37629-37-1Relevant academic research and scientific papers
Metal-Free Deoxygenation of Chiral Nitroalkanes: An Easy Entry to α-Substituted Enantiomerically Enriched Nitriles
Pirola, Margherita,Faverio, Chiara,Orlandi, Manuel,Benaglia, Maurizio
supporting information, p. 10247 - 10250 (2021/06/18)
A metal-free, mild and chemodivergent transformation involving nitroalkanes has been developed. Under optimized reaction conditions, in the presence of trichlorosilane and a tertiary amine, aliphatic nitroalkanes were selectively converted into amines or nitriles. Furthermore, when chiral β-substituted nitro compounds were reacted, the stereochemical integrity of the stereocenter was maintained and α-functionalized nitriles were obtained with no loss of enantiomeric excess. The methodology was successfully applied to the synthesis of chiral β-cyano esters, α-aryl alkylnitriles, and TBS-protected cyanohydrins, including direct precursors of four active pharmaceutical ingredients (ibuprofen, tembamide, aegeline and denopamine).
Catalytic Asymmetric Construction of Tertiary Carbon Centers Featuring an α-Difluoromethyl Group with CF2H-CH2-NH2as the "building Block"
Gao, Fengyun,Guo, Yifei,Sun, Mengmeng,Wang, Yalan,Yang, Changyan,Wang, Yuqiang,Wang, Kairong,Yan, Wenjin
supporting information, p. 2584 - 2589 (2021/04/13)
We report here for the first time a novel difluoromethylated ketimine building block condensed by thioisatin and difluoroethylamine, offering efficient access to a broad range of enantioenriched products bearing difluoroethylamine units (27 examples, ≤98% yield, >99% ee) in the presence of quinine-derived squaramide. Further transformation of the intermediate would generate a variety of versatile functional blocks like α-difluoromethyl amines, β-amino acid, and β-diamine with retention of the enantiomeric excess at the difluoromethyl-bound carbon.
Dipolar HCP materials as alternatives to DMF solvent for azide-based synthesis
Bai, Rongxian,Gao, Feng,Gu, Yanlong,Li, Minghao
supporting information, p. 7499 - 7505 (2021/10/12)
Hypercrosslinked polymers HCP-DMF and HCP-DMF-SO3H containing abundant and flexible DMF moieties were designed and synthesized. Benefitting from the solvation microenvironment provided by the pseudo-DMF moities, the polar HCPs manifested outstanding performances in the conversions of NaN3 to benzylic azides and 1,2,3-triazoles in EtOH (95%), respectively, avoiding the use of risky DMF and improving the separation processes of the products.
Organocatalytic Asymmetric Synthesis of Aza-Spirooxindoles via Michael/Friedel-Crafts Cascade Reaction of 1,3-Nitroenynes and 3-Pyrrolyloxindoles
Ni, Qijian,Wang, Xuyang,Zeng, Da,Wu, Qianling,Song, Xiaoxiao
supporting information, p. 2273 - 2278 (2021/04/05)
An asymmetric [3+3] cyclization of nitroenynes and 3-pyrrolyloxindoles has been realized with a chiral bifunctional squaramide catalyst. This Michael/Friedel-Crafts cascade strategy provides a facile and efficient access to enantioenriched polycyclic aza-spirooxindoles with 32-95% isolated yields and excellent stereocontrol under mild reaction conditions.
Amides as surrogates of aldehydes for C-C bond formation: amide-based direct Knoevenagel-type condensation reaction and related reactions
Ou, Wei,Huang, Pei-Qiang
, p. 11 - 15 (2019/11/11)
Aldehydes are perhaps the most versatile compounds that enable many C-C bond forming reactions, which are not amenable for other subclasses of carbonyl compounds. We report the first use of amides as surrogates of aldehydes for C-C bond formation, namely,
tert-Butyl Nitrite Mediated Nitro-Nitratosation of Internal Alkenes
Mir, Bilal Ahmad,Rajamanickam, Suresh,Begum, Pakiza,Patel, Bhisma K.
, p. 2617 - 2625 (2020/05/08)
In an oxygen atmosphere tert-butyl nitrite (TBN) reacts with unsymmetrical internal benzylic alkenes giving nitro-nitratosation product exclusively. The γ-diaryl-substituted styrenes provided better yields compared to γ-alkyl-aryl-substituted styrenes. The higher yields for the former type of substrates is possibly dictated by the additional stability of benzylic radical due to the anchimeric assistance imparted by the γ-substituted phenyl ring. During oxidative nitration, the nitro (NO2) group adds at the non-benzylic site, whereas the nitrato group (ONO2) is attached at the relatively stable benzylic position. Under similar reaction conditions, α,β-unsaturated carboxylic acids, afforded nitroalkenes as the sole product.
Preparation method of beta-trans-nitroolefin
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Paragraph 0081-0083, (2020/06/17)
The invention relates to a preparation method of beta-trans-nitroolefin. The method comprises: sequentially adding an olefin compound, a nitration reagent and a solvent into a reaction container, mixing the substances uniformly, and carrying out constant temperature reaction for 18h under an illumination condition to obtain a reaction solution; and sequentially carrying out drying, concentration and column chromatography treatment on the reaction solution to obtain the beta-trans-nitroolefin compound. The method is simple and practicable, low in cost and high in product yield, can realize large-scale production, and has good industrial application prospects in the aspects of functional organic material, bioactive compound and drug synthesis.
Ionic-Liquid Controlled Nitration of Double Bond: Highly Selective Synthesis of Nitrostyrenes and Benzonitriles
Casiello, Michele,Caputo, Daniela,Fusco, Caterina,Cotugno, Pietro,Rizzi, Vito,Dell'Anna, Maria Michela,D'Accolti, Lucia,Nacci, Angelo
supporting information, p. 6012 - 6018 (2020/08/24)
Unprecedented in literature, the conversion of aryl alkenes into β-nitrostyrenes (2) or benzonitriles (3) with sodium nitrite can be governed by an appropriate choice of ionic liquid (IL) medium. A general trend was found for the selectivity of these processes, which depends on the nature of IL, with imidazolium-based ILs, such as [Bmim]Cl, that favor the C–H nitration leading to β-nitrostyrenes, while tetraalkylammonium-based ILs, such as TBAA, privilege the C=C bond cleavage affording benzonitriles. Besides a substrate scope, mechanistic hypotheses were provided on the origin of the different selectivity in the two kinds of ILs, based on their own tunable properties such as polarity, viscosity, and solvent cage effects.
Geometrically Selective Denitrative Trifluoromethylthiolation of β-Nitrostyrenes with AgSCF3for (E)-Vinyl Trifluoromethyl Thioethers
Fang, Ge,Hong, Jianquan,Huang, Shuai,Jiang, Chao,Liu, Yang,Zhang, Wei,Zheng, Changge
supporting information, (2020/07/03)
An efficient copper(II)-promoted denitrative trifluoromethylthiolation under mild reaction conditions has been developed for vinyl trifluoromethyl thioethers to construct Cvinyl-SCF3 bonds with stable AgSCF3 as a source of the trifluoromethylthio. This reaction system tolerates a broad range of functional groups to commendably achieve a high product yield and excellent stereoselectivity of E/Z.
