# Biocatalysis Under Reduced Pressure; Two‐Step, One‐Pot Amide Synthesis Using an Immobilised Transaminase/Lipase Cascade in Combination With By‐Product Removal

## TL;DR

Scientists developed a new method using enzymes to make amides efficiently by removing by-products under reduced pressure.

## Contribution

A novel two-step, one-pot biocatalytic cascade using immobilized enzymes and by-product removal under reduced pressure is introduced.

## Key findings

- An immobilized lipase catalyzed a kinetic resolution of a chiral amine with high enantiopurity.
- A transaminase/lipase cascade achieved amide synthesis with >99% enantiomeric excess and high yield.
- The method uses standard lab equipment and addresses enzyme incompatibility challenges.

## Abstract

Immobilisation of biocatalysts has expanded their applicability under non‐conventional conditions, particularly for compatibility in synthetic processes by improving stability in non‐aqueous media and enabling reusability. The combination of biocatalysts in cascade reactions is often a useful strategy with significant advantages. However, the utility of cascades can be hindered by incompatibilities between enzymes and/or substrates and long reaction times. Herein, we describe the innovative use of a rotary evaporator for performing lipase‐catalysed reactions under reduced pressure, facilitating the in situ evaporation of a volatile by‐product and shifting the reaction equilibrium towards the desired product(s). This is demonstrated with an immobilised lipase‐catalysed kinetic resolution of a chiral amine that yields products of high enantiopurity. Additionally, a two‐step, one‐pot biocatalytic cascade is developed by coupling the lipase with an immobilised, pyridoxal 5′‐phosphate (PLP)‐dependent transaminase (ATA). To address the challenges of combining these biocatalysts, we optimised the immobilisation support, solvent (organic/aqueous) and water content. Together, the enantioselective ATA/lipase cascade converts a prochiral ketone substrate to an amide with high yield and > 99% enantiomeric excess (%ee). This methodology demonstrates that biocatalysts can be readily combined for organic synthesis with standard laboratory apparatus and encourages a similar approach to be applied to other reactions.

The application of biocatalytic cascades for organic synthesis can be encouraged through the use of easy‐to‐handle, immobilised enzymes and common laboratory equipment. We present a sequential biocatalytic cascade reaction that couples a transaminase (ATA) with a lipase, and achieves high conversion and enantioselectivity through by‐product removal under reduced pressure.© 2026 WILEY‐VCH GmbH