Biocatalysis for the asymmetric synthesis of Active Pharmaceutical Ingredients (APIs): this time is for real

Biocatalysis has emerged as a powerful and useful strategy for the synthesis of active pharmaceutical ingredients (APIs). The outstanding developments in molecular biology techniques allow nowadays the screening, large-scale production, and designing of biocatalysts, adapting them to desired reactions. Many enzymes can perform reactions both in aqueous and non-aqueous media, broadening even further the opportunities to integrate them in complex pharmaceutical multi-step syntheses.This paper showcases several examples of biocatalysis in the pharmaceutical industry, covering examples of different enzymes, such as lipases, oxidoreductases, and transaminases, to deliver active drugs through complex synthetic routes. Examples are critically discussed in terms of reaction conditions, motivation for using an enzyme, and how biocatalysts can be integrated in multi-step syntheses. When possible, biocatalytic routes are benchmarked with chemical reactions.The reported enzymatic examples are performed with high substrate loadings (>100 g L-1) and with excellent selectivity, making them inspiring strategies for present and future industrial applications. The combination of powerful molecular biology techniques with the needs of the pharmaceutical industry can be aligned, creating promising platforms for synthesis under more sustainable conditions.