[2+2] Cycloaddition and electrophilic alkynylation reactions of 4-chloro-1,1,1-trifluorobut-3-yn-2-one and alkyl vinyl ethers

Reaction of 4-chloro-1,1,1-trifluorobut-3-yn-2-one with alkyl vinyl ethers leads to the parallel formation of [2+2] cycloaddition and electrophilic alkynylation products, the ratio of which depends on the nature of vinyl ether. Preparative methods for the separation of compounds formed are suggested.     

Product of uncommon reaction of 1,1,1-trifluoro-4-phenylbut-3-yn-2-one with diphenyldiazomethane

Russian Journal of Organic Chemistry - 1,1,1-Trifluoro-4-phenylbut-3-yn-2-one reacts with diphenyldiazomethane at 20°С in ethyl ether to afford...     

4-Halogeno-1,1,1-trifluorobut-3-yn-2-one [4+2] cycloadducts and their cross-coupling with organozinc compounds

The reactions of 4-chloro-1,1,1-trifluorobut-3-yn-2-one and 4-bromo-1,1,1-trifluorobut-3-yn-2-one with conjugated dienes afford [4+2] cycloadducts in high yields. The halogen atom in the products is readily replaced by a (het)aryl residue in the cross-coupling with organozinc compounds.     

Light-induced reactions of 1,1,1-trifluoro-3-decyn-2-one with olefins

Irradiation ( λ = 300 nm) of 1,1,1-trifluoro-3-decyn-2-one in the presence of olefins affords RH-reduction products (tertiary alcohols) in addition to [2+2] -(oxetans) and [3+2] -(dihydrofurans) cycloadducts.     

Synthesis Of CF3-Heterocycles Based on 4-Dimethylamino-1,1,1-trifluoro-3-buten-2-one

Novel heterocyclizations have been investigated based on the reaction of the complex between trifluoromethanesulfonic anhydride and 4-dimethylamino-1,1,1-trifluoro-3-buten-2-one with 2,2'-biindolyl and N,N'-dipyrrolylmethane leading to closure of 6- or 7-membered rings.     

Reactions of tri- and hexafluoroacetylacetones and 4-ethoxy-1,1,1-trifluorobut-3-en-2-one with 2-aminobenzohydrazide

Reactions of 1,1,1-trifluoropentane-2,4-dione and 1,1,1,5,5,5-hexafluoropentane-2,4-dione with 2-aminobenzohydrazide afforded (2-aminophenyl)[5-hydroxy-3-methyl-5-(trifluoromethyl)- and (2-aminophenyl)[ 5-hydroxy-3,5-bis(trifluoromethyl)-4,5-dihydropyrazol-1-yl]methanones, respectively. 4-Ethoxy-1,1,1- trifluorobut-3-en-2-one reacted with 2-aminobenzhydrazide to give 2-(trifluoromethyl)-3a,4-dihydropyrazolo-[5,1-{ptb}]quinazolin-9(3{ptH})-one.     

Synthesis and reactions of (E)-1,1,1-trifluoro-2-methyl-2-penten-4-ylidene-malonodinitrile

Condensation of (E)-1,1,1-trifluoro-2-methyl-2-penten-4-one with malonodinitrile affords mixtures of unsaturated nitriles. Attempted cyclization of these nitriles in concentrated sulfuric acid furnishes derivatives of alkylidenecyanoacetamides and alkylidenemalonodiamide.     

LDA-mediated domino carbolithiation reactions of vinylidenecyclopropanes with but-3-yn-2-one and 1-phenylprop-2-yn-1-one

A novel domino carbolithiation reaction of vinylidenecyclopropanes 1 with but-3-yn-2-one and 1-phenylprop-2-yn-1-one by treating with LDA in THF was observed to give the corresponding adducts in moderate to good yields. The scope and limitations as well as the plausible mechanism have been discussed on the basis of control experiments.     

Synthesis and transformations of 1,1,1-trifluoro-2-benzylthiopropene

Conclusions 1,1,1-Trifluoro-2-benzylthiopropene was synthesized and the reactions of this sulfide with electrophiles and nucleophiles (H₂SO₂, SO₂C₁₂ and NHEt₂) leading 1,1,1-trifluoroacetone, 1,1,1-trifluoro-2,3-dichloro-2-benzylthiopropane and 1-trifluoromethy1-2-(N,N-diethylamino)-ethyl benzyl sulfide, respectively, were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 209–211, January, 1987.     

Synthesis and structure of trifluoromethylated arylhydrazones formed from coupling of 4-(dimethylamino)-1,1,1-trifluorobut-3-en-2-one with diazonium salts

A series of trifluoromethyl-containing arylhydrazones were prepared via a direct azo-coupling of (E)-4-(dimethylamino)-1,1,1-trifluorobut-3-en-2-one (1) with different aromatic diazonium salts. Furthermore, we also discussed the non-covalent interactions existing in the crystal structure of compound (E)-4,4,4-trifluoro-2-(2-(4-iodophenyl)hydrazono)-3-oxobutanal (3c) by the X-ray diffraction analysis.     

Facile conversion of 4,4,4-trifluorobut-2-yn-1-ols to 4,4,4-trifluorobut-2-en-1-ones

Smooth isomerization of 4,4,4-trifluorinated propargylic alcohols 1 opened a new and convenient route to readily get access to the corresponding α,β-unsaturated ketones 4 just by heating a THF solution in the presence of Et₃N.     

Synthesis of 1,1,1 - trifluoro-2-penten-4-one

The 1,1,1-trifluoro-2-penten-4-one has been prepared from trifluoroacetaldehyde by two different ways. Its condensation with a cyclohexanone enamine leads, by annelation, to 4-trifluoromethyl-Δ-1,9 (and Δ-9,10)-octalin- 2-one.     

Study on the 1,3-dipolar cycloaddition reaction of 4-ethoxy-1,1,1-trifluoro-3-buten-2-one with nitrile oxides

1,3-Dipolar cycloaddition (1,3-DC) reaction of 4-ethoxy-1,1,1-trifluoro-3-buten-2-one 1 with nitrile oxides was studied. It was found that besides its CC participating in the formation of isoxazole rings, trifluoromethyl activated CO also underwent 1,3-DC reaction with nitrile oxides to afford 1,4,2-dioxazole rings. Single crystal diffraction analysis also evidenced the diheterocyclic configuration.     

Synthesis of 2-pyridones, pyrimidines, and pyrazoles from 1,1,1-trifluoro-4,4-bis(methylthio)but-3-en-2-one

Reactions of 1,1,1-trifluoro-4,4-bis(methylthio)but-3-en-2-one with cyanoacetamide, malonamide, acetoacetamide, amidines, hydrazines, and hydroxylamine gave a number of novel trifluoromethylated heterocyclic compounds containing the methylthio group.     

Synthesis of trifluoromethylated [1,4]diazepines from 1,1,1-trifluoroalk-3-yn-2-ones

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Synthesis of trifluoromethyl-substituted salicylates by cyclocondensation of 1,3-bis(silyloxy)-1,3-butadienes with 4,4-dimethylthio-1,1,1-trifluorobut-3-en-2-one

A formal [3+3] cyclocondensation of 1,3-bis(silyl enol ethers) with the little-known 4,4-dimethylthio-1,1,1-trifluorobut-3-en-2-one was studied. In contrast to 4,4-dimethoxy-1,1,1-trifluorobut-3-en-2-one, this α-oxoketene dithioacetal reacts with 1,3-bis(trimethylsilyloxy)-1,3-butadienes in the presence of TiCl₄ to give mainly 6-methylthio-4-(trifluoromethyl)salicylates via 1,2-addition. The scope and limitations of the reaction are discussed.     

Synthesis and reactions of 3-aminothiazolidine-2-thion-4-one derivatives. 1. Conversion of 3-aminothiazolidine-2-thion-4-one derivatives to substituted mercapto-1,3,4-thiadiazoles

The corresponding carboxymethylthiothiadiazoles are formed by the action of formic acid on 3-aminorhodanine and 3-(3-phenylthioureido)rhodanine, and the action of rhodanineaniline on 3-(3-phenylthioureido)rhodanine leads to 2-anilino-5-carboxy-methylthiothiadiazole anilide, whereas similar treatment of 3-ureidorhodanine leads to a semicarbazide derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 51–53, January, 1981.     

Heterocyclic polyfluoro-compounds. Part XXIV. Synthesis and some reactions of 3-chloro-2,5,6-trifluoro- and 3,5-dichloro-2,6-difluoro-4-iodopyridine

3-Chlorotrifluoro- and 3,5-dichlorodifluoro-4-iodopyridine, easily procured by treatment of 3-chlorotetrafluoro- and 3,5-dichlorotrifluoro-pyridine, respectively, with sodium iodide, yield the corresponding 4,4′-bipyridyls when heated with copper and their 4-$\text{H}$ analogues when reduced with sodium iodide in DMF. 3,5-Dichlorodifluoroisonicotinic acid can be prepared $\text{via}$ lithium-iodine exchange between 3,5-dichlorodifluoro-4-iodopyridine and butyl-lithium.     

Addition reactions of 2-polyfluoroalkyl substituted 1,3-thiazolin-4-one derivatives

2-Polyfluoroalkyl-5-methoxycarbonylmethylene-thiazolin-4-ones react as dienophiles on the exo-cyclic ylidene bond to give spiro-derivatives and as 1,3-dienes with olefins to give dihydropyranothiazole derivatives. The endo-cyclic CN bond in these compounds do not enter into the cycloaddition reactions.