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Search for "vinylic substitution" in Full Text gives 8 result(s) in Beilstein Journal of Organic Chemistry.
Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides
Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111
- cycloaddition or addition–elimination reactions with 1,3-dipoles and gem-difluoroalkenes is largely unexplored and the only report of a cycloaddition is with 2-fluoroindolizines (Figure 1A) via a β-fluoride elimination in an SNV (nucleophilic vinylic substitution)-like transformation [9]. Nucleophilic addition
- azido amine intermediate INT-3 can be formed via vinylic substitution of INT-1 with an azide which can cyclize to form INT-4 that subsequently aromatizes to afford product 3 (route B). To demonstrate the applicability of this method, a scale-up reaction was performed using 150 mg of the limiting reagent
Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities
Beilstein J. Org. Chem. 2022, 18, 524–532, doi:10.3762/bjoc.18.54
- ± 0.04 µM (100 ng/mL, 200 nM), respectively. Two compounds (3b and 10d) have also been tested for anti-SARS-CoV-2, antibacterial, and cytotoxic activity. Keywords: antimalarial activity; anti-SARS-CoV-2 activity; chloroquine; 2-nitroperchlorobutadiene; nucleophilic vinylic substitution; 1H-pyrazoles
Facile synthesis of 4H-chromene derivatives via base-mediated annulation of ortho-hydroxychalcones and 2-bromoallyl sulfones
Beilstein J. Org. Chem. 2016, 12, 16–21, doi:10.3762/bjoc.12.3
- furnished 3-arylsulfonyl-4H-chromene derivatives in 58–67% yield (18 examples). 2-Bromoallyl sulfones functioned as synthetic surrogates for allenyl sulfones in the reaction. Keywords: allenes; chromenes; cyclocondenzation; sulfones; vinylic substitution; Findings Benzo[b]dihydropyran, commonly known as
- 1, path a). Bromoallyl sulfones 2a,b partake in a cesium carbonate-mediated formal vinylic substitution reaction with heteronucleophiles to afford valuable multifunctional building blocks [23]. For example, the reaction of 2a with 4-chlorophenol afforded the enol ether 3 in 84% yield (Scheme 1, path
Chemistry of polyhalogenated nitrobutadienes, 14: Efficient synthesis of functionalized (Z)-2-allylidenethiazolidin-4-ones
Beilstein J. Org. Chem. 2014, 10, 1638–1644, doi:10.3762/bjoc.10.170
- an appropriate nucleophile at the activated terminal carbon atom of the nitrodichlorovinyl group within 1 to undergo a vinylic substitution. Thus, in case of, e.g., sulfur nucleophiles, the corresponding thioperchlorobutadiene derivatives are easily accessible [2][5][16][17]. In this paper, we
- released. Moreover, nitrodiene 1 was subjected to a vinylic substitution with ethyl 2-mercaptopropanoate to give ethyl 2-[(1,3,4,4-tetrachloro-2-nitrobuta-1,3-dien-1-yl)thio]propanoate (29) as an inseparable mixture of Z- and E-isomers in a 4:1 ratio with 78% total yield. Treatment of dienes (Z,E)-29 with
Use of activated enol ethers in the synthesis of pyrazoles: reactions with hydrazine and a study of pyrazole tautomerism
Beilstein J. Org. Chem. 2014, 10, 752–760, doi:10.3762/bjoc.10.70
- ethers react surprisingly easily with various nucleophiles such as amines, thiols, alcohols or C-anions [2] under the conditions of nucleophilic vinylic substitution [3]. When using bi- or trifunctional nucleophiles, cyclic or bicyclic products are formed. Activated enol ethers thus represent
Carbenoid-mediated nucleophilic “hydrolysis” of 2-(dichloromethylidene)-1,1,3,3-tetramethylindane with DMSO participation, affording access to one-sidedly overcrowded ketone and bromoalkene descendants§
Beilstein J. Org. Chem. 2014, 10, 307–315, doi:10.3762/bjoc.10.28
- ; DMSO; nucleophilic vinylic substitution; steric hindrance; Introduction The 1,1,3,3-tetramethylindan-2-yl(idene) fragments shown in the hydrocarbon parts of formulae 4–8 (Scheme 1) are preferable to the corresponding acyclic di-tert-butylmethylidene moiety (t-Bu2C in 1–3) as the shielding substituent
Chemistry of polyhalogenated nitrobutadienes, 10: Synthesis of highly functionalized heterocycles with a rigid 6-amino-3-azabicyclo[3.1.0]hexane moiety
Beilstein J. Org. Chem. 2012, 8, 621–628, doi:10.3762/bjoc.8.69
- ]hexane 1 in methanol at −40 °C, a twofold vinylic substitution led to the 4,4-bis(aminoazabicyclo[3.1.0]hexyl)-1-chloro-1,3-dinitrobutadiene 13 in 80% yield (Scheme 3). In an analogous treatment of the pentachloronitrobutadiene 3 with a fourfold excess of 1,2,4-triazole in diethyl ether the 4,4
Dioxane dibromide mediated bromination of substituted coumarins under solvent-free conditions
Beilstein J. Org. Chem. 2012, 8, 323–329, doi:10.3762/bjoc.8.35
- electron-donating group at C7, the heterocyclic ring in 1b and 1c underwent selective monobromination with an equimolar amount of DD through vinylic substitution of C3–H. In the 1H NMR spectra of 2b and 2c, the signal around δ 6.00 was absent and one singlet around δ 8.00 appeared due to olefinic hydrogen
- singlet at δ 6.29 due to the hydrogen at C3 of 1d was absent in 2d indicating vinylic substitution. In the 13C NMR spectrum a signal appeared at δ 151.0 due to the quaternary C carrying the bromine atom. When C4 and C7 were both substituted with an alkyl group and electron-donating group, respectively, as
- conclusively proved the presence of two bromine atoms in the product, which were due to electrophilic addition of bromine across the olefinic linkage without any vinylic substitution. 4-Methyl-7-(allyloxy)coumarin (1h) (Table 1, entry 9) underwent addition of bromine across the isolated double bond as well as
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