Organic Electrosynthesis - Fundamentals and Applications of Organic Electrochemistry - page 256

Figure 6.28 Schematic representation of a
microflow electrochemical reactor
Atobe and co-workers reported that the use of
parallel laminar flow in a microflow
electrochemical reactor enables the effective
generation of an N -acyliminium ion followed by
trapping with an easily oxidizable carbon
nucleophile such as allyltrimethylsilane ( Figure
6.29 ) [77]. A solution of a cation precursor and
a solution of allyltrimethylsilane are introduced
in a parallel manner. The laminar flow prevents
the oxidation of allyltrimethylsilane at the
anode. Only the precursor is oxidized to
generate the N -acyliminium ion. The
N -acyliminium ion that is generated diffuses
and reacts with allyltrimethylsilane. Although
the efficiency of the process is very low for the
Bu 4 NBF 4 /CH 3 CN system, use of the
Bu 4 NBF 4 /TFE (2,2,2-trifluoroethanol) system
(59% yield) or an ionic liquid (62-91% yield)
gave rise to the formation of the desired
product.