Imidazole-Catalyzed Henry Reactions in Aqueous Medium

2-Nitroalkanols can be efficiently synthesized using imidazole as a mild Lewis basic catalyst in aqueous medium as well as in organic solvents. The products have been found in good yields without purification (> 95% purity by ¹H NMR) for aromatic aldehydes. Additionally, the very mild reaction conditions prevent the particular side reactions such as aldol condensation, Cannizzaro reaction, or dehydration of the 2-nitro alcohols into nitro alkenes even if aromatic aldehydes are used. This report satisfies the criteria for green synthesis in terms of reaction medium and recycling of the catalyst (imidazole).