The Action of Trifluoromethanesulfonic Acid on Naphthalene

1993 ◽  
Vol 46 (4) ◽  
pp. 427 ◽  
Author(s):  
A Launikonis ◽  
WHF Sasse ◽  
IR Willing

Trifluoromethanesulfonic ( triflic ) acid reacts with naphthalene at room temperature to give a complex mixture from which five products have been isolated and identified as follows: (E)-3-benzylidene-2,3-dihydro-1H-benz[e]indene (2) (yield 15-20%), 1,2,3,4-tetrahydroanthracene (7) (c. 0.5%), 4-phenyl-1,2-dihydroanthracene (8), 3,4-dihydro-1,2′-binaphthyl (9a′), 4-(2-naphthyl)-1,2-dihydroanthracene (10) [yields of (8), (9a′) and (10) each less than 0.1%]. Also formed is (Z)-2-benzylidene-1,3-dihydro-1H-benz[e]indene (6) which is formed reversibly from (2) by the action of triflic acid. Mechanisms are proposed for the formation of these products.

2016 ◽  
Vol 12 ◽  
pp. 2125-2135 ◽  
Author(s):  
Dmitry S Ryabukhin ◽  
Dmitry N Zakusilo ◽  
Mikhail O Kompanets ◽  
Anton A.Tarakanov ◽  
Irina A Boyarskaya ◽  
...  

The reaction of 5-hydroxymethylfurfural (5-HMF) with arenes in superacidic trifluoromethanesulfonic acid (triflic acid, TfOH) as the solvent at room temperature for 1–24 h gives rise to 5-arylmethylfurfurals (yields of 17–91%) and 2-arylmethyl-5-(diarylmethyl)furans (yields of 10–37%). The formation of these two types of reaction products depends on the nucleophilicity of the arene. The same reactions under the action of acidic zeolites H-USY in high pressure tubes at 130 °C for 1 h result in the formation of only 5-arylmethylfurfurals (yields of 45–79%). 2,5-Diformylfuran (2,5-DFF) in the reaction with arenes under the action of AlBr3 at room temperature for 1 h leads to 5-(diarylmethyl)furfurals (yields of 51–90%). The reactive protonated species of 5-HMF and 2,5-DFF were characterized by NMR spectroscopy in TfOH and studied by DFT calculations. These reactions show possibilities of organic synthesis based on biomass-derived 5-HMF and 2,5-DFF.


2011 ◽  
Vol 76 (4) ◽  
pp. 591-606 ◽  
Author(s):  
Mihail Ionescu ◽  
Zoran Petrovic

Novel bio-based compounds containing phenols suitable for the synthesis of polyurethanes were prepared. The direct alkylation of phenols with different vegetable oils in the presence of superacids (HBF4, triflic acid) as catalysts was studied. The reaction kinetics was followed by monitoring the decrease of the double bond content (iodine value) with time. In order to understand the mechanism of the reaction, phenol was alkylated with model compounds. The model compounds containing one internal double bond were 9-octadecene and methyl oleate and those with three double bonds were triolein and high oleic safflower oil (82% oleic acid). It was shown that the best structures for phenol alkylation are fatty acids with only one double bond (oleic acid). Fatty acids with two double bonds (linoleic acid) and three double bonds (linolenic acid) lead to polymerized oils by a Diels Alder reaction, and to a lesser extent to phenol alkylated products. The reaction product of direct alkylation of phenol with vegetable oils is a complex mixture of phenol alkylated with polymerized oil (30-60%), phenyl esters formed by transesterification of phenol with triglyceride ester bonds (<10 %) and unreacted oil (30%). The phenolated vegetable oils are new aromatic-aliphatic bio-based raw materials suitable for the preparation of polyols (by propoxylation, ethoxylation, Mannich reactions) for the preparation of polyurethanes, as intermediates for phenolic resins or as bio-based antioxidants.


2021 ◽  
Author(s):  
Andrey I Puzanov ◽  
Dmitry S Ryabukhin ◽  
Anna S Zalivatskaya ◽  
Dmitriy N Zakusilo ◽  
Darya S Mikson ◽  
...  

Acetylene derivatives of 1,2,4-oxadiazoles, 5-(2-arylethynyl)-3-aryl-1,2,4-oxadiazoles, have been obtained, for the first time, from 5-(2-arylethenyl)-3-aryl-1,2,4-oxadiazoles by their bromination at the carbon-carbon double bond followed by di-dehydrobromination with NaNH2 in liquid NH3.  Reaction of the acetylene 1,2,4-oxadiazoles with arenes in neat triflic acid TfOH (CF3SO3H) at room temperature for 1 h result in the formation of E-/Z-5-(2,2-diarylethenyl)-3-aryl-1,2,4-oxadiazoles as products of regioselective hydroarylation of the acetylene bond. Addition of TfOH to acetylene bond of these oxadiazoles gives rise quantitatively to E-/Z-vinyl triflates. Reaction cationic intermediates have been studied by DFT calculations. The reaction mechanisms have been discussed.


2021 ◽  
Vol 8 ◽  
Author(s):  
Fa-Jie Chen ◽  
Zhenguo Hua ◽  
Jianhui Chen ◽  
Jiajia Chen ◽  
Daesung Lee ◽  
...  

Herein, we report an efficient method for the synthesis of (Z)-β-halovinyl ketones through a one-pot Sonogashira coupling and hydrohalogenation reaction promoted by palladium-copper catalyst and Brønsted acid. The ynone intermediates are generated in situ from readily available acid chlorides and terminal alkynes at room temperature, which are directly converted to (Z)-β-halovinyl ketones by treating with triflic acid. This method avoids the use of an external halogen source and features broad substrate scope, high yield, and good to excellent stereoselectivity.


1979 ◽  
Vol 32 (4) ◽  
pp. 737 ◽  
Author(s):  
GB Deacon ◽  
D Tunaley

Thallic trifluoromethanesulfonate has been prepared by reaction of trifluoromethanesulfonic acid with either thallic oxide or solutions of thallic trifluoroacetate in trifluoroacetic acid, and has been isolated as the trihydrate on crystallization fromnitromethane. The polyfluoroarenes,p-CH3OC6F4H, p-CH3C6F4H, m-H2C6F4, o-H2C6F4, p-H2C6F4, C6F5H, 1,3,5-F3C6H3 or 1,2,4-F3C6H3, have been thallated by thallic trifluoromethanesulfonate in trifluoroacetic acid, giving the corresponding poly- fluorophenylthallium(III) bis(trifluoromethanesulfonates), which have been characterized spectroscopically and by conversion into the corresponding (polyfluoro)iodobenzenes on treatment with sodium iodide. Only slight thallation of m-BrC6F4H and m-O2NC6F4H was observed. By contrast with thallic trifluoromethanesulfonate, thallic trifluoroacetate in trifluoroacetic acid induced little thallation of the most reactive polyfluorobenzene, p-CH3OC6F4H. Thallic trifluoromethanesulfonate also thallated p-CH3OC6F4H in nitromethane, sulfolane, and with the substrate as solvent, but p-CH3C6F4H failed to react. Treatment of the polyfluorophenylthallium(III) bis(trifluoromethane- sulfonates) with boiling aqueous sodium acetate caused symmetrization into the corresponding acetatobis(polyfluorophenyl)thallium(III) compounds. A similar reaction between 2,4,6-trifluoro- phenylthallium(III) bis(trifluoromethanesulfonate) and sodium acetate at room temperature yielded 2,4,6-trifluorophenylthallium(III) diacetate. 2,3,4,6-Tetrafluorophenylthallium(III) bis(trifluor0- methanesulfonate) was converted by boiling water into bis(2,3,4,6-tetrafluorophenyl)thallium(III) trifluoromethanesulfonate.


2008 ◽  
Vol 73 (12) ◽  
pp. 1729-1746 ◽  
Author(s):  
Dorota Grzybowska ◽  
Przemysław Malinowski ◽  
Zoran Mazej ◽  
Wojciech Grochala

The reactivity of Ag(II)F2 towards a variety of organic compounds of a high degree of fluorination has been investigated. AgF2 readily fluorinates P(C6F5)3 to PF2(C6F5)3, and attacks the isothiocyanate functional group, -NCS, yielding Ag2S. Perfluorinated aliphatic nitriles resist the action of AgF2, but aromatic C6F5CN undergoes a radical-initiated oligomerization; byproducts include C6F6CN• and C6F5N2• (after intramolecular rearrangement following the bimolecular reaction). AgF2 oxidizes higher fluorosulfonic acids (C4F9SO3H, C8F17SO3H) at or close to the room temperature and triflic acid (CF3SO3H) at its boiling point to the corresponding peroxides. CF3COOH and CF3CONH2 are also decomposed in redox reactions, but the gaseous products have not been identified. Surprisingly, AgF2 is kinetically inert to perfluorinated aromatic hydrocarbons and to CCl4, but it decomposes CBr4 with vigorous elimination of Br2. CI4 decomposes explosively in the presence of AgF2. C6F5OH and CF3COOH are readily oxidized with AgF2 but, surprisingly, t-C4F9OH is kinetically resistant under similar conditions. Coordination complexes of perfluorinated aza and oxa Lewis bases (including perfluorinated 15-crown-5 ether) and AgF2 are not formed under the experimental conditions.


2006 ◽  
Vol 62 (2) ◽  
pp. 173-189 ◽  
Author(s):  
E. G. Moshopoulou ◽  
R. M. Ibberson ◽  
J. L. Sarrao ◽  
J. D. Thompson ◽  
Z. Fisk

The room-temperature crystal structure of the heavy fermion antiferromagnet Ce2RhIn8, dicerium rhodium octaindide, has been studied by a combination of high-resolution synchrotron X-ray reciprocal-space mapping of single crystals and high-resolution time-of-flight neutron powder diffraction. The structure is disordered, exhibiting a complex interplay of non-periodic, partially correlated planar defects, coexistence and segregation of polytypic phases (induced by periodic planar `defects'), mosaicity (i.e. domain misalignment) and non-uniform strain. These effects evolve as a function of temperature in a complicated way, but they remain down to low temperatures. The room-temperature diffraction data are best represented by a complex mixture of two polytypic phases, which are affected by non-periodic, partially correlated planar defects, differ slightly in their tetragonal structures, and exhibit different mosaicities and strain values. Therefore, Ce2RhIn8 approaches the paracrystalline state, rather than the classic crystalline state and thus several of the concepts of conventional single-crystal crystallography are inapplicable. The structural results are discussed in the context of the role of disorder in the heavy-fermion state and in the interplay between superconductivity and magnetism.


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