The enantioselective organocatalytic Michael addition in aqueous solution was compared with the reaction performed under solvent‐free ball‐milling conditions. A range of pyrrolidine‐derived organocatalysts were tested in the addition of aldehydes to nitroalkenes. Both procedures afforded good yields, diastereoselectivities, and enantioselectivities. The best catalyst in aqueous media was O‐lauroyl‐trans‐4‐hydroxyproline, whilst the ball‐milling technique was most‐efficient with α,α‐diphenyl‐2‐pyrrolidinemethanol trimethylsilyl ether.

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