Preparation and NMR studies of 3-selenaheptadecanoic and 4-selenaoctadecanoic acid, RSe(CH2)nC(O)OH (R = C14H29, n = 1 and 2), and their methyl esters

Doudin, Khalid; Berge, Rolf K.; Frøystein, Nils Åge; Songstad, Jon

doi:10.1039/a909142d

Cited by 9 publications

(3 citation statements)

References 22 publications

(40 reference statements)

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“…8 Proton decoupled 77 Se NMR spectra were recorded on a Bruker DRX-600 Fourier transform NMR spectrometer operating at 114.4 MHz. Typical conditions were sweep width 45 871 Hz, pulse width 8.1 µs (¾90°flip angle), acquisition time 0.71 s, recycling delay 2 s, 32 768 time domain points and 128 scans.…”

Section: Methodsmentioning

confidence: 99%

“…This selenide, which is not commercially available, is readily prepared in high yield from the fairly cheap 1-bromotetradecane, C 14 H 29 Br, and is easily purified by crystallization from diethyl ether. 8 The compound, with a melting-point of 48°C, is a nonodorous and colourless compound which is stable for long periods, particularly when direct sunlight is avoided, and can be handled without any particular precautions. This selenide is sufficiently soluble in most organic solvents at room temperature, e.g.…”

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Ditetradecyl selenide, (C14H29)2Se, a new chemical shift reference compound for77Se NMR

2000

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Ditetradecyl selenide, (C14H29)2Se, is suggested as an alternative to Me2Se as a reference compound for 77Se NMR in organic solvents. This selenide, a crystalline, non‐odorous and stable compound, is readily prepared and purified and is sufficiently soluble in most of the usual organic solvents at room temperature to give a satisfactory 77Se signal; in methanol, acetonitrile and dimethyl sulfoxide temperatures above ∼310 K are required. The chemical shifts, +162.3 ppm in CDCl3 at 298 K relative to a 60% solution of Me2Se in CDCl3, defined as 0.0 ppm, and +167.2 ppm relative to a 0.25 M solution of Me2Se in CDCl3, is independent of the concentration in the 0.01–0.40 M range. The shift in CDCl3 increases fairly linearly with temperature in the 270–345 K range with a slope of ∼0.075 ppm K−1. The shift appears to be less dependent upon the solvent than the shift of Me2Se. Copyright © 2000 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 99%

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Ditetradecyl selenide, (C14H29)2Se, a new chemical shift reference compound for77Se NMR

2000

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“…It is notable that the signal due to the 3-CH 2 protons is some 0.5 ppm downfield from that of the 2-CH 2 protons. For several alkyl-substituted seleno-propanoic acids, RSeCH 2 CH 2 COOH [11,12], and Se(CH 2 CH 2 COOH) 2 [8] the 1 H NMR signals due to these CH 2 groups are most difficult to separate. The distinct separation, ~ 0.5 ppm, is probably due to a significant selenonium character of the Se-betaine.…”

Section: Synthesis and Analysismentioning

confidence: 99%

Selenium carboxylic acids betaine; 3,3′,3″-selenotris(propanoic acid) betaine, Se(CH 2 CH 2 COOH) 2 (CH 2 CH 2 COO)

Doudin

Törnroos

2017

Journal of Molecular Structure

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Attempts to prepare [Se(CH 2 CH 2 COOH) 3 ] + Clfrom Se(CH 2 CH 2 COOH) 2 and H 2 C=CHCOOH in concentrated hydrochloric acid, for the corresponding sulfonium salt, led exclusively to the Se-betaine, Se(CH 2 CH 2 COOH) 2 (CH 2 CH 2 COO). The Se-betaine crystallises in the space group P2 l /c with the cell dimensions at 223 K, a = 5.5717(1), b = 24.6358(4), c = 8.4361(1) Å, β = 104.762(1)°, V = 1119.74(3) Å 3 , Z = 4, D calc = 1.763 Mgm-3 , µ = 3.364 Mm-1. The structure refined to R I = 0.0223 for 2801 reflections with F o > 4σ(F o). In the crystalline state the molecule is intermolecularly linked to neighbouring molecules by a number of hydrogen bonds; a very strong carboxylic-carboxylate bond with an O••••O distance of 2.4435(16) Å, a medium strong carboxylic-carboxylate bond with an O••••O distance of 2.6431(16) Å and several weak O••••H(CH 2) with O••••C distances between 3.2 and 3.3 Å. In the carboxylic group involved in the very strong hydrogen bond the O••••H bond is antiperiplanar to the C=O bond while the O-H bond is periplanar to the C=O bond in the second carboxylic group. Based upon the CO bond lengths and the elongation of the O-H bond involved in the strong hydrogen bond one may describe the compound as strongly linked units of Se(CH 2 CH 2 COOH)(CH 2 CH 2 COO) 2 rather than Se(CH 2 CH 2 COOH) 2 (CH 2 CH 2 COO). The selenium atom forms two strong intramolecular 1,5-Se••••O contacts, with a carboxylate oxygen atom, 2.9385(12) Å, and with a carboxylic oxygen atom, 2.8979(11) Å. To allow for these contacts the two organic fragments have been forced into the periplanar conformation. The molecule is only slightly asymmetric with regard to the C-Se-C bond angles but is very asymmetric with regard to the torsion angles.

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Synthesis of Biologically Relevant Small Molecules Containing Selenium. Part A. Antioxidant Compounds

Braga

Rafique

2013

Patai's Chemistry of Functional Groups

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The design and synthesis of organoselenium compound as bioactive structures have achieved a new dimension since the 1970s, when many reports described the identification of various selenoproteins, which are involved in a wide variety of biological processes, including antioxidant defense, thyroid hormone production and immune response. In this chapter, strategies and methods for the preparation of synthetic antioxidants containing selenium are reviewed. The unique redox properties of selenium confer catalytic activity to organoselenium compounds and influence their biological properties as well as the methods selected for their preparation. Several approaches can be applied in order to obtain organoselenium compounds, such as reaction of elemental selenium or diselenides with different types of carbanions or reaction of organic electrophiles with selenolate anions generated by different methods, as discussed herein.

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Preparation and NMR studies of 3-selenaheptadecanoic and 4-selenaoctadecanoic acid, RSe(CH2)nC(O)OH (R = C14H29, n = 1 and 2), and their methyl esters

Cited by 9 publications

References 22 publications

Ditetradecyl selenide, (C14H29)2Se, a new chemical shift reference compound for77Se NMR

Ditetradecyl selenide, (C14H29)2Se, a new chemical shift reference compound for77Se NMR

Selenium carboxylic acids betaine; 3,3′,3″-selenotris(propanoic acid) betaine, Se(CH 2 CH 2 COOH) 2 (CH 2 CH 2 COO)

Synthesis of Biologically Relevant Small Molecules Containing Selenium. Part A. Antioxidant Compounds

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