Abstract
The combination of heterogeneous catalysis and biocatalysis into one-pot reaction cascades is a potential approach to integrate enzymatic transformations into existing chemical infrastructure. Peroxygenases, which can achieve clean C-H activation, are ideal candidates for incorporation into such tandem systems, however a constant supply of low-level hydrogen peroxide (H2O2) is required. The use of such enzymes at industrial scale will likely necessitate thein situgeneration of the oxidant from cheap and widely available reactants. We show that combing heterogeneous catalysts (AuxPdy/TiO2) to produce H2O2in situfrom H2and air, in the presence of an evolved unspecific peroxygenase fromAgrocybe aegerita(PaDa-I variant) yields a highly active cascade process capable of oxidizing alkyl and alkenyl substrates. In addition, the tandem process operates under mild reaction conditions and utilizes water as the only solvent. When alkenes such as styrene are subjected to this tandem oxidation process, divergent reaction pathways are observed due to the competing hydrogenation of the alkene by palladium rich nanoparticles in the presence of H2. Each pathway presents opportunities for value added products. Product selectivity was highly sensitive to the rate of reduction compared to hydrogen peroxide delivery. Here we show that some control over product selectivity may be exerted by careful selection of nanoparticle composition.
Original language | English |
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Pages (from-to) | 4170-4180 |
Number of pages | 11 |
Journal | Green Chemistry |
Volume | 23 |
Issue number | 11 |
Early online date | 7 May 2021 |
DOIs | |
Publication status | Published - 7 Jun 2021 |
Bibliographical note
Funding Information:SJF acknowledges the award of a Prize Research Fellowship from the University of Bath and a RSC Research Mobility Grant (RM1802-7768). Financial support from the University of Cape Town and Department of Science and Technology/National Research Foundation Centre of Excellence in Catalysis (C*Change) is also gratefully acknowledged (DW). Further funding and support through the DST-NRF SARChI chair in Bioprocess Engineering (UID 64788), held by STLH, is gratefully acknowledged.
ASJC Scopus subject areas
- Environmental Chemistry
- Pollution