Nitroalkenes acetylacetone

Under optimized conditions, the 83-catalyzed (1 mol% loading) Michael addition of acetylacetone to various aryl nitroalkenes as well as alkyl nitroalkenes proceeded in good to excellent yields (80-97%) and enantioselechvities (82-99%) of the desired adducts 1-5 (Scheme 6.93). The authors also reported the successful enantioselective Michael addihon of l,3-diphenylpropane-l,3-dione (adduct in... 

Scheme 6.93 Typical products of the asymmetric Michael addition of acetylacetone to various nitroalkenes catalyzed by 83.

The use of nitroalkenes in the formation of the furan ring has been refined and used in the preparation of a number of furanoterpenoids (80JOC2945). The furan (94) is obtained by the action of nitrotrichloroethylene on acetylacetone in the presence of base (77ZOR972). A new synthesis of acetylfurans is illustrated by the preparation of the 2-acetylfuran (95) from acetylacetone and 2-nitropropene in the presence of potassium fluoride (78JCS(Pl)l 144). 

Acetylacetone has also been the subject of several studies when used as 1,3-dicarbonyl compound suitable to engage in a Michael reaction with nitroalkenes under H-bonding catalysis. In this context, Takemoto s catalyst 68a and valine-derived thiourea 74 have been tested in the reaction with acetylacetone with nitrostyrene furnishing good results, although no extensive study was carried out in order to evaluate the substrate scope with regard to the substitution at the nitroalkene. On the other hand, several functionalized thioureas have been expressly surveyed in this reaction, providing a detailed study... 

Scheme 4.10 Enantioselective Michael addition of acetylacetone to nitroalkenes catalyzed by multifunctional thioureas.

Scheme 1.55 Michael additions of acetylacetone to nitroalkenes catalysed by bifunctional amine-thioureas.

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