5437-59-2Relevant academic research and scientific papers
Micelle-enabled palladium catalysis for convenient sp2-sp3 coupling of nitroalkanes with aryl bromides in water under mild conditions
Brals, Jeremy,Smith, Justin D.,Ibrahim, Faisal,Gallou, Fabrice,Handa, Sachin
, p. 7245 - 7250 (2017/11/09)
The efficacy of custom surfactant FI-750-M, designed to mimic polar solvents such as DMF and 1, 4-dioxane, has been demonstrated with the palladium-catalyzed sp2-sp3 coupling of nitroalkanes to aryl bromides using a heteroleptic palladium catalyst under unprecedentedly mild conditions. Optimized reaction conditions mostly provided good yields up to gram scale, with high selectivity and functional group tolerance for a wide scope of aryl bromides. Use of surfactant FI-750-M makes water the gross reaction medium and enables in-flask recycling. The behavior of the surfactant has been elucidated with DLS and cryo-TEM measurements, and mechanistic investigations have revealed the importance of the π-allyl ligand in the catalytic cycle.
Synthesis of 5-alkyl-5-aryl-γ-lactams from 1-aryl-substituted nitroalkanes and methyl acrylate via Michael addition and reductive lactamization
Xu, Jingjing,Li, Xingyao,Wu, Jinlong,Dai, Wei-Min
, p. 3839 - 3846 (2014/06/09)
A general method for accessing 5-alkyl-5-aryl-γ-lactams has been developed using readily available aryl bromides, nitroalkanes, and methyl acrylate as the starting materials. The palladium-catalyzed arylation of nitroalkanes gave the 1-aryl-substituted nitroalkanes, which underwent the DBU-mediated Michael addition with methyl acrylate at room temperature to afford the methyl 4-aryl-4-nitroalkanoates. The latter were then subjected to the nitro reduction using NaBH4-NiCl2·6H2O in MeOH at 0 °C to furnish, after treatment with aqueous K 2CO3 at room temperature, the 5-alkyl-5-aryl-γ- lactams in good to excellent overall yields. Selected examples of N-alkylation of the γ-lactams were also illustrated.
Synthesis of 5-alkyl-5-aryl-1-pyrroline N-oxides from 1-aryl-substituted nitroalkanes and acrolein via Michael addition and nitro reductive cyclization
Xu, Jingjing,Li, Xingyao,Wu, Jinlong,Dai, Wei-Min
, p. 6384 - 6391 (2015/03/30)
A general method for accessing 5-alkyl-5-aryl-1-pyrroline N-oxides (AAPOs) has been established using readily available aryl bromides, nitroalkanes, and acrolein as the starting materials. The palladium-catalyzed arylation of nitroalkanes gave the 1-aryl-substituted nitroalkanes, which underwent the Et3N-catalyzed Michael addition with acrolein at room temperature to afford the 4-aryl-4-nitroaldehydes. The latter were then subjected to the nitro reductive cyclization using Zn-HOAc in EtOH at 0 °C followed by warming the reaction mixture to room temperature for 24 h, furnishing the 5-alkyl-5-aryl-1-pyrroline N-oxides in good overall yields. Selected examples of 1,3-dipolar cycloaddition of the cyclic nitrones with methyl methacrylate were also described.
ipso Nitration. XXIII. Reactions of cyclohexadiene adducts from nitration of 4-ethyltoluene in acetic anhydride
Fischer, Alfred,Henderson, George N.
, p. 2314 - 2327 (2007/10/02)
The diastereoisomers of 4-ethyl-1-methyl-4-nitrocyclohexa-2,5-dienyl acetate (1) and 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dienyl acetate (2) are stereospecifically reduced to the corresponding nitrocyclohexadienols with aluminum hydride.Each dienol is stereospecifically methylated to the corresponding methyl ether with methyl iodide, silver oxide, and potassium hydroxide.Acid-catalysed solvolysis of the acetates 1 and 2 results in the substitution of the acetate moiety by other nucleophiles and these reactions are not stereospecific.The products of rearomatization of dienyl acetates, dienols and dienyl methyl ethers depend on the acidity and ionizing power of the solvents and are readily explained in terms of reactions involving a nitrocyclohexadienyl cation or acetoxy- (hydroxy-, methoxy-)cyclohexadienyl cation as key intermediates.In the 4-acetoxy-4-alkylcyclohexadienyl cation 1,2-migration of the acetoxyl group is more rapid then alkyl migration, but 1,2-alkyl migration is faster then migration of the hydroxyl or methoxyl groups in the corresponding cations. 1-Ethyl-4-methoxy-4-methylcyclohexa-2,5-dien-1-ol and 4-ethyl-3-nitrotoluene are significant minor products in the solvolysis of 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dien-1-ol in aqueous methanol.Nitration of p-ethyltoluene in the presence of sulfuric acid or in trifluoracetic anhydride gives a mixture of 4-ethyl-2-nitro- and 4-ethyl-3-nitrotoluene in a 2:1 ratio.
