Covalent fixation of boron in wood through transesterification with vinyl ester of carboxyphenylboronic acid

Abstract Vinyl ester of 4-carboxyphenylboronic acid has been synthesized and tested as reactive reagent for permanent fixation of boron in wood based on an improved approach described previously. The essence of the method is a covalent incorporation of the boron compound via transesterification between wood hydroxyl groups and vinyl ester containing boron. The synthesis of this vinyl ester was accomplished by exchange reaction of vinyl acetate with 4-carboxyphenylboronic acid. The obtained vinyl ester of carboxyphenylboronic acid was characterized by FTIR and 1H-, and 13C-NMR spectroscopy. The covalent fixation of boron to wood’s hydroxyl groups was achieved through potassium carbonate (K2CO3) catalyzed transesterification of the vinyl ester containing boron. The transesterification was confirmed by weight percentage gain (WPG) calculation, curcumin staining, FTIR, and 13C CP-MAS NMR spectroscopy. The efficiency of the reaction improved with increasing temperature and reaction time.

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A novel simple route to wood acetylation by transesterification with vinyl acetate

Holzforschung ◽

10.1515/hf.2007.026 ◽

2007 ◽

Vol 61 (2) ◽

pp. 143-147 ◽

Cited By ~ 28

Author(s):

Mohamed Jebrane ◽

Gilles Sèbe

Keyword(s):

Vinyl Acetate ◽

Classical Method ◽

Transesterification Reaction ◽

High Yield ◽

Hydroxyl Groups ◽

Weight Percentage ◽

Novel Method ◽

Increasing Temperature ◽

Cp Mas Nmr ◽

Weight Percentage Gain

Abstract A novel method for the acetylation of wood was investigated and compared with the classical method based on acetic anhydride. The transesterification reaction between vinyl acetate (VA) and hydroxyl groups of maritime pine sapwood (Pinus pinaster Soland) was performed in the presence of potassium carbonate as a catalyst and led to acetylated wood in high yield. The transesterification reaction was confirmed by FTIR and 13C CP-MAS NMR spectroscopy. The efficiency of the VA transesterification increased with increasing temperature, reaction time, and catalyst amount, but a significant weight percentage gain (WPG) was obtained after only 3 h at 90°C.

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Chemistry of chromotropic acid. 1H and 13C NMR spectroscopy of chromotropic acid and its derivatives

Canadian Journal of Chemistry ◽

10.1139/v91-180 ◽

1991 ◽

Vol 69 (8) ◽

pp. 1207-1211 ◽

Cited By ~ 3

Author(s):

Paris E. Georghiou ◽

Chi Keung (Jimmy) Ho ◽

Chester R. Jablonski

Keyword(s):

Nmr Spectroscopy ◽

13C Nmr ◽

Nmr Spectra ◽

Deuterium Oxide ◽

13C Nmr Spectroscopy ◽

Chromotropic Acid ◽

Hydroxyl Groups ◽

Two Dimensional ◽

1H And 13C Nmr ◽

C Nmr

The 1H and 13C NMR spectra of chromotropic acid (CTA) (4,5-dihydroxy-2,7-naphthalenedisulphonic acid) have been unambiguously assigned. Proton NOED spectra were used to show the proximity of both H-3 and H-6 and the hydroxyl groups. Two-dimensional 1H–13C NMR correlation spectra of CTA, of its corresponding diacetoxy derivative, and of 3-bromo- and 3,6-dibromo-CTA support the assignments. A regioselective deuterium exchange reaction of the C-3 and C-6 protons of CTA with deuterium oxide was observed during the NMR experiments. This latter finding is strongly indicative of the mode of formation, and of the nature of the chromogen formed in the reaction of CTA with formaldehyde in the well-known CTA-formaldehyde analytical reaction. Key words: chromotropic acid, 3-bromochromotropic acid, 3,6-dibromochromotropic acid.

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The Determination of Hydroxyl Groups in Coal by Fourier Transform Infrared and 13C NMR Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702834634785 ◽

1983 ◽

Vol 37 (6) ◽

pp. 497-502 ◽

Cited By ~ 32

Author(s):

R. W. Snyder ◽

P. C. Painter ◽

J. R. Havens ◽

J. L. Koenig

Keyword(s):

Fourier Transform ◽

Nmr Spectroscopy ◽

Fourier Transform Infrared ◽

13C Nmr Spectroscopy ◽

Hydroxyl Groups ◽

Oh Groups ◽

The Individual ◽

Oh Content ◽

C Nmr

Fourier transform infrared spectroscopy and solid state 13C NMR spectroscopy have been used to measure the hydroxyl groups in coal. The methodology depends upon measuring the intensities of bands and resonances assigned to the products of acetylation reactions. In the infrared three separate bands, assigned to acetylated phenolic OH, alkyl OH, and NH groups, can be identified. In NMR, we used the methoxy carbon to determine the total OH. Spectroscopic measurements demonstrate that not only does the total OH content of coals but also the individual types of OH groups vary systematically as a function of rank. The proportion of phenolic to alkyl OH is approximately constant for the coals used in this study.

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The mechanism of formation of 2,7-dimethyl-2,6-octadiene in the synthesis of 3-methylene-7-methyl-1,6-octadiene

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19831864 ◽

1983 ◽

Vol 48 (7) ◽

pp. 1864-1866

Author(s):

Jan Bartoň ◽

Ivan Kmínek

Keyword(s):

Mass Spectrometry ◽

Nmr Spectroscopy ◽

Alkali Metal ◽

Chromatographic Analysis ◽

Solid Phase ◽

Reaction Pathway ◽

Mechanism Of Formation ◽

Gas Chromatographic Analysis ◽

C Nmr ◽

Visual Observations

2,7-Dimethyl-2,6-octadiene is formed in the catalytic solution for the dimerization of 2-methyl-1,3-butadiene to β-myrcene (3-methylene-7-methyl-1,6-octadiene), as revealed by mass spectrometry and 13C NMR spectroscopy. Visual observations together with the results of gas chromatographic analysis of the catalytic solution suggest that the formation of 2,7-dimethyl-2,6-octadiene is associated with the transition of the alkali metal (sodium) from the solid phase into the solution. A reaction pathway is suggested accounting for the formation of 2,7-dimethyl-2,6-octadiene in the system.

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Non-cyclol (lactame) ergot alkaloids

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19823312 ◽

1982 ◽

Vol 47 (12) ◽

pp. 3312-3317 ◽

Cited By ~ 6

Author(s):

Josef Stuchlík ◽

Alois Krajíček ◽

Ladislav Cvak ◽

Jiří Spáčil ◽

Petr Sedmera ◽

...

Keyword(s):

Nmr Spectroscopy ◽

Ergot Alkaloids ◽

C Nmr

Two new alkaloids were isolated from the field ergot. Their structures, N-(D-lysergyl-L-valyl)cyclo(L-valyl-D-prolyl) (IV) and N-(D-lysergyl-L-valyl)cyclo(L-leucyl-D-prolyl) (V), were assigned by mass, 1H and 13C NMR spectroscopy.

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An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19912917 ◽

1991 ◽

Vol 56 (12) ◽

pp. 2917-2935 ◽

Cited By ~ 1

Author(s):

Eva Klinotová ◽

Václav Křeček ◽

Jiří Klinot ◽

Miloš Buděšínský ◽

Jaroslav Podlaha ◽

...

Keyword(s):

Acetic Acid ◽

Nmr Spectroscopy ◽

Acetic Anhydride ◽

Spectral Methods ◽

X Ray Diffraction ◽

X Ray ◽

Mild Conditions ◽

Condensation Products ◽

Unsaturated Lactones ◽

C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

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A New Dimeric Derivative of Ethoxyquin from Its Reaction with Alkylperoxy Radicals

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19931914 ◽

1993 ◽

Vol 58 (8) ◽

pp. 1914-1918 ◽

Cited By ~ 3

Author(s):

Jaroslav Kříž ◽

Luděk Taimr

Keyword(s):

Mass Spectrometry ◽

Nmr Spectroscopy ◽

Peroxy Radicals ◽

Methyl Group ◽

Alkylperoxy Radicals ◽

C Nmr

The structure of a new compound formed in the reaction of ethoxyquin with alkylperoxy radicals was resolved by 1H and 13C NMR spectroscopy (including COSY, NOESY, HHC RCT and SSLR INEPT techniques) and confirmed by mass spectrometry. The structure suggest participation of 4-methyl group of ethoxyquin in the deactivation of peroxy radicals. A mechanism of this reaction is proposed.

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Reactivity of Sodium Hexaethyl-2,4-dicarba-nido-hexaborate(1-)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19990977 ◽

1999 ◽

Vol 64 (6) ◽

pp. 977-985 ◽

Cited By ~ 17

Author(s):

Bernd Wrackmeyer ◽

Hans-Jörg Schanz ◽

Wolfgang Milius ◽

Catherine McCammon

Keyword(s):

Mössbauer Spectroscopy ◽

Nmr Spectroscopy ◽

Structural Analysis ◽

Hydrogen Atom ◽

Mossbauer Spectroscopy ◽

Sandwich Complex ◽

X Ray ◽

Bromo Derivative ◽

Boron Tribromide ◽

C Nmr

Sodium hexaethyl-2,4-dicarba-nido-hexaborate(1-) (6), available from hexaethyl-2,4-dicarba- nido-hexaborane(8) (4) by deprotonation, reacts with deuterated methanol, CD3OD, to give back 4 without H/D exchange of the B-H-B hydrogen atom. The reaction of 6 with diethylboron chloride, Et2BCl, affords hexaethyl-2,4-dicarba-closo-hexaborane(6) (7), the first example of a peralkylated carborane of this type. In contrast, the reaction of 6 with boron tribromide, BBr3, leads mainly to 2,3,4,5,6,7-hexaethyl-2,4-dicarba-closo-heptaborane(7) (8), together with the corresponding 1-bromo derivative (9) and the closo-carborane 7 as side products. The reaction of two equivalents of 6 with FeCl2 gives the air-stable sandwich complex bis[hexaethyl-2,4-dicarba-nido-hexaborate(1-)]iron 10 which was characterised by X-ray structural analysis. All products were characterised by 1H, 11B and 13C NMR spectroscopy, and 57Fe Mössbauer spectroscopy was used to study 10.

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Formation of spiro adduct from N-methyl-N-(2,4,6-trinitrophenyl)glycine anion

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19890440 ◽

1989 ◽

Vol 54 (2) ◽

pp. 440-445 ◽

Cited By ~ 1

Author(s):

Vladimír Macháček ◽

Alexandr Čegan ◽

Miloš Sedlák ◽

Vojeslav Štěrba

Keyword(s):

Nmr Spectroscopy ◽

Dimethyl Sulfoxide ◽

Equilibrium Constant ◽

Mole Fraction ◽

Nucleophilic Addition ◽

Adduct Formation ◽

First Case ◽

C Nmr

The intramolecular nucleophilic addition of N-methyl-N-(2,4,6-trinitrophenyl)glycine anion in methanol-dimethyl sulfoxide mixtures produces spiro[(3-methyl-5-oxazolidinone)-2,1'-(2',4',6'-trinitrobenzenide)]. The spiro adduct has been identified by means of 1H and 13C NMR spectroscopy. This is the first case when the formation of a Meisenheimer adduct with carboxylate ion is observed. Logarithm of the equilibrium constant of adduct formation increases linearly with the mole fraction of dimethyl sulfoxide in its mixture with methanol.

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