109317-74-0Relevant articles and documents
Addition-Elimination Reaction in the Trifluoroacetylation of Electron-Rich Olefins
Moriguchi, Takeshi,Endo, Takeshi,Takata, Toshikazu
, p. 3523 - 3528 (1995)
Reactions of electron-rich olefins such as vinyl ether 1 and vinyl sulfide 2 with trifluoroacetic anhydride in carbon tetrachloride at room temperature proceeded by the formation of addition products 7 and 8, respectively, which were identified as stable intermediates by 1H NMR and IR spectra, eventually giving the corresponding trifluoroacetylated olefins 5 and 6 as substitution products.These reactions were also observed in chloroform and dichloromethane in the absence of base, such as pyridine.These results supported the addition-elimination mechanism.The processes of the addition and elimination were confirmed by the 1H NMR spectrum and kinetic study which led to the following results: The addition products 7 and 8 were formed through a stepwise trans addition, and the trifluoroacetylated olefins 5 and 6 were self-catalytically formed from the addition products 7 and 8 through Ei, E2, or E1, depending on the stability of the cationic intermediates 3 and 4.
Unsaturated nitrogen compounds containing fluorine. Part 19. Cycloaddition reactions of 2,5-dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene with cycloalkenes and cyclodienes
Abdul-Ghani, Mohammad M.,Tipping, Anthony E.
, p. 189 - 202 (1995)
Thermal reaction (20-70 deg C) of the dichloroazine CF3CCl=NN=CClCF3, 2, with cyclopentene (in CH2Cl2 solvent), cycloheptene, indene, acenaphthylene, 2,3-dihydrofuran, 3,4-dihydro-2H-pyran, norbornadiene and dicyclopentadiene afforded, as the major product in each case, the corresponding rearranged cycloadduct 3 containing a grouping.The direction of cycloaddition to the unsymmetrical carbocycles indene and cyclopentadiene was consistent with the reactions being LUMO (azine)-HOMO (dipolarophile) controlled.On attempted chromatographic purification on silica gel, the rearranged adducts 3 were hydrolysed to the corresponding amides 4 (-->).The cyclopentene reaction, unexpectedly, also gave the cyclopentadiene cycloadduct 3b, while from the norbornadiene reaction a hydrolysed 2:1 adduct 9 (4percent) was isolated by chromatography.Other products obtained by chromatographic separation from the 3,4-dihydro-2H-pyran reaction were the substituted azine (5) (29percent), equimolar amounts of the ketone (6) (18percent) and the chlorohydrazone (7) (18percent), possibly arising via the cycloadduct 15 of 5 and the pyran, and the hydrazone (8) (4percent), formed via 15 or by hydrolysis of the amide 4g.Treatment of amide 4d, derived from indene with ethanolic methylamine, gave the expected amino compound 21a (94percent) and CF3CONHMe (22) (91percent).In contrast, treatment of the exo-amide 4h, derived from norbornadiene with ethanolic methylamine, afforded the N-formyl compound 23 (87percent), while corresponding treatment of a mixture of the exo- and endo-amides (4h and 4i) gave the exo- and endo-amino compounds (21b and 21c) (88percent), together with compound 22 (ca. 10percent) and the azapropenylindazole 24 (ca. 5percent); compound 24 hydrolysed to 23 on storage.It is proposed that the amines 21b and 21c arose mainly via the sequence: --> (24)--> (23)-->. - Keywords: Unsaturated nitrogen compounds; Cycloaddition reactions; Dichlorohexafluorodiazahexadiene; NMR spectroscopy; IR spectroscopy; Mass spectrometry
Synthesis of trifluoromethyl-substituted 1,2,6-thiadiazine 1-oxides from sulfonimidamides under mechanochemical conditions
Bolm, Carsten,Julian Lentelink, Niklas,Rissanen, Kari,Sch?bel, Jan-Hendrik,Thomas Passia, Marco,Truong, Khai-Nghi
supporting information, p. 9470 - 9475 (2021/11/17)
TBS-protected or NH-sulfonimidamides react with β-alkoxyvinyl trifluoromethylketones under solvent-free mechanochemical conditions to give 3-trifluoromethyl-substituted three-dimensional 1,2,6-thiadiazine 1-oxides. C4-Functionalized products can be obtained by starting from cyclic enones and brominations of the initially formed heterocycles. The stability of the products was investigated by varying the pH value and storage under aerobic conditions. This journal is
Synthesis of a series of trifluoromethylazoles and determination of pKa of acidic and basic trifluoromethyl heterocycles by 19F NMR spectroscopy
Jones, Brian G.,Branch, Sarah K.,Thompson, Andrew S.,Threadgill, Michael D.
, p. 2685 - 2692 (2007/10/03)
Trifluoroacetylation at the 5-position of 3,4-dihydro-2H-pyran and the 3-position of 4,5-dihydrofuran, followed by treatment with hydrazine, gave 3-(3-trifluoromethyl-1H-pyrazol-4-yl)propanol and 2-(3-trifluoromethyl-1H-pyrazol-4-yl)ethanol, respectively.In the latter case, an intermediate dimer was isolated.Isomeric 2-(3-trifluoromethyl-1H-pyrazol-5-yl)ethanol was formed by reaction of hydrazine with 6-benzyloxy-1,1,1-trifluorohex-3-yn-2-one and deprotection.Reaction of 3-benzyloxypropylamine with 2,5-bis(trifluoromethyl)-1,3,4-oxadiazole, followed by deprotection, afforded 3-propanol.A series of 2-trifluoromethyl-1H-benzimidazoles and 2-trifluoromethyl-3H-imidazopyridines were prepared by condensation of the appropriate ortho-arenediamine with trifluoroacetic acid.Analysis of the 19F NMR spectra of the trifluoromethylazoles and of 3-trifluoromethylpyridine in aqueous solution at different pHs enabled determination of pKa values.All the compounds evaluated had one or more pKa between 1 and 13, except the triazole.Several compounds were identified as having potential use in measuring pH in biological media by 19F NMR spectroscopy.
Novel cycloaddition products from the reaction of 2,5-dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene with cycloalkenes, cyclodienes and cycloheptatriene, and of hexafluoroacetone azine with cycloheptatriene
Abdul-Ghani, Mohamad,Tipping, Anthony E.
, p. 5 - 11 (2007/10/02)
Thermal reaction (20-70 deg C) of the dichloroazine CF3CCI=N-N=CCICF3 (2) with cyclopentene (in CH2CI2 solwent), cycloheptene, indene, acenaphtylene, 2,3-dihydrufuran, 2,3-dihydropyran, norbornadiene, cyclopentadiene and dicyclopentadiene gives as the major product in each case the rearranged cycloadduct (3) containing a CF3CCI2 group; hydrolisys (CF3CCI2 --> CF3CO) to give the amide (4) takes place on attempted chromatographic purification on silica gel.With cyclopentene the rearrangad cyclopentadiene cycloadduct (3b) is also formed, while other products obtained by chromatographic separation from the 2,3-dihydropylan reaction are the 5,6-dihydropyran-3-yl azine (5), the hydrozone (8) and equimolar quantities of 5,6-dihydropyran-3-yl trifluoromethyl ketone (6) and the chlorohydrazone (7) possible arising via hydrolysis of the 1:2 adduct (16).The reaction of azine 2 with cycloheptatriene at 70 deg C gives a complex mixture, in which the major products are the rearranged cycloadduct (31) and the dehydrochlorinated cycloadduct (10) and (11) containing a CF3CHCI group.The corresponding reaction with hexafluoroacetone azine (1) at 70 deg C affords the criss-cross cycloadduct (22), the bis-ene adduct (23) and its oxidation product, the azo compound (24), and the cycloadduct diaziridine (25).
Trihaloacetylated enol ethers - General synthetic procedure and heterocyclic ring closure reactions with hydroxylamine
Colla,Martins,Clar,Krimmer,Fischer
, p. 483 - 486 (2007/10/02)
An improved procedure is described for preparing β-trichloro- and β-trifluoroacetyl derivatives of six simple enol ethers, in analytically pure form, high yield, and on an up to molar scale. The 4-alkoxy-1,1,1-trichloro[fluoro]-3-alken-2-ones 4a-c and 5a-c, thus obtained, are cyclocondensed with hydroxylamine hydrochloride (in pyridine, 35°C) to afford the 5-hydroxy-5-trichloro[fluoro]methyl-4,5-dihydroisoxazoles 6 and 7 in high yield. With cyclic substrates, i.e. the trihaloacetyl dihydrofurans and -2H-pyrans 4d, e and 5d, e, a competitive rearrangement reaction gives 3-cyano-2-hydroxy-2-trichloro[fluoro]methyltetrahydrofurans and -2H-pyrans 8 and 9, respectively. Direct condensation to a dihydroisoxazole prevails at 0°C (>85% for 4d, 5d), rearrangement to the cyano compounds at higher temperatures (65-70°C, > 70%). Under either condition, the respective heterocycle may be isolated in > 60% yield (except for 6e).
A Convenient Synthetic Method for β-Alkoxy- and β-Phenoxyacrylic Acids and 3,4-Dihydro-2H-pyran-5- and 2,3-Dihydrofuran-4-carboxylic Acids
Hojo, Masaru,Masuda, Ryoichi,Sakaguchi, Syuhei,Takagawa, Makoto
, p. 1016 - 1017 (2007/10/02)
trans-β-Trihaloacetylvinyl ethers 1 are easily hydrolyzed by wet potassium hydroxide in benzene, yielding the corresponding acids 2 in excellent yields.This synthetic method also can be applicable to cyclic vinyl ethers 3 and 5 to yield 4 and 6 in high yi
