The development of P450 platform technology has enabled the sustainable production of an oxygenated intermediate, 4-hydroxy-α-isophorone, on kilogram scale. Application of a cytochrome P450 enzyme resulted in an unprecedented product concentration of 10 g/L and a space–time yield of 1.5 g/L/h. These findings are highly relevant for the economical evaluation of cytochrome P450 technology and, additionally, provide access to an alternative and cost-effective route toward 4-hydroxy-α-isophorone.

Screening of 60 transaminases using three different amine donors found that the ω-transaminase from Vibrio fluvialis together with (S)-α-methylbenzylamine to be the most promising combination to deliver the desired (S)-1-(5-fluoropyrimidin-2-yl)-ethylamine (2) in almost quantitative conversion. The process was further improved by the addition of immiscible organic solvents with toluene identified as most suitable concerning the distribution of the reactants without negatively impacting the performance of the biocatalyst. Further process optimization using commercial enzyme preparations of V. fluvialis led to product/catalyst ratios of 15 g/g cell dry weight. This approach led to a process that provided (S)-1-(5-fluoropyrimidin-2-yl)ethylamine (2) in 77% yield with 99.8% ee. In addition, a recombinant E. coli-based whole-cell biocatalyst was also designed and applied to this process. The use of this low cost enzyme formulation gave product of similar quality to that obtained using the commercial formulation of V. fluvialis . This process was further optimized and scaled-up to deliver (S)-1-(5-fluoropyrimidin-2-yl)ethylamine (2)with a yield of 66% and an optical purity of 97.3% ee. These results confirm the efficiency and competitiveness of the transaminase technology for the production of chiral amines.

Alcohol dehydrogenases (ADH) are widely used to enantioselectively reduce ketones to chiral alcohols, but their application in industrial scale oxidations is rare. Reasons are the need for an NAD(P)+ cofactor regeneration system, often low performance in oxidative reactions and the limited substrate scope of ADHs. ADHA from Candida magnoliae DSMZ 70638 is identified to efficiently catalyze the regio‐selective hydroxy‐lactone oxidations to hydroxy‐lactones. Hydroxy‐lactones are common intermediates in industrial processes to cholesterol lowering (va)statin drugs. A biocatalytic aliphatic hydroxy‐lactone oxidation process is developed using pure oxygen as oxidant reaching volumetric productivities of up to 12 g L−1 h−1, product concentrations of almost 50 g L−1 and 95% reaction yield. For co‐factor recycling a previously engineered, water‐forming NAD(P)H‐oxidase from Streptococcus mutans is used. The process is scaled up to industrial pilot plant scale and it could be demonstrated that ADH catalyzed oxidations can be developed to efficient and safe processes. However, the ADHA wild‐type enzyme is not productive enough in chlorolactol oxidation. Therefore, enzyme engineering and multi‐parameter screening is successfully applied to optimize the enzyme for the target reaction. The optimized ADHA variant shows a 17‐fold higher oxidative activity, a 26°C increased stability and is applied to develop an efficient chlorolactol oxidation process.

High throughput screening was used to find a cost-effective and scalable catalyst for the asymmetric hydrogenation of a sterically demanding enamide as an intermediate towards a new potent melanocortin receptor agonist useful in the treatment of obesity. Lessons drawn from the testing of a first library of 96 chiral monodentate phosphoramidites led to the design of a second focused library of 16 chiral ligands, allowing the discovery of a new efficient catalyst. This catalyst was based on rhodium and a bulky monodentate phosphite ligand. The catalyst was scaled up and used in the kilogram production of the desired bulky chiral amide.

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