Products Cited in Publications Worldwide One-Pot Sequential Two-Step Photo-Biocatalytic Deracemization of sec-Alcohols Combining Photocatalytic Oxidation and Bioreduction

One-Pot Sequential Two-Step Photo-Biocatalytic Deracemization of sec-Alcohols Combining Photocatalytic Oxidation and Bioreduction

Rudzka, Aleksandra; Antos, Natalia; Reiter, Tamara; Kroutil, Wolfgang; Borowiecki, Pawel

DOI:

Abstract

Chiral are versatile building blocks and are of particular interest in the asym. synthesis of nonracemic active pharmaceutical ingredients, agrochems., fragrances, flavors, natural products, etc. Herein, we report on a "one-pot sequential two-step" concurrent oxidation-reduction photobiocatalytic process to synthesize enantiomerically enriched alcs. In this regard, an efficient photocatalytic system based on irradiation with 440 nm blue LEDs in the presence of as a metal-free photocatalyst and mol. oxygen as the terminal oxidant in dry DMSO as the hydrogen peroxide-neutralizing agent was used to oxidize a broad range of racemic (hetero)benzylic alcs. into prochiral quantitively (>99% conv.). The in situ formed carbonyl compounds were subsequently converted into the corresponding chiral alcs. via a sequential biocatalytic transhydrogenation catalyzed by lyophilized E. coli cells overexpressing highly stereoselective and stereocomplementary recombinant alc. dehydrogenases (ADHs) originated from Rhodococcus ruber (E. coli/ADH-A) or Rhodococcus erythropolis (E. coli/ReADH) to obtain (S)-alcs. and Lactobacillus kefir (E. coli/Lk-ADH) or KRED-110 to obtain (R)-alcs., resp. Overall, the elaborated photobiocatalytic deracemization of racemic alcs. using a 9-fluorenone-O2-blue LED-DMSO-E. coli/ADH system carried out on a semipreparative scale (0.25 mmol; 63 mM final concentrate in 4 mL) at room temperature yielded nonracemic alcs. with 82-99.9% conv., in up to 92% isolated yield, with 97-99.9% ee and complementary chirality.

Keywords

photoredox catalysis ; biocatalysis ; alcoholdehydrogenases ; nonstereoselective oxidation ; asymmetricbioreduction ; one-pot sequential cascades ; chiralalcohols

Purchased from AmBeed

NADPH tetrasodium salt

A3414692646-71-198%

NADPH tetrasodium salt

890.0/5g

Detail