The crude earthworm extract catalysed direct asymmetric aldol reactionsa.

aOptimized reaction conditions: aldehyde (0.50 mmol), ketone (7.50 mmol), the crude earthworm extract (75 mg), deionized water (0.05 mL), and MeCN (0.95 mL) at 25°C.bYield of the isolated product after silica gel chromatography.cDetermined by chiral HPLC analysis performed using Chiralpak AD-H, AS-H, or Chiralcel OD-H column, by comparing the retention time with those of known compounds (For details, please see the Supplementary material).dUn-optimized conditions: 4-cyanobenzaldehyde (0.50 mmol), cyclohexanone (2.50 mmol), the crude earthworm extract (50 mg), deionized water (0.05 mL), and MeCN (0.95 mL) at 30°C.eThe reaction was conducted in the absence of the crude earthworm extract, otherwise under the same conditions as entry 9.fThe crude earthworm extract (50 mg) in deionized water (3 mL) was stirred at 100°C for 24 h, and then water was removed under reduced pressure before use. The reaction was conducted under the same conditions as entry 9.gThe crude earthworm extract (50 mg) in Cu2+ solution (0.25 M) [anhydrous CuSO4 (120 mg) in deionized water (3 mL)] was stirred at 30°C for 24 h, and then water was removed under reduced pressure before use. The reaction was conducted under the same conditions as entry 9.hThe reaction was conducted using anhydrous CuSO4 (120 mg) as a catalyst instead of the crude earthworm extract, otherwise under the same conditions as entry 9.