Photobiocatalysis is currently in vogue. The number of reports combining the disciplines of biocatalysis and photocatalysis is rapidly increasing. While the synthetic possibilities enabled by photobiocatalysis are fascinating, the economic feasibility and environmental impact are largely neglected in the current literature. In this contribution, we present a range of key indicators for economic feasibility and environmental impact that may be useful for readers to assess their own work and thereby avoid unrealistic exaggerations. We also critically review the current state of the art in photobiocatalysis and question its synthetic practicability beyond the laboratory. With this contribution, we aim to provoke an open discussion.@en

This study explores a chemoenzymatic cascade to synthesise chiral β-hydroxy ketones by integrating the selective oxyfunctionalisation capabilities of peroxygenases with the carbon-carbon bond-forming progress of organocatalysts. Initial results with simple organocatalysts demonstrated poor performance due to mutual inactivation of the biocatalyst and organocatalyst. However, the use of more complex prolinamide derivatives improved the reaction efficiency and enantioselectivity, enabling a one-pot, one-step synthesis process. This methodology was further optimised to produce high yields of enantiomerically pure aldol products and was shown to be extendable to other substituted toluenes and aldol donors.@en

Biocatalytic oxidation reactions of toluene derivates to the corresponding aldehydes are typically challenged by regio- and chemoselectivity issues. In this contribution we address both challenges by a combined reactant- and reaction engineering approach. We demonstrate that the peroxygenase-catalysed transformation of ring-substituted toluenes proceeds highly regioselectively in benzylic position. Furthermore, neat reaction conditions not only enable attractive product concentrations (up to 185 mM) but also result in highly chemoselective oxidations to the aldehyde level.

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