Despite the growth of photoredox
methods in academia, application
of photoredox at scale in the pharmaceutical and fine chemical industries
has been slow. In this report, a photoredox trifluoromethylation of
a thiophenol was modified from the original literature report, and
the mechanism was investigated to define the key scale-up parameters.
The mechanistic insight was leveraged in the design and execution
of two different reactor designs: an LED-based plug flow photoreactor
and a laser-based continuous stirred tank photoreactor. In one of
the first examples of commercial-scale photoredox chemistry, the process
was scaled to provide over 500 kg of the desired intermediate and
amended to fully continuous manufacturing.