Selective Oxyfunctionalisation Reactions Driven by Sulfite Oxidase‐Catalysed In Situ Generation of H₂O₂

Abstract

H2O2 can be accepted by several peroxygenases as a clean oxidant, able to supply both the necessary electrons and oxygen atom at the same time. The biocatalysts, in turn, are able to catalyse an array of interesting oxygen insertion reactions at enantio‐ and regio‐selectivities hard to attain with classical chemical methods. The sensitivity of most peroxygenases towards H2O2, however, requires this oxidant to be generated in situ. Here, we suggest the application of (modified) sulfite oxidases to couple the oxidation of sulfites to the reduction of oxygen. This enables us to use calcium sulfite, an industrial waste product from scrubbing flue gases, as an electron donor to reduce oxygen. This will supply the required peroxide in a controlled manner and enables us to perform these challenging reactions at the expense of simple salts.

Evolved Peroxygenase–Aryl Alcohol Oxidase Fusions for Self-Sufficient Oxyfunctionalization Reactions

“…the reaction conditions (see the Materials and Methods section for details), Figure 4B. To the best of our knowledge, this value is the highest TTN ever reported for the enzymatic synthesis of dextrorphan, followed far behind by the recently described sulfite oxidase-peroxygenase cascade system 9 with a TTN of 10,540 (i.e., 4-fold less than the current chimeric fusion system). This difference is even more dramatic when compared to the performance of the UPO mutant without the H 2 O 2 cascade, which only achieved 7500 TTN.…”

“…31 Dextrorphan synthesis was determined using a Shimadzu GC-2010 Plus gas chromatograph with an AOC-20i Auto injector with an FID detector (Shimadzu, Japan) using nitrogen as the carrier gas with a previously described method. 9 The reactions were performed in GC vials of 1.5 mL in a final volume of 0.3 mL. For the evaluation of the performance of different alcohols within the cascade, the reactions contained 10 mM of each primary alcohol (2a−f), 0.04 μM of H (peroxygenase concentration measured with the CO difference spectrum) and 10 mM of dextromethorphan hydrobromide in 100 mM potassium phosphate buffer at pH 7.0 were carried out.…”

Enzymatic strategies for asymmetric synthesis

“…Finally, the heme center is poorly compatible with the oxidant; this problem however can be partly circumvented by in situ H 2 O 2 production strategy. 194 …”

Controlling product selectivity with nanoparticle composition in tandem chemo-biocatalytic styrene oxidation

“…In order to circumvent this deactivation, a number of H 2 O 2 delivery methods to UPOs have been reported. These include the use of enzyme cascades (glucose oxidase/peroxygenase 17,18 and formate oxidase/peroxygenase systems 19,20 ) oxidase and peroxygenase fusions, 21 and a number of heterogeneous chemo-and photocatalysts. [22][23][24][25] Among heterogenous catalysts, Au x Pd y bimetallic nanoparticles on various supports have been reported as highly active catalysts for H 2 O 2 direct synthesis.…”