5582-87-6Relevant academic research and scientific papers
Method for high-selectivity reduction of nitroolefin C=C double bonds
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Paragraph 0053-0056; 0061-0063, (2021/06/21)
The invention provides a method for high-selectivity reduction of nitroolefin C=C double bonds. According to the method, a bidentate nitrogen ligand-[Cp* IrCl2] complex is used as the catalyst, nitroolefin can be conveniently converted into nitroalkane, the catalytic efficiency is extremely high, and the substrate conversion rate is 99% or above. The high-purity nitroalkane can be separated through simple extraction, liquid separation and solvent removal under reduced pressure. The selected solvent is water or a mixture of water and a hydrophilic solvent. The method is green, environment-friendly and high in reaction efficiency. The nitroalkane compound prepared by the invention is a very important organic intermediate, and has wide application in the fields of national defense, pesticide, biology, medicine, fine chemical engineering and the like.
Iridium-catalyzed highly chemoselective and efficient reduction of nitroalkenes to nitroalkanes in water
Chen, Yang,Liu, Changmeng,Xu, Dong,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 6050 - 6058 (2021/08/23)
An iridium-catalyzed highly chemoselective and efficient transfer hydrogenation reduction of structurally diverse nitroalkenes was realized at very low catalyst loading (S/C = up to 10000 or 20?000), using formic acid or sodium formate as a traceless hydride donor in water. Excellent functionality tolerance is also observed. The turnover number and turnover frequency of the catalyst reach as high as 18?600 and 19?200 h-1, respectively. An inert atmosphere protection is not required. The reactivities of nitroalkenes are dependent on their substitution pattern, and the pH value is a key factor to accomplish the complete conversion and excellent chemoselectivity. Purification of products is achieved by simple extraction without column chromatography. The reduction procedure is facilely amplified to 10 g scale at 10?000 S/C ratio. The potential of this green reduction in enantioselective hydrogenation has been demonstrated.
Boosting Conjugate Addition to Nitroolefins Using Lithium Tetraorganozincates: Synthetic Strategies and Structural Insights
Dell'Aera, Marzia,Perna, Filippo Maria,Vitale, Paola,Altomare, Angela,Palmieri, Alessandro,Maddock, Lewis C. H.,Bole, Leonie J.,Kennedy, Alan R.,Hevia, Eva,Capriati, Vito
supporting information, p. 8742 - 8748 (2020/07/04)
We report the first transition metal catalyst- and ligand-free conjugate addition of lithium tetraorganozincates (R4ZnLi2) to nitroolefins. Displaying enhanced nucleophilicity combined with unique chemoselectivity and functional group tolerance, homoleptic aliphatic and aromatic R4ZnLi2 provide access to valuable nitroalkanes in up to 98 % yield under mild conditions (0 °C) and short reaction time (30 min). This is particularly remarkable when employing β-nitroacrylates and β-nitroenones, where despite the presence of other electrophilic groups, selective 1,4 addition to the C=C is preferred. Structural and spectroscopic studies confirmed the formation of tetraorganozincate species in solution, the nature of which has been a long debated issue, and allowed to unveil the key role played by donor additives on the aggregation and structure of these reagents. Thus, while chelating N,N,N’,N’-tetramethylethylenediamine (TMEDA) and (R,R)-N,N,N’,N’-tetramethyl-1,2-diaminocyclohexane (TMCDA) favour the formation of contacted-ion pair zincates, macrocyclic Lewis donor 12-crown-4 triggers an immediate disproportionation process of Et4ZnLi2 into equimolar amounts of solvent-separated Et3ZnLi and EtLi.
An efficient method for the synthesis of α-arylated nitroalkanes and α-arylated hydroximoyl chlorides mediated by AlCl3
Tu, Zhijay,Rama Raju,Liou, Tzuo-Rung,Kavala, Veerababurao,Kuo, Chun-Wei,Jang, Yaochung,Shih, Yu-Hsuan,Wang, Chun-Chao,Yao, Ching-Fa
experimental part, p. 2436 - 2442 (2009/07/25)
Friedel-Crafts alkylation of various arenes/heteroarenes to β-nitrostyrenes mediated by aluminum chloride is described. The interesting feature of this methodology pertain the formation of different products by tuning the reaction temperature. α-Arylated
Palladium(II)-catalyzed conjugate addition of arylsiloxanes in water
Lerebours, Rachel,Wolf, Christian
, p. 2737 - 2740 (2008/02/07)
Equation Presented Palladium-phosphinous acids catalyze the conjugate addition of arylsiloxanes to a wide range of α.β-unsaturated substrates in water microwave-assisted procedure is described that uses 5 mol % of POPd1 to afford /-substituted ketones, aldehydes, esters, nitriles, an nitroalkanes in 83% to 96% yield within 4 h. This method eliminates the need for stoichiometric additives and an excess of arylsiloxane, an does not require an inert atmosphere.
Palladium-bipyridine catalyzed conjugate addition of arylboronic acids to α,β-unsaturated carbonyl compounds in aqueous media
Lin, Shaohui,Lu, Xiyan
, p. 7167 - 7170 (2007/10/03)
Palladium/bipyridine catalyzed conjugate addition of arylboronic acids to α,β-unsaturated carbonyl compounds in aqueous media was developed with high yields.
Pd(II)-bipyridine catalyzed conjugate addition of arylboronic acid to α,β-unsaturated carbonyl compounds
Lu, Xiyan,Lin, Shaohui
, p. 9651 - 9653 (2007/10/03)
A Pd(II)-catalyzed conjugate addition of arylboronic acid to α,β-unsaturated ketones, aldehydes, esters, etc. in the presence of 2,2′-bipyridine was developed. A mechanism involving transmetalation, insertion of the carbon-carbon double bond into the C-Pd bond, and protonolysis of the resulting C-Pd bond is proposed. The reaction conditions are mild and the yield is high. The presence of 2,2′-bipyridine is crucial for the reaction to inhibit β-hydride elimination.
Synthesis of nitrogen-functionalized cyclohexanes using chemoselective conjugate addition of phenyllithium to linear ω-nitro-α,β, ψ,ω-unsaturated ester and subsequent stereoselective intramolecular nitro-Michael cyclization
Yasuhara, Tomohisa,Nishimura, Katsumi,Osafune, Emi,Muraoka, Osamu,Tomioka, Kiyoshi
, p. 1109 - 1113 (2007/10/03)
Nitrogen-functionalized cyclohexane derivatives with three contiguous chiral centers were synthesized by nitroalkene-selective conjugate addition of phenyllithium to a ω-nitro-α,β,ψ, ω-unsaturated ester and subsequent stereocontrolled intramolecular nitro
Palladium(II)-catalyzed Michael-type hydroarylation of nitroalkenes using aryltins and sodium tetraarylborates
Ohe, Toshiyuki,Uemura, Sakae
, p. 1423 - 1431 (2007/10/03)
A variety of aryltin compounds and sodium tetraarylborates can be employed for Michael-type hydroarylation reactions of nitroalkenes to afford β-arylnitroalkanes in moderate to good yields in the presence of either LiCl, MgCl2, or CaCl2 and a catalytic amount of palladium(II) salt (0.05 molar amount) in acetic acid. Results show that 50-70% of aryl groups out of all in these aryl compounds can be transferred to the products in this hydroarylation. The addition of a catalytic amount (0.05-0.10 molar amount) of a Lewis acid chloride, BiCl3 or SbCl3, much improves the product yield in some cases.
Palladium-catalyzed conjugate addition of organosiloxanes to α,β-unsaturated carbonyl compounds and nitroalkenes
Denmark, Scott E.,Amishiro, Nobuyoshi
, p. 6997 - 7003 (2007/10/03)
The addition of aryltrialkoxysilanes to α,β-unsaturated carbonyl compounds (ketones, aldehydes) and nitroalkenes in the presence of SbCl3, TBAF, AcOH, and a catalytic amount of Pd(OAc)2, in CH3CN at 60 °C, provides the corresponding conjugate addition products in moderate to good yields. The addition of equimolar amounts of SbCl3 and TBAF is necessary for this reaction to proceed smoothly. The arylpalladium complex, which is generated by the transmetalation from a putative hypercoordinate silicon compound, is considered to be the catalytically active species.
