Microphotochemistry: 4,4'-Dimethoxybenzophenone mediated photodecarboxylation reactions involving phthalimides

Abstract

SummaryA series of 4,4'-dimethoxybenzophenone mediated intra- and intermolecular photodecarboxylation reactions involving phthalimides have been examined under microflow conditions. Conversion rates, isolated yields and chemoselectivities were compared to analogous reactions in a batch photoreactor. In all cases investigated, the microreactions gave superior results thus proving the superiority of microphotochemistry over conventional technologies.

Photodecarboxylations in an Advanced Meso‐Scale Continuous‐Flow Photoreactor

“…Of these, photodecarboxylation reactions of phthalimides have been intensively studied 29, 36. These versatile transformations have also been used as model reactions for meso‐scale production using an advanced circulating falling‐film batch reactor 37, 38, and for continuous‐flow synthesis utilizing improvised microreactor systems 31, 39, 40.…”

Continuous flow reactors: a perspective

“…Shvydkiv, Nolan and Oelgemöller, 55 Compared to conventional cylindrical Schlenk apparatus, the authors calculated that the irradiated area of the micro reactor was 5 to 8 times larger than a 50-100 ml batch vessel and demonstrated larger energy efficiencies. Furthermore, decomposition processes were also avoided through the use of a flow reactor as 'over-irradiation' could be minimised.…”

Flow photochemistry: Old light through new windows

“…Although this is desirable from a technical point of view, particularly with regard to the use of LED light sources, it does introduce further purification issues. The reactions shown in Scheme 16 were performed in both microflow and batch reactors, and although the microflow reactor was seen, in some circumstances, to be more selective for the desired reaction versus reduction, the productivity of the batch reactor was consistently superior [64]. …”