Nitroaldol Reaction in Aqueous Media: An Important Improvement of the Henry Reaction
Roberto Ballini* and Giovanna Bosica
*Dipartimento di Scienze Chimiche dell'Università, Via S. Agostino n. 1,
62032 Camerino, Italy, Email: roberto.ballini
unicam.it
R. Ballini, G. Bosica, J. Org. Chem., 1997, 62, 425-427.
DOI: 10.1021/jo961201h
Abstract
The Henry reaction can be performed under very mild reaction conditions in 0.025 M NaOH in the presence of cetyltrimethylammonium chloride as cationic surfactant. Short reaction times are required and both primary and secondary nitroalkanes give good results.
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Details
The document discusses an improvement in the Henry reaction, a classical carbon-carbon bond-forming process, by performing the nitroaldol reaction in aqueous media. Traditionally, this reaction is conducted in organic solvents with a base, which can lead to side reactions and requires careful control of the reaction conditions. The new method uses water as the reaction medium, which is less toxic, environmentally friendly, and cost-effective. The reaction is carried out using a stoichiometric amount of nitroalkane and aldehyde in a 0.025 M NaOH solution with cetyltrimethylammonium chloride (CTACl) as a surfactant. This approach yields good to excellent results, especially with aliphatic aldehydes, and requires shorter reaction times (2-6 hours). The method is advantageous as it avoids side reactions, preserves various functional groups, and is suitable for large-scale preparations. The procedure is simpler, does not require a large excess of nitroalkane, and operates under mild conditions, making it more efficient and environmentally sustainable compared to conventional methods. The document also provides detailed experimental procedures and characterizations of the products obtained.
Key Words
Henry Reaktion, Henry Nitroaldol Reaction, Nitro compounds
ID: J42-Y1997-160
