Table 1. 4-OT(F50A)-Catalyzed Nitromethane Addition to α,β-Unstaturated Aldehydes 2a–2k Using Optimized Reaction Conditions^a.

^aAll the reactions were performed in buffer [20 mM HEPES/5% (v/v) ethanol] at pH 6.5 with 4-OT F50A (72 μM, except for 2g and 2i for which 36 μM enzyme was used), 1 (25 mM) and 2a–k (3 mM, except for 2g which was used at 2 mM).

^bDetermined by ¹H NMR analysis.

^cIsolated yield (%).

^dDetermined by chiral HPLC or GC.

^eThe absolute configuration was determined by comparison of chiral HPLC or GC data with those previously reported (see Supporting Information for details).

^fApparent kinetic parameters determined with this substrate at a fixed nitromethane concentration of 25 mM: k_cat = 0.05 (±0.002) s^–1; K_m = 367 (±37) μM.

^gFurther purified using flash column chromatography.