5371-55-1Relevant academic research and scientific papers
TEMPO-Mediated Selective Synthesis of Isoxazolines, 5-Hydroxy-2-isoxazolines, and Isoxazoles via Aliphatic δ-C(sp3)-H Bond Oxidation of Oximes
Mondal, Santanu,Biswas, Sourabh,Ghosh, Krishna Gopal,Sureshkumar, Devarajulu
, p. 2439 - 2446 (2021/08/03)
Selective synthesis of three different bioactive heterocycles; isoxazolines, 5-hydroxy-2-isoxazolines and isoxazoles from the same starting material using TEMPO (2,2,6,6-Tetramethylpiperidin-1-oxyl) as a radical initiator is reported. Selectivity was achi
AgNO3as Nitrogen Source for Cu-Catalyzed Cyclization of Oximes with Isocyanates: A Facile Route to N-2-Aryl-1,2,3-triazoles
Liang, Jingwen,Rao, Yingqi,Zhu, Weidong,Wen, Tingting,Huang, Junjie,Chen, Zhichao,Chen, Lu,Li, Yibiao,Chen, Xiuwen,Zhu, Zhongzhi
supporting information, p. 7028 - 7032 (2021/09/14)
A versatile copper-catalyzed [3 + 1 + 1] annulation of oximes and isocyanates with AgNO3 is described. In this conversion, AgNO3 and isocyanates instead of conventional azide or diazonium reagents were used as the nitrogen source. This three-component transformation was achieved by cleaving N-O/C-H/C-N bonds and building CN/N-N bonds, which provides a strategy to prepare N-2-aryl-1,2,3-triazoles with a good substrate and functional compatibility.
Copper-Catalyzed Aza-Sonogashira Cross-Coupling To Form Ynimines: Development and Application to the Synthesis of Heterocycles
Lavernhe, Rémi,Torres-Ochoa, Rubén O.,Wang, Qian,Zhu, Jieping
supporting information, p. 24028 - 24033 (2021/10/07)
Nitrogen-substituted alkynes, such as ynamines and ynamides, are versatile synthetic building blocks. Ynimines bearing additional nucleophilic and electrophilic centers relative to ynamines and ynamides are expected to have high synthetic potential. However, their chemical reactivity remains unexplored owing mainly to the lack of synthetic accessibility. We report herein a versatile copper-catalyzed synthesis of ynimines from readily available O-acetyl ketoximes and terminal alkynes. A wide range of O-acetyl ketoximes derived from diaryl ketones, aryl alkyl ketones and dialkyl ketones underwent cross-coupling with a diverse set of terminal alkynes to afford the ynimines in good to excellent yields. An unprecedented [5+1] heteroannulation reaction exploiting the reactivity of the ynimine generated in situ was subsequently developed for the synthesis of medicinally important heterocycles, including isoquinolines, azaindoles, azabenzofurans, azabenzothiophenes and carbolines.
Transformations of Aryl Ketones via Ligand-Promoted C?C Bond Activation
Dai, Hui-Xiong,Li, Hanyuan,Li, Ling-Jun,Liu, Qi-Sheng,Ma, Biao,Wang, Mei-Ling,Wang, Xing,Wang, Zhen-Yu,Xu, Hui
supporting information, p. 14388 - 14393 (2020/07/06)
The coupling of aromatic electrophiles (aryl halides, aryl ethers, aryl acids, aryl nitriles etc.) with nucleophiles is a core methodology for the synthesis of aryl compounds. Transformations of aryl ketones in an analogous manner via carbon–carbon bond activation could greatly expand the toolbox for the synthesis of aryl compounds due to the abundance of aryl ketones. An exploratory study of this approach is typically based on carbon–carbon cleavage triggered by ring-strain release and chelation assistance, and the products are also limited to a specific structural motif. Here we report a ligand-promoted β-carbon elimination strategy to activate the carbon–carbon bonds, which results in a range of transformations of aryl ketones, leading to useful aryl borates, and also to biaryls, aryl nitriles, and aryl alkenes. The use of a pyridine-oxazoline ligand is crucial for this catalytic transformation. A gram-scale borylation reaction of an aryl ketone via a simple one-pot operation is reported. The potential utility of this strategy is also demonstrated by the late-stage diversification of drug molecules probenecid, adapalene, and desoxyestrone, the fragrance tonalid as well as the natural product apocynin.
Copper-Catalyzed Asymmetric Addition of Tertiary Carbon Nucleophiles to 2 H-Azirines: Access to Chiral Aziridines with Vicinal Tetrasubstituted Stereocenters
Hu, Haipeng,Xu, Jinxiu,Liu, Wen,Dong, Shunxi,Lin, Lili,Feng, Xiaoming
supporting information, p. 5601 - 5605 (2018/09/25)
A catalytic asymmetric nucleophilic addition of tertiary carbon nucleophiles to 2H-azirines was established in the presence of the chiral N,N′-dioxide/CuII complex. Various chiral aziridines with vicinal tetrasubstituted stereocenters were obta
Selectfluor-Bu4NI-Mediated C(sp3)-H Oxidation in Aqueous Media: Synthesis of Δ2-Isoxazolines from Oximes
Shi, Di,Qin, Hai-Tao,Zhu, Chen,Liu, Feng
supporting information, p. 5084 - 5088 (2015/08/18)
The direct functionalization of an aliphatic C-H bond within a complex molecule through a free-radical pathway is a valuable tool in synthetic chemistry. Herein, we developed an efficient transition-metal-free approach to generate Δ2-isoxazolines from oximes by radical-mediated C(sp3)-H oxidation. Investigation of the mechanism suggested that in the presence of Selectfluor and Bu4NI, the homolysis of the in situ formed O-I bond generated an iminoxyl radical that facilitated subsequent 1,5-H transfer and C(sp3)-H oxidation. The title reaction involves Selectfluor-Bu4NI-mediated C-O bond formation in aqueous media under metal-free conditions. A variety of Δ2-isoxazolines are directly synthesized from oximes by remote intramolecular functionalization of C(sp3)-H bonds.
Interplay of ortho-with spiro-cyclisation during iminyl radical closures onto arenes and heteroarenes
McBurney, Roy T.,Walton, John C.
supporting information, p. 1083 - 1092 (2013/07/19)
Sensitised photolyses of ethoxycarbonyl oximes of aromatic and heteroaromatic ketones yielded iminyl radicals, which were characterised by EPR spectroscopy. Iminyls with suitably placed arene or heteroarene acceptors underwent cyclisations yielding phenan
NEW ASPECTS IN THE HYDROGENOLYTIC OPENING OF 2-ISOXAZOLINES
Auricchio, Sergio,Ricca, Aldo
, p. 3983 - 3986 (2007/10/02)
It has been observed that the hydrogenolytic opening of 2-isoxazolines depends on the substituents present in positions 3 and 5.The hydrogenolysis on 10percent Pd/C of 2-isoxazolines, substituted in position 3 with carbonyl or carboxyl groups and in posit
