- Iron-Catalyzed Reductive Cyclization by Hydromagnesiation: A Modular Strategy Towards N-Heterocycles
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A reductive cyclization to prepare a variety of N-heterocycles, through the use of ortho-vinylanilides, is reported. The reaction is catalyzed by an inexpensive and bench-stable iron complex and generally occurs at ambient temperature. The transformation likely proceeds through hydromagnesiation of the vinyl group, and trapping of the in situ generated benzylic anion by an intramolecular electrophile to form the heterocycle. This iron-catalyzed strategy was shown to be broadly applicable and was utilized in the synthesis of substituted indoles, oxindoles and tetrahydrobenzoazepinoindolone derivatives. Mechanistic studies indicated that the reversibility of the hydride transfer step depends on the reactivity of the tethered electrophile. The synthetic utility of our approach was further demonstrated by the formal synthesis of a reported bioactive compound and a family of natural products.
- Larin, Egor M.,Lautens, Mark,Loup, Joachim
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p. 22345 - 22351
(2021/09/09)
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- Hydroxyl Assisted Rhodium Catalyst Supported on Goethite Nanoflower for Chemoselective Catalytic Transfer Hydrogenation of Fully Converted Nitrostyrenes
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Control of chemoselectivity is a special challenge for the reduction of nitroarenes bearing one or more unsaturated groups. Here, we report a flower-like Rh/α-FeOOH catalyst for the chemoselective hydrogenation of nitrostyrene to vinylaniline over full conversion, which benefits the new functionalized aminostyrene because the multisubstituted aminostyrenes are usually commercially unavailable. This catalyst does not only show desirable selectivity for the vinylanilines, but also exhibits the inertness to various other reducible groups over wide reaction duration. The catalytic selectivity for the reduction of the nitro group towards vinyl group was investigated by the control experiments and FT-IR analysis. We have found that the abundant hydroxyl groups in the α-FeOOH may contribute to the improvement of catalytic activity and selectivity. Furthermore, the catalyst exhibits excellent stability and keeps its catalytic performance even after 6 cycles. (Figure presented.).
- Hu, Zenan,Ai, Yongjian,Liu, Lei,Zhou, Junjie,Zhang, Gang,Liu, Hongqi,Liu, Xiangyu,Liu, Zhibo,Hu, Jianshe,Sun, Hong-bin,Liang, Qionglin
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supporting information
p. 3146 - 3154
(2019/05/10)
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- PYRIMIDINES AND VARIANTS THEREOF, AND USES THEREFOR
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The present disclosure provides pyrimidine compounds of Formula 1 and uses thereof, for example, for the potential treatment of diseases associated with P2X purinergic receptors. In certain aspects, the present disclosure provides P2X3 and/or P2X2/3 antagonists which are useful, for example, for the potential treatment of visceral organ, cardiovascular and pain-related diseases, conditions and disorders.
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Paragraph 0625; 0627; 0629; 0630
(2018/12/03)
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- Palladium-Catalyzed Synthesis of Indoles by Reductive N-Heteroannulation of 2-Nitrostyrenes
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A palladium-phosphine catalyzed reductive N-heteroannulation of 2-nitrostyrenes, in the presence of carbon monoxide, producing indoles has been developed. Indoles were obtained, in moderate to excellent yield, from substituted 2-nitrostyrenes having either electron-withdrawing (NO2 and CO2-Me) or electron-donating (Br, OH, Me, OMe, and OTf) substituents on the aromatic ring. Best results were obtained using palladium diacetate (6 mol percent) together with triphenylphosphine (24 mol percent) as the catalytic system, under 4 atm of carbon monoxide in acetonitrile at 70 °C. Other palladium(II) and palladium(0) complexes also catalyze the reaction.
- So?derberg, Bjo?rn C.,Shriver, James A.
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p. 5838 - 5845
(2007/10/03)
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- A Regiocontrolled Synthesis of Substituted Indoles by Palladium-Catalyzed Coupling of 2-Bromonitrobenzenes and 2-Bromoacetanilides
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The palladium-catalyzed cross-coupling reaction of 2-bromonitrobenzenes or 2-bromoacetanilides with ethylene has been used to produce a variety of substituted indoles.The mild reaction conditions and selectivity inherent in the coupling reaction have been utilized to produce regiochemically pure 4-, 5-, 6-, and 7-substituted indoles.
- Kasahara, Akira,Izumi, Taeko,Murakami, Satoshi,Miyamoto, Kazuhiro,Hino, Toshimi
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p. 1405 - 1413
(2007/10/02)
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