One-Pot Enzymatic-Chemical Cascade Route for Synthesizing Aromatic α-Hydroxy Ketones

2-Hydroxyacetophenone (2-HAP) is an important building block for the production of a series of natural products and pharmaceuticals; however, there is no safe, efficient, and economical method for 2-HAP synthesis. Here, a one-pot enzymatic-chemical cascade route was designed for synthesizing 2-HAP based on retrosynthetic analysis. First, a spontaneous proton-transfer reaction was designed using a computational simulation that enabled 2-HAP synthesis from the isomer 2-hydroxy-2-phenylacetaldehyde. A route for 2-hydroxy-2-phenylacetaldehyde synthesis was then constructed by introducing the unnatural substrate glyoxylic acid into a C-C ligation reaction catalyzed by Candida tropicalis pyruvate decarboxylase. Assembly and optimization of this enzymatic-chemical cascade route resulted in a final yield of 92.7%. Furthermore, stereospecific carbonyl reductases were introduced to construct a synthetic application platform that enabled further transformation of 2-HAP into (S)- and (R)-1-phenyl-1,2-ethanediol. This method of cascading spontaneous chemical and enzymatic reactions to synthesize chemicals offers insight into avenues for synthesizing other valuable chemicals.

Automated summary

A one-pot enzymatic-chemical cascade route was developed to synthesize 2-Hydroxyacetophenone (2-HAP) with a final yield of 92.7%. The introduction of stereospecific carbonyl reductases allowed for further transformation of 2-HAP into (S)- and (R)-1-phenyl-1,2-ethanediol. This method shows potential for synthesizing other valuable chemicals by cascading spontaneous chemical and enzymatic reactions.