共查询到20条相似文献,搜索用时 15 毫秒
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This Letter describes the amination of 3-bromoisoxazoles by a nucleophilic aromatic substitution reaction. We have found 3-bromoisoxazoles to be inert to substitution under thermal conditions, however, the employment of phosphazene bases under microwave irradiation facilitates the amination process and allows the corresponding 3-aminoisoxazoles to be isolated in moderate yield. 相似文献
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Radhey S Srivastava 《Tetrahedron letters》2003,44(16):3271-3274
The transition metal catalyzed allylic amination of olefins are studied. A screening of catalysts known for the intermediacy of PhNO in the amination of alkene with phenylhydroxylamine reveals that the hydrated copper salt in conjugation with copper powder as reductant has the best catalytic properties using nitrosobenzene as nitrogen-fragment donor. The catalytic system has been studied for a variety of alkenes. Unsymmetrical alkenes react with high regioselectivity with N-functionalization at the less substituted vinylic carbon. 相似文献
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Gregg A Hogan August A Gallo Kenneth M Nicholas Radhey S Srivastava 《Tetrahedron letters》2002,43(52):9505-9508
The copper(I) complex [Cu(CH3CN)4]PF6 catalyzes the allylic amination of alkenes by aryl hydroxylamine in fair to moderate yields. Unsymmetrical alkenes react with high regioselectivity with N-functionalization occuring at the less substituted vinylic carbon. Trapping experiments indicate that free PhNO is not an intermediate in these reactions. 相似文献
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In this study, we aimed to develop a simple and efficient method for the electrophilic amination of organozinc reagents. For this reason, 12 cosolvents were screened in the electrophilic amination of ordinary organozinc reagents. By the use of a cosolvent, an easily applicable and high‐yielding method for the preparation of arylamines by electrophilic amination of arylzinc reagents was developed. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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<正>"One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide(HMPT) media without the protection of aldehyde groups. 相似文献
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Ya. L. Gol'dfarb S. D. Pirozhkov V. P. Litvinov A. A. Dudinov M. A. Buiya A. L. Lapidus 《Russian Chemical Bulletin》1987,36(10):2080-2083
Conclusions Palladium complexes of the general formula PdCl2L2 (L=tri(thienyl)phosphine) are active and selectively reacting catalysts in the carbonylation of C2-C18 -olefins.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2245–2248, October, 1987. 相似文献
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A novel electrolytic transformation of olefins into oxyselenides has been performed in high yields and high regioselectivities by elctrolyzing olefins in protic solvents (MeOH, AcOH, H2O-MeCN) containing Et4NX (X = Cl, Br, I) and diphenyl diselenide using platinum foils. 相似文献
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Yukiko Tsuchi Hirotaka Watanabe Masaki Kogawa Biao Zhou Hiroaki Tsuji Motoi Kawatsura 《Tetrahedron letters》2018,59(13):1264-1267
We accomplished the palladium-catalyzed double substitution of 2-haloallylic acetates with nitrogen nucleophiles. During the Pd2(dba)3/DPPE-catalyzed reaction of 2-fluoroallylic acetates with N-substituted-p-toluenesulfonamide, two equivalents of nitrogen nucleophiles were introduced to the allyl unit with a Z-selectivity through the carbon–fluorine bond cleavage. We further demonstrated the reaction of 2-chloroallylic acetates, and succeeded in obtaining the same doubly-substituted products in good yields with a high Z-selectivity. 相似文献
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Brice JL Harang JE Timokhin VI Anastasi NR Stahl SS 《Journal of the American Chemical Society》2005,127(9):2868-2869
The first examples of palladium-catalyzed oxidative amination of unactivated alkyl olefins have been identified. To be successful, these reactions must be conducted under cocatalyst-free conditions that involve direct dioxygen-coupled turnover of the palladium catalyst. The oxidative amination products of norbornene and other cyclic alkenes implicate a cis-aminopalladation mechanism. 相似文献
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Nicolle Schwarz 《Tetrahedron letters》2007,48(16):2897-2900
The palladium-catalyzed amination of a 3-silyloxy-substituted bromo-indole with primary and secondary amines is described for the first time. In the presence of the novel catalyst system of Pd(OAc)2/N-phenyl-2-(di-1-adamantylphosphino)pyrrole potentially bioactive amino-functionalized indole derivatives are obtained in a general manner in high yield. 相似文献
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Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, p. 743, March, 1989. 相似文献
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Micro reactor technology was successfully applied in the palladium catalysed C-N cross-coupling reaction between 4-bromotoluene and piperidine. Excellent conversions and selectivities were obtained without any by-product formation in continuous reactor. 相似文献
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Soufiane El Houssame Hafid Anane Larbi El Firdoussi Abdellah Karim 《Central European Journal of Chemistry》2008,6(3):470-476
The palladium(0) catalyzed amination of allylic acetates and carbonates derivatives from terpenic olefins was carried out
under mild conditions. The reaction offers a very good method for the preparation of allylic amines and thus to provide a
useful entry to new functionalized terpenic olefin products. The mechanism involving a formation of p-allyl-palladium intermediate
complex is in good agreement with the results obtained with the optically active substrates, as well as via an analysis of
the observed regio-and stereoselectivity.
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Barluenga J Fernández MA Aznar F Valdés C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(8):2276-2283
A novel approach for the synthesis of the important indole ring is described. Indoles are obtained from o-bromoanilines and alkenyl halides in a Pd-catalyzed cascade process that involves an alkenyl amination followed by an intramolecular Heck reaction. The overall process represents the first example of the participation of alkenyl amination reactions in Pd-catalyzed cascade reactions. Initially, the relative reactivity of aryl and alkenyl bromides and chlorides towards Pd-catalyzed amination was investigated. Competition experiments were carried out in the presence of primary and secondary amines, and these revealed the reactivity order alkenyl bromides > aryl bromides > alkenyl chlorides > aryl chlorides, as well as very high chemoselectivity; the more reactive halide was always favored. Thereafter, optimized reaction conditions for the sequential alkenyl amination/Heck cyclization to give indoles were investigated with the model reaction of o-bromoaniline with alpha-bromostyrene. An extensive screening of ligands, bases, and reaction conditions revealed that the [Pd2(dba)3]/DavePhos, NaOtBu, toluene combination at 100 degrees C were the optimized reaction conditions to carry out the cascade process (dba=dibenzylideneacetone, DavePhos=2-dicyclohexylphosphino-2'-N,N-dimethylaminobiphenyl). The reaction proceeds with aryl, alkyl, and functionalized substitutents in both starting reactants. The cyclization was also studied with N-substituted o-bromoanilines (which would give rise to N-substituted indoles); however, in this case, indole formation occurred only with 1-substituted-2-bromoalkenes. Finally, the application of this methodology to o-chloroanilines required further optimization. Although the catalyst based on DavePhos failed to promote the cascade process, a catalytic combination based on [Pd2(dba)3]/X-Phos promoted the formation of the indole ring also from the less reactive chloroanilines. 相似文献
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[reaction: see text] Palladium(II) complexes bearing a single N-heterocyclic carbene ligand serve as effective catalysts for the aerobic oxidative cyclization of alkenes with pendant sulfonamides. The use of carboxylic acid cocatalysts (AcOH and PhCO(2)H) often leads to significant improvements in catalyst stability and product yield and enables catalytic turnover to be achieved with air, rather than pure oxygen gas, as the source of O(2). 相似文献
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