56517-81-8Relevant academic research and scientific papers
Synthesis of Isoselenazoles and Isothiazoles from Demethoxylative Cycloaddition of Alkynyl Oxime Ethers
Zhang, Zhu-Zhu,Chen, Rong,Zhang, Xiao-Hong,Zhang, Xing-Guo
, p. 632 - 642 (2020/12/22)
A general method for the synthesis of isoselenazoles and isothiazoles has been developed by the base-promoted demethoxylative cycloaddition of alkynyl oxime ethers using the cheap and inactive Se powder and Na2S as selenium and sulfur sources. This transformation features the direct construction of N-, Se-, and S-containing heterocycles through the formation of N-Se/S and C-Se/S bonds in one-pot reactions with excellent functional group tolerance.
Synthesis of 2-isoxazolyl-2,3-dihydrobenzofuransviapalladium-catalyzed cascade cyclization of alkenyl ethers
Zhou, Fei,Li, Can,Li, Meng,Jin, Yangbin,Jiang, Huanfeng,Zhang, Yingjun,Wu, Wanqing
supporting information, p. 4799 - 4802 (2021/05/25)
A novel palladium-catalyzed cascade cyclization reaction of alkenyl ethers with alkynyl oxime ethers for the construction of poly-heterocyclic scaffolds has been developed, in which the electron-rich alkene moiety functions as a three-atom unit, simultaneously dealing well with the coordination and regioselectivity of electron-rich olefins under metal catalysis. The strategy features excellent regio- and chemoselectivities as well as good functional group tolerance. Moreover, the newly formed 2-isoxazolyl-2,3-dihydrobenzofuran products can be further transformed to diverse complex heterocycles, demonstrating their potential applications in organic synthesis and medicinal chemistry.
Straightforward Stereoselective Synthesis of Seven-Membered Oxa-Bridged Rings through in Situ Generated Cycloheptenol Derivatives
Wang, Mengdan,Yin, Liqiang,Cheng, Lu,Yang, Yajie,Li, Yanzhong
, p. 12956 - 12963 (2021/09/13)
An iodine-mediated stereoselective synthesis of seven-membered oxa-bridged rings via in situ generated cycloheptenols was reported. This process was realized through the combination of C-C σ-bond cleavage and C-O bond-forming reactions in a one-pot fashion from simple and easily accessible raw materials. The formation of carbon radicals initiated by I2 was the key to the reaction.
Recyclable heterogeneous palladium-catalyzed carbonylative Sonogashira coupling under CO gas-free conditions
Zhou, Zebiao,Li, Jianying,Xu, Zhaotao,Cai, Mingzhong
supporting information, p. 2015 - 2025 (2020/05/13)
A convenient, efficient and practical heterogeneous palladium-catalyzed carbonylative Sonogashira coupling of aryl iodides with terminal alkynes under CO gas-free conditions has been developed by using an MCM-41-supported bidentate phosphine palladium ace
Bifunctional phosphine ligand-enabled gold-catalyzed direct cycloisomerization of alkynyl ketones to 2,5-disubstituted furans
Hu, Xiaojun,Zhou, Bingwei,Jin, Hongwei,Liu, Yunkui,Zhang, Liming
supporting information, p. 7297 - 7300 (2020/07/14)
An efficient synthesis of 2,5-disubstituted furans directly from alkynyl ketones has been developed via tandem gold(i)-catalyzed isomerization of alkynyl ketones to allenyl ketones and cycloisomerization. The key to the success of this chemistry is the use of a biphenyl-2-ylphosphine ligand featuring a critical remote tertiary amino group.
Alkynyl?B(dan)s in Various Palladium-Catalyzed Carbon?Carbon Bond-Forming Reactions Leading to Internal Alkynes, 1,4-Enynes, Ynones, and Multiply Substituted Alkenes
Tani, Tomohiro,Sawatsugawa, Yuuki,Sano, Yusuke,Hirataka, Yo,Takahashi, Naomi,Hashimoto, Sadahiro,Sugiura, Tetsuya,Tsuchimoto, Teruhisa
supporting information, p. 1815 - 1834 (2019/03/07)
It was found that the C(sp)?B(dan) bond of alkynyl?B(dan)s can be directly used for palladium-catalyzed carbon?carbon bond-forming reactions with aryl(alkenyl) halides and allylic carbonates as electrophiles, thus delivering unsymmetrical internal alkynes and unconjugated 1,4-enynes, respectively. With acyl chlorides as electrophiles, ynone synthesis is also promoted by a palladium catalyst with the assistance of a copper co-catalyst. These reactions can be achieved as more convenient one-pot reactions, without isolating the alkynyl?B(dan) formed in situ by the zinc-catalyzed dehydrogenative borylation of alkynes with HB(dan). In addition to direct C(sp)?B(dan) bond transformations, the C≡C bond in an alkynyl?B(dan) proved to be a promising scaffold for the construction of a multisubstituted alkene, which is synthesized by diboration of the C≡C?B(dan) moiety, leading to a triborylalkene followed by iterative regio- and stereoselective Suzuki?Miyaura cross-coupling reactions. As one example, the synthesis of the ethene with four different aryl groups, p-MeC6H4, p-MeOC6H4, p-NCC6H4, and p-F3CC6H4, was attained in high overall yield of 64% in six steps starting from the terminal alkyne, p-MeC6H4C≡CH. Besides these synthetic applications of the alkynyl?B(dan), the scope of the alkynyl substrate in the zinc-catalyzed dehydrogenative borylation was expanded to enhance the reliability as a provider of the alkynyl?B(dan). Consequently, 42 alkynes were found to participate in the dehydrogenative borylation as substrates; these are alkyl-, alkenyl-, aryl-, heteroaryl-, ferrocenyl-, silyl-, and borylalkynes, with or without a variety of functional groups. Lastly, a new method for preparing HB(dan), as a sulfide-free, cost-saving, and reaction-time-saving route, is disclosed. (Figure presented.).
Palladium-Catalyzed Cascade Annulation/Allylation of Alkynyl Oxime Ethers with Allyl Halides: Rapid Access to Fully Substituted Isoxazoles
Li, Can,Li, Jianxiao,Zhou, Fei,Li, Chaosheng,Wu, Wanqing
, p. 11958 - 11970 (2019/10/11)
A novel and efficient approach for the synthesis of functionalized isoxazoles via palladium-catalyzed cascade annulation/allylation of alkynyl oxime ethers with allyl halides has been established. The present protocol exhibits mild reaction conditions, good functional group compatibility, and convenient operation. Moreover, scalability was performed and further decoration of the isoxazole product was achieved.
An easy access towards quinazolines via an improved protocol for ynones
Ghosh, Subhadeep,Das, Asish R.
, p. 1249 - 1258 (2020/06/27)
A simple and convenient method has been developed to accomplish Pt/2,2'-bipyridyl catalyzed acyl Sonagashira coupling for the efficient synthesis of ynones. The reaction display significant tolerance to various functional groups and the methodology has be
Application of phase-vanishing method with CO gas evolution to carbonylation reactions
Adachi, Yusuke,Matsubara, Hiroshi
, p. 89 - 95 (2018/10/26)
Although carbon monoxide (CO) is considered a practical source of the carbonyl functionality in various compounds, handling CO gas is difficult. The phase-vanishing (PV) method, using highly fluorinated solvents as the phase screen, was thus employed, in which CO was evolved for use in organic synthesis. An H-shaped reactor bearing two reaction chambers was employed. In the first chamber, CO was efficiently generated from sulfuric acid and ammonium formate under the PV conditions, and then consumed in the second chamber in a range of palladium-catalysed carbonylation reactions, affording the desired products. Use of this PV system allowed for easy and safe generation of hazardous CO gas, and its use thereof in organic synthesis.
PHOSPHINE COMPOUND HAVING PERFLUORO GROUP, AND COMPLEX BETWEEN METAL AND PHOSPHINE HAVING PERFLUORO GROUP
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Paragraph 0275-0276; 0278-0281; 0283-0285, (2018/10/16)
PROBLEM TO BE SOLVED: To provide a perfluoroalkylphosphine compound, and a complex between a metal and the perfluoroalkylphosphine. SOLUTION: A perfluoroalkylphosphine compound is a phosphine compound represented by the general formula Rf-PR1R2. In the formula, R1 and R2 are each independently a substituted or unsubstituted hydrocarbon group; Rf is a perfluorinated hydrocarbon group. Also provided is a complex between the perfluoroalkylphosphine and a phosphine coordination metal. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
