115665-95-7Relevant articles and documents
Exploiting the chiral ligands of bis(Imidazolinyl)-and bis(oxazolinyl)thiophenes—Synthesis and application in Cu-catalyzed friedel–crafts asymmetric alkylation
Al-Majid, Abdullah Mohammed,Alammari, Abdullah Saleh,Alshahrani, Saeed,Barakat, Assem,Haukka, Matti,Islam, Mohammad Shahidul
, (2021/12/17)
Five new C2-symmetric chiral ligands of 2,5-bis(imidazolinyl)thiophene (L1–L3) and 2,5-bis(oxazolinyl)thiophene (L4 and L5) were synthesized from thiophene-2,5-dicarboxylic acid (1) with enantiopure amino alcohols (4a–c) in excellent optical purity and chemical yield. The util-ity of these new chiral ligands for Friedel–Crafts asymmetric alkylation was explored. Subse-quently, the optimized tridentate ligand L5 and Cu(OTf)2 catalyst (15 mol%) in toluene for 48 h promoted Friedel–Crafts asymmetric alkylation in moderate to good yields (up to 76%) and with good enantioselectivity (up to 81% ee). The bis(oxazolinyl)thiophene ligands were more potent than bis(imidazolinyl)thiophene analogues for the asymmetric induction of the Friedel–Crafts asymmetric alkylation.
Preparation method of beta-trans-nitroolefin
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Paragraph 0027-0029; 0063-0065, (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.
Metal-free, room temperature, acid-K2S2O8 mediated method for the nitration of olefins: An easy approach for the synthesis of nitroolefins
Ambala, Srinivas,Singh, Rohit,Singh, Maninder,Cham, Pankaj Singh,Gupta, Ria,Munagala, Gurunadham,Yempalla, Kushalava Reddy,Vishwakarma, Ram A.,Singh, Parvinder Pal
, p. 30428 - 30431 (2019/10/04)
Here, we have developed a simple, room temperature method for the nitration of olefins by using inexpensive sodium nitrite as a source of nitro groups in the presence of trifluoroacetic acid (TFA) and potassium persulfate (K2S2O8) under an open atmosphere. Styrenes and mono-substituted olefins give stereo-selective corresponding E-nitroolefins under optimized conditions, however, 1,1-bisubstituted olefins give a mixture of E- and Z-nitroolefins. The optimized conditions work well with electron-donating, electron-withdrawing, un-substituted and heterocyclic styrenes and mono-substituted olefins and give corresponding nitroolefins with good to excellent yields.