共查询到20条相似文献,搜索用时 15 毫秒
1.
Aïcha Arfaoui Fatma Saâdi Asma Bourafai Aziez Hammouda Chebbi Catherine Fressigné Julien Legros 《合成通讯》2018,48(6):705-713
An efficient coupling reaction of allyl bromides with various alcohols as nucleophiles activated by triethylamine, leading to functionalized vinyl ethers in good yields and with full stereoselectivity. 相似文献
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Base-promoted reaction of dimethyl diazomethylphosphonate () with aliphatic ketones in the presence of allylic alcohols affords aldehydic allyl vinyl ethers (). 相似文献
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The reaction of allyl bromides with allyl tin reagents, catalyzed by palladium or zinc chloride gives cross-coupled products without allylic transpostion in the allyl halide partner but with predominate allylic rearrangement from the tin partner. 相似文献
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R. A. Bredikhin A. M. Maksimov V. E. Platonov 《Russian Journal of Organic Chemistry》2011,47(3):374-378
Reactions of polyfluoroarenesulfonyl bromides 4-XC6F4SO2Br (X = F, H, Cl, Br, CF3) with allyl bromide gave 84–94% of the corresponding allyl polyfluoroaryl sulfones. 相似文献
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(E)-beta-aryl vinyl iodides are synthesized in high yield with excellent stereoselectivity from benzyl bromides by a one-pot homologation/stereoselective elimination procedure. Convenient conditions involving the anion of diiodomethane and an excess of base provide complete consumption of the benzyl bromide and elimination from a diiodoalkane intermediate. Similar conditions provide (E)-beta-aryl vinyl chlorides and bromides by employing the anions of ICH(2)Cl or CH(2)Br(2). The functional group tolerance and facile purification allows rapid access to a wide range of functionalized vinyl halides. 相似文献
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Zanardi J Lamazure D Minière S Reboul V Metzner P 《The Journal of organic chemistry》2002,67(25):9083-9086
Asymmetric allylidenation of aldehydes with sulfur ylides is possible with proper substitution of the initial sulfide, to avoid the [2,3] sigmatropic rearrangement of the unsaturated ylides. One-pot reaction of (2R,5R)-dimethylthiolane with allyl halides, aldehydes, and sodium hydroxide in tert-butyl alcohol affords vinyl oxiranes in good yields. Enantiomeric excesses up to 90% and trans selectivities have been achieved with methallyl-type halides. 相似文献
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A. Van Veldhuizen M. Van Dijk G. M. Sanders 《Magnetic resonance in chemistry : MRC》1983,21(3):220-221
Chemical shifts are reported for quinolizinium bromide and 12 monosubstituted derivatives, carrying a bromohydroxy, diethylamino or piperidino group as the substituent. In addition, 1J(CH) values and long-range coupling constants are given. 相似文献
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Otto Meth-Cohn 《Tetrahedron letters》1985,26(15):1901-1904
N-Methylformanilide in phosphoryl chloride reacts with ketones, aldehyde and ketone enamines or enol acetates to give N-methylquinolinium salts in good yields. 相似文献
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The carbonylative addition between allyl halides and alkenes is described. The [2+2+1] reaction is catalyzed by Ni(I), and takes place with different strained alkenes under very mild conditions. Changes in solvent and use of different amounts of water in the reaction produce changes on the final products obtained. 相似文献
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Motoi Kawatsura 《Tetrahedron letters》2008,49(33):4873-4875
The ruthenium-catalyzed highly linear selective allylic amination of monosubstituted allylic acetates with secondary amines was developed. The regioselectivity was controlled by the Ru3(CO)12/2-DPPBA catalyst, and a linear-type aminated product was obtained as a single regioisomer. 相似文献
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The palladium-catalyzed 1,1-alkynylbromination of terminal alkenes with a silyl-protected alkynyl bromide is reported. The method tolerates a diverse range of alkenes including vinylarenes, acrylates, and even electronically unbiased alkene derivatives to afford propargylic bromides regioselectively. Mechanistic studies and DFT calculations indicate that the 1,1-alkynylbromination reaction proceeds via the migration of the Pd center followed by the formation of a π-allenyl Pd intermediate, leading to the stereoselective reductive elimination of the C(sp3)–Br bond at the propargylic positon.The first Pd-catalyzed 1,1-alkynylbromination of terminal alkenes using alkynyl bromides, which provides direct access to a variety of functionalized propargylic bromides without the need for an external brominating reagent, is reported. 相似文献
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Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as catalyst, a range of vinyl bromides undergoes Sonogashira cross-coupling reaction with a variety of alkynes, leading to the corresponding 1,3-enynes in good yields. The reaction tolerates several alkynes such as phenylacetylene, dec-1-yne, 2-methylbut-1-en-3-yne a range of alk-1-ynols, 3,3-diethoxyprop-1-yne and a propargyl amine. Higher reactions rates were observed in the presence of phenylacetylene, dec-1-yne, but-3-yn-1-ol, pent-4-yn-1-ol, 3,3-diethoxyprop-1-yne or 1,1-dipropyl-2-propynylamine than with propargyl alcohol, 3-methoxy-prop-1-yne or 2-methylbut-1-en-3-yne. This catalyst can be used at low loading even for reactions of sterically hindered vinyl bromides such as bromotriphenylethylene or 2-bromo-3-methyl-but-2-ene. 相似文献
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The relative thermodynamic stabilities of a number of isomeric allyl vinyl and propenyl vinyl ethers were determined by chemical equilibration in DMSO solution with KOBu-t as catalyst. From the temperature dependence of the values of the equilibrium constant the parameters G
m
, H
m
and S
m
of isomerization at 298.15 K were evaluated. Propenyl vinyl ethers, owing to their low enthalpy contents, are much more stable than the isomeric allyl vinyl ethers. It appears that in the parent propenyl vinyl ether, the Me group attached to C- of the divinyl ether skeleton has a strong stabilizing effect, comparable to that of alkyl groups in ordinary olefins, on the unsaturated system. In more heavily alkyl-substituted divinyl ethers, however, the stabilizing effects of alkyl groups are less prominent, being comparable to the low stabilization energies of alkyl groups in vinyl ethers, and depend moreover, on the pattern of substitution. 相似文献