Asymmetric reduction with 5-deazaflavin. III. Reduction of ethyl benzoylformate in the presence of chiral ligand

Article abstract of DOI:10.1248/cpb.38.616

A nonenzymatic asymmetric reduction of ethyl benzoylformate with an achiral 1,5-dihydro-5-deazaflavin derivative in chiral media was investigated as a model system for reduced nicotinamide adenine dinucleotide (phosphate)-dependent dihydrogenase. The chiral media include chiral nuclear magnetic resonance shift reagent, chiral Lewis acid, and a combination of metal ion and chiral ligand (additive). Of these reductions, a substantial asymmetric induction was observed in the presence of tris-[3-(heptafluoropropylhydroxymethylene)(+)-camphorato]europium to give ethyl mandelate possessing predominantly S-configuration, in an optical yield of 24 to 36%. These values are among the highest so far reported in nonenzymatic reduction of ethyl benzoylformate with a 5-deazaflavin model. The discrimination of the prochiral face of the carbonyl compound was effective even when a catalytic amount of the chiral shift reagent was employed.

Full text of DOI:10.1248/cpb.38.616

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