Bacterial degradation of the anti-depressant drug fluoxetine produces trifluoroacetic acid and fluoride ion

Amplification of a thermodynamically unfavoured macrocyclic product through the directed shift of the equilibrium between dynamic covalent chemistry library members is difficult to achieve. We show for the first time that during condensation of formaldehyde and cis-N,N'-cyclohexa-1,2-diylurea formation of inverted-cis-cyclohexanohemicucurbit[6]uril (i-cis-cycHC[6]) can be induced at the expense of thermodynamically favoured cis-cyclohexanohemicucurbit[6]uril (cis-cycHC[6]). The formation of i-cis-cycHC[6] is enhanced in low concentration of the templating chloride anion and suppressed in excess of this template. We found that reaction selectivity is governed by the solution-based template-aided dynamic combinatorial chemistry and continuous removal of the formed cycHC[6] macrocycles from the equilibrating solution by precipitation. Notably, the i-cis-cycHC[6] was isolated with 33% yield. Different binding affinities of three diastereomeric i-cis-, cis-cycHC[6] and their chiral isomer (R,R)-cycHC[6] for trifluoroacetic acid demonstrate the influence of macrocycle geometry on complex formation.

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Dentistry. Analysis of fluoride concentration in aqueous solutions by use of fluoride ion-selective electrode

10.3403/30298308 ◽

2018 ◽

Keyword(s):

Aqueous Solutions ◽

Fluoride Concentration ◽

Ion Selective Electrode ◽

Fluoride Ion ◽

Selective Electrode ◽

Fluoride Ion Selective Electrode

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Faculty Opinions recommendation of Crystal structures of a double-barrelled fluoride ion channel.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725773067.793516238 ◽

2016 ◽

Author(s):

Markus Seeger

Keyword(s):

Ion Channel ◽

Crystal Structures ◽

Fluoride Ion

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ipso-Nitration of Arylboronic Acids with Copper Nitrate and Trifluoroacetic Acid

Letters in Organic Chemistry ◽

10.2174/1570178615666180413122942 ◽

2018 ◽

Vol 15 (10) ◽

pp. 891-894 ◽

Cited By ~ 2

Author(s):

Zhu-Qing Wang ◽

Meng-Ping Guo ◽

Yong-Ju Wen ◽

Xiu-Li Shen ◽

Mei-Yun Lv ◽

...

Keyword(s):

Trifluoroacetic Acid ◽

Copper Nitrate ◽

Arylboronic Acids

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NMR spectroscopic investigation of p-substituted 2,4,4,6-tetraphenyl-1,4-dihydropyridines and their oxa and thia analogues

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19891854 ◽

1989 ◽

Vol 54 (7) ◽

pp. 1854-1869 ◽

Cited By ~ 16

Author(s):

Marián Schwarz ◽

Petr Trška ◽

Josef Kuthan

Keyword(s):

Nmr Spectroscopy ◽

Trifluoroacetic Acid ◽

Spectroscopic Investigation ◽

Nmr Spectra ◽

Dynamic Equilibrium

The 1H, 13C and 19F NMR spectra of photochromic p-substituted 2,4,4,6-tetraphenyl-1,4-dihydropyridines IIa-IIg, 1-methyl-2,4,4,6-tetraphenyl-1,4-dihydropyridines IIIa-IIIg, 2,4,4,6-tetraphenyl-4H-pyrans IVa-IVh, and 2,4,4,6-tetraphenyl-4H-thiopyran V were inspected; it was found that compounds IIa-IIg occur in a dynamic equilibrium with their dihydro tautomer VIa-VIg. Also deuteriodeprotonation of IIa and IIIa and their reaction with trifluoroacetic acid were investigated by NMR spectroscopy.

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Coupling of Steroid O-(Carboxymethyl)oxime Derivatives with Single-Protected α,ω-Diaminoalkanes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19992035 ◽

1999 ◽

Vol 64 (12) ◽

pp. 2035-2043 ◽

Cited By ~ 2

Author(s):

Vladimír Pouzar ◽

Ivan Černý ◽

Pavel Drašar

Keyword(s):

Trifluoroacetic Acid ◽

Protecting Groups ◽

Oxime Group ◽

Amino Groups ◽

New Approach ◽

Terminal Amino ◽

Oxime Derivatives

New approach to the synthesis of steroid oximes bearing O-substituents with terminal amino groups was described. The easily accessible steroid O-(carboxymethyl)oximes were reacted with single-protected Boc-α,ω-diaminoalkanes to give corresponding amide intermediates. From them the Boc protecting groups were cleaved with trifluoroacetic acid to afford the desired steroid derivatives with terminal amino groups. The procedure was succesfully tested on steroids with O-(carboxymethyl)oxime group in positions 7 and 17. The decomposition of target products was observed during deprotection of substituted 19-oximes.

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