Scheme 1. Enzymatic asymmetric strategies relying on stereoselective reactions: (i) reduction, (ii) C–heteroatom-bond formation and (iii) C–C-bond formation by addition of nucleophilic carbon (4-OT: 4-oxalocrotonate tautomerase, ADH: alcohol dehydrogenase, HNL: hydroxynitrile lyase, IRED: imine reductase, OYE: Old Yellow Enzyme, RedAm: reductive aminase, TA: transaminase, ThDP: thiamine diphosphate, Nu: nucleophile).
