choice of reagents, but it is
quite difficult to achieve high chemoselectivity
when multiple similar functional groups exist in
a single molecule. On the other hand,
chemoselectivity can be achieved by the control
of applied potential based on the difference
between the redox potentials of functional
groups. Since the applied potential is adjusted
precisely using a potentiostat, high selectivity
can be readily achieved. For instance, even
though phenylimino and alkylimino groups
exist in the same molecule, as shown in Eq. 4.6 ,