Heterocycle formation from 1,3-dinitroalkanes. A novel pyrazole synthesis

Supramolecular Columnar Liquid Crystals with Tapered‐Shape Simple Pyrazoles Obtained by Efficient Henry/Michael Reactions

“…As uccessful route was identified and this involved the preparation of 3,5-dimethyl-4-aryl-1H-pyrazoles from 1,3-dinitroalkanes, [15] whichcan be obtainedfrom readily accessible benzaldehydes by efficient Henry/Michael reactions. This synthetic route, along with the chemical structureso ft he resultingp yrazoles 4a-f,i sd epicted in Scheme 1.…”

“…[15] As ide reactionr elated to that in which the 2-aryl-1,3-dinitro compounds can be readily transformed under basic conditions into 2-isoxazoline-2-oxides or isoxazoles has been reported. [18,19] In our case, the formation of the 3,5-dimethyl-4-arylisoxazole byproduct was also observeda nd this was minimized by adding acetic acid.…”

Deep eutectic solvent as solvent and catalyst: one-pot synthesis of 1,3-dinitropropanesviatandem Henry reaction/Michael addition

“…Reduction of the nitro moiety produces 1,3 diamines, important structural motifs existing in many natural products and pharmaceuticals. 23 They are precursors of different targets such as heterocycles, 24 benzene derivatives, 25 carbohydrates, 26 and cyclohexane derivatives. 27 They have been also used as key building blocks for biologically active substances including a novel oxazolidinone antibacterial candidate.…”

Recent advances in asymmetric organocatalysis mediated by bifunctional amine–thioureas bearing multiple hydrogen-bonding donors

“…The obtained adducts with two adjacent stereogenic centers could be easily transformed into optically active 1,3-diamines, which are of great significance and synthetic value. 18 In sharp contrast to employing carbonyl substrates with electron-withdrawing groups such as CO 2 R, NO 2 , or CN at the a-position as nucleophiles, a-aryl substituted carbonyl compounds have rarely been used as the nucleophile in asymmetric reaction (Scheme 10). To our knowledge, only one example of the racemic version using a-aryl cyclopentanones as the nucleophile and nitroolefin as the electrophile had been reported before our investigation of the asymmetric version.…”