CERC3-Sustainability - Alphand-Fraaije-Mihovilovic-Ottolina: Asymmetric oxidations using two-in-one 2nd generation biocatalysts

Asymmetric oxygenation reactions such as Baeyer-Villiger reactions (BV) are still difficult to achieve by chemical means, while this type of reaction can lead to highly valuable chemicals. Therefore, Baeyer-Villigerases represent highly attractive alternatives as these biocatalysts are able to catalyse a large variety of oxidation reactions (notably BV oxidations and sulfoxidations) while exhibiting a remarkable selectivity. Exploitation of these biocatalysts would afford effective environment-friendly synthesis routes ("green chemistry") possessing several advantages over chemical routes. This includes the renewability of the catalyst, reduced formation of by-products thanks to fewer side reactions, and the possibility to use mild process conditions. However, the small number of available monooxygenases, more particularly BVases, as well as their NAD(P)H cofactor dependence are a substantial limitation to their development for asymmetric synthesis and industrial processes. This project is aimed at solving these problems by: i) preparing two-in-one "2nd generation" biocatalysts integrating the oxidative enzyme and an internal cofactor recycling system in order to improve and simplify whole cell as well as enzymatic based processes ii) offering a toolbox of various recombinant biocatalysts with a large range of selectivity and complementary substrate acceptance profiles iii) optimizing biotransformation processes in terms of yield (i.e. dynamic resolution using simultaneously chemical racemising agents and biocatalysts), usable concentration (i.e. extractive catalysis to overcome inhibition problems), simplification of work up step (i.e. in situ product removal techniques, immobilised biocatalyst). This envisaged approach will combine expertise in biochemical engineering, organic chemistry and industrial biocatalysis. This multidisciplinary strategy will not only yield new applicable biocatalytic tools but will also result in a range of technical and scientific novelties.

Asymmetric oxygenation reactions such as Baeyer-Villiger reactions (BV) are still difficult to achieve by chemical means, while this type of reaction can lead to highly valuable chemicals. Therefore, Baeyer-Villigerases represent highly attractive alternatives as these biocatalysts are able to catalyse a large variety of oxidation reactions (notably BV oxidations and sulfoxidations) while exhibiting a remarkable selectivity. Exploitation of these biocatalysts would afford effective environment-friendly synthesis routes ("green chemistry") possessing several advantages over chemical routes. This includes the renewability of the catalyst, reduced formation of by-products thanks to fewer side reactions, and the possibility to use mild process conditions. However, the small number of available monooxygenases, more particularly BVases, as well as their NAD(P)H cofactor dependence are a substantial limitation to their development for asymmetric synthesis and industrial processes. This project is aimed at solving these problems by: 1. preparing two-in-one "2nd generation" biocatalysts integrating the oxidative enzyme and an internal cofactor recycling system in order to improve and simplify whole cell as well as enzymatic based processes 2. offering a toolbox of various recombinant biocatalysts with a large range of selectivity and complementary substrate acceptance profiles 3. optimizing biotransformation processes in terms of yield (i.e. dynamic resolution using simultaneously chemical racemising agents and biocatalysts), usable concentration (i.e. extractive catalysis to overcome inhibition problems), simplification of work up step (i.e. in situ product removal techniques, immobilised biocatalyst). This envisaged approach will combine expertise in biochemical engineering, organic chemistry and industrial biocatalysis. This multidisciplinary strategy will not only yield new applicable biocatalytic tools but will also result in a range of technical and scientific novelties.