Yu. K. Yur'ev

Chemistry of selenophene

The synthesis of a number of β-diketones and 3, 5-disubstituted pyrazoles with 3-selenienyl radicals has been described.

Synthesis of heterocyclic analogs of chalcone containing the selenophene ring

Crotonaldehyde-type condensation using alkaline or acid catalyst is used to synthesize 14 chalcone analogs containing in addition to the selenophene ring, a number of other heterocyclic groups. A Michael adduct is shown to be formed by reaction of 2-acetylselenophene with 2-pyridine aldehyde.

Studies in the furan series. XXXIX. Reaction of furan and 2-methylfuran with acrylonitrile

Furan undergoes a diene-synthesis type of reaction with acrylonitrile to give stereoisomeric 3, 6-endoxotetrahydrobenzonitriles whose configurations are established by PMR spectra. 2-Methylfuran undergoes a similar reaction with acrylonitrile. Some aspects of the relationship between the diene substitution reaction and substitutive addition in the furan series are considered.

The chemistry of selenophene

In the present work it has been shown that 3-(2-selenenoylacetyl)-selenophene is enolized at the carboxyl group adjacent to the 2-selenienyl radical and 3-(benzoylacetyl)selenophene at the carboxyl group adjacent to the phenyl radical (judging from the formation of the corresponding isoxazoles by the reaction of these diketones with hydroxylamine). On reduction with lithium aluminum hydride, methyl 3-selenophenecarboxylate has given 3-selenienylmethanol and the nitrile of the same acid has yielded 3-selenophenealdehyde. Several new chalcones and isoxazoles with β-selenienyl radicals have been described.

Researches on furans: XLI. Synthesis of furan series mercaptans and new type sulfides

The paper investigates the reactions of 3,4-bis (chloromethyl) furan with metal alkyl mercaptides, thiocyanates and sulfides, which are new convenient methods for synthesizing furan series 3,4-disulfides, dithiocyanates, and dimercaptans, and a number of hitherto unknown compounds in the series, thienofurans, and 10-membered heterocyclie ring compounds, dithiecines, with two furan rings.

Electronic absorption spectra of selenophene analogs of chalcones

The electronic absorption spectra of 21 1-(selenienyl-2)-3-arylpropen-1-ones and -3-ones are measured in hexane and ethanol solution. It is found that the 2-selenienyl group in such compounds is more bathochromic and electron-donating than 2-furyl and 2-thienyl. The effects of electron-donating and-accepting substituents onλmax of a longwave band are considered. It is shown that Hammettsσ can be connected with shift in absorption frequency when electron-donating substituents are introduced into the aromatic ring of 1-(selenienyl-2)-3-phenylpropen-1-one. The synthesis of three new selenophene analogs of chalcones is described.

Researches on furans: XL. Reaction of 3, 4 -B is (chloromethyl) furan with primary amines

Study of the reaction of 3,4-bis (chloromethyl) furan with primary aliphatic amines showed that under the conditions chosen, the products are 3,4-bis (alkylaminomethyl) furans which have hitherto not been described in the literature, N-alkyl-4H, 6H-furo [3, 4-c] pyrroles, which are types of compounds hitherto not known in the series, and diazecines which are 10-membered ring compounds with a furan ring.

Comparative basicities of heterocyclic analogs of chalcone

Measurements are made of valence vibration frequency shifts of the hydroxyl group of phenol in carbon tetrachloride solution due to the effect of hydrogen bonding with the carbonyl group (ΔuOH) of chalcone, and its furan, thiophene, selenophene, and N-methylpyrrole analogs. All the compounds form rather stable hydrogen bonds with phenol; ΔuOH varies in the range 200–284 cm−1. For propen-3-ones, where the carbonyl group is remote from the heterocyclic ring, a linear relationship is observed between ΔuOH and pKα, previously determined in 100% sulfuric acid solution in glacial acetic acid. The absence of a linear relationship between these quantities for the other ketones is ascribed to steric factors. It is established that heterocyclic groups exhibit a positive conjugation effect as compared with phenol, decreasing in the order N -methyl-2-pyrryl > 2-furyl > 2-selenienyl > 2-thienyl.

Selenophene chemistry: LVII. Selenophene series ?-diketones with a nitro group in the selenophene ring

Acylation of the copper complexes of benzoyl-, thenoyl-2-, selenoyl-2-acetone with 5-nitroselenophene2-carbonyl chloride followed by hydrolysis of the resultant triketones is a method of synthesizing β-diketones containing the 5-nitroselenienyl group.ω -Benzoyl-,ω -thenoyl-2-, and w-selenoyl-2-(5-nitro-2-acetoselenophene), are prepared in that way, their IR and UV spectra are determined, and the dissociation constants measured. Cu2+ complexes are also prepared.

Basicity and structure of ?,?-unsaturated ketones of the heterocyclic series: IV. Selenophene analogs of chalcone

The protolytic equilibrium constants of 1-(2′-selenienyl)-3-phenyl-1-propenone, 1-(2′-selenienyl)-3-phenyl-3-propenone, and 1, 3-di (2′-selenienyl) propenone have been measured spectrophotometrically in solutions of sulfuric acid (monohydrate) in glacial acetic acid. The results obtained are compared with data on the basicity of chalcone and its thiophene and furan analogs. It is established that, in heterocyclic analogs of chalcone, five-membered heterocycles containing oxygen, sulfur, and selenium show an electron-donating effect which decreases in the order 2-furyl > 2-selenienyl > 2-thienyl.