Organic Electrosynthesis - Fundamentals and Applications of Organic Electrochemistry - page 277

developed [118]. For instance, anodic oxidation
of a primary amine generally forms an aldehyde
via an imine intermediate, while the same
oxidation using a TiO 2 catalyst with Pt
deposited on it affords a secondary amine, as
shown in Figure 6.35 [119]. In this case, the
primary amine is oxidized with the hole
generated by photo-excitation to form an
aldehyde, which reacts with the unreacted
starting amine to form an imine intermediate.
The imine is immediately reduced at a Pt site,
resulting in the formation of the secondary
amine. This is due to both oxidation and
reduction occurring at active sites close to each
other. By using this principle, the synthesis of
optically active pipecolinic acid from optically
active lysine was achieved by photocatalytic
reaction using platinized semiconductor TiO 2
powder particles, as shown in Eq. 6.32 [120].
Thus, photocatalytic reactions can be
considered to be wireless electrolytic reactions.
(6.32)