Atropoisomeric quinolinium salt promoting the access to both enantiomeric forms of methyl mandelate: a versatile NADH mimicElectronic supplementary information (ESI) available: experimental. See http://www.rsc.org/suppdata/cc/b2/b207434f/

Asymmetric reduction of methyl benzoylformate by a new NADH mimic is reported; depending on the hydride source used to reduce the NAD+ precursor, NADH mimics so obtained lead to an inversion of enantioselectivity, affording either (R)-methyl mandelate in 88% ee or (S)-methyl mandelate in 78% ee.