What question did this study set out to answer?

To improve the scalability of asymmetric alkene reduction using thermostable flavin ene-reductase.

May 16, 2026Open Access

Multigram-Scale Asymmetric Alkene Reduction Catalyzed by a Thermostable Flavin Ene-Reductase

Key Points

To improve the scalability of asymmetric alkene reduction using thermostable flavin ene-reductase.
Performed multigram-scale reactions with 0.2 wt % thermostable OYE from Thermus scotoductus.
Conducted the reaction at concentrations of 150 g/L using (S)-carvone.
Assessed turnover numbers, isolated yield, and enantiomeric excess.
Achieved a turnover number of 123,000 with (S)-carvone.
Obtained 90% isolated yield of (2R,5S)-dihydrocarvone with >99% enantiomeric excess.
Maintained an environmental E-factor of 11.6.

Abstract

Chiral-substituted carbonyl compounds can be sustainably obtained via asymmetric alkene reduction catalyzed by ene-reductases from the Old Yellow Enzyme (OYE) family. Yet OYEs are seldom implemented in scale-up reactions due to low turnover numbers (TONs). Herein, we demonstrate multigram 150 g/L scale reactions with the thermostable OYE from Thermus scotoductus (0.2 wt %) for the asymmetric reduction of monoterpenes. Best results were achieved with (S)-carvone (7.5 g), affording a record TON of 123,000, with 90% isolated yield and >99% enantiomeric excess of (2R,5S)-dihydrocarvone, and an environmental E-factor of 11.6.

Multigram-Scale Asymmetric Alkene Reduction Catalyzed by a Thermostable Flavin Ene-Reductase

Key Points

Abstract

Cite This Study