Lipase/H2SO4-Cocatalyzed Dynamic Kinetic Resolution of Alcohols in Pickering Emulsion

This is the peer reviewed version of the following article: Moon J., Kin T., Mizuno K., et al. Lipase/H2SO4-Cocatalyzed Dynamic Kinetic Resolution of Alcohols in Pickering Emulsion. ChemCatChem 15, e202300878 (2023), which has been published in final form at https://doi.org/10.1002/cctc.202300878. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

This study reports the first chemoenzymatic dynamic kinetic resolution (DKR) of racemic sec-alcohols by simultaneously using immobilized lipase and aqueous sulfuric acid as catalysts for kinetic resolution and racemization, respectively. The nanoparticle-stabilized phase separation in a Pickering emulsion enabled the use of these inherently incompatible catalysts in a single vessel. The racemization reaction in the aqueous sulfuric acid solution significantly suppressed the dehydrative side reactions that form alkenes and dimeric ethers, which are often observed in racemization using Brønsted/Lewis acids or oxovanadium compounds in organic solvents. The efficacy of the Pickering emulsion was confirmed by the significantly lower catalytic performance in DKR without emulsification. This method achieved high yields and high optical purities in the production of a wide range of sec-alcohols.