N. N. Meleshonkova

Formation of acetylenic compounds and ring transformations of 3-alkyl-3-ferrocenylcyclopropenes in the reaction with 1,3-diphenylisobenzofuran

The reaction of 3-ferrocenyl-3-methylcyclopropene with 1,3-diphenylisobenzofuran leads to the formation of exo - and endo -1,4-epoxy-2-ethynyl-2-ferrocenyl-1,4-diphenyltetralines as the main products in addition to the isomeric Diels–Alder exo -adducts. At the same time, 3- tert -butyl- and 3-(1-adamantyl)-3-ferrocenylcyclopropenes form the endo - and exo -adducts of 3-alkyl-1,2-(1-propene-1,3-diyl)ferrocene. The structures of the acetylenic compounds and of the adduct containing a t Bu-substituent are established by X-ray structural analysis. A possible reaction pathway via intermediate zwitter-ion is discussed.

The behaviour of 2-methylene-3-ferrocenylmethylenecamphane under conditions leading to the cyclodimerization of ferrocenyl-1,3-butadienes

The behaviour of 2-methylene-3-ferrocenylmethylenecamphane under proton cyclodimerization conditions has been investigated. The stage involving the formation of the dimeric linear allylic cation has been confirmed in these interactions by isolating of corresponding diene. Its structure has been established unambiguously by X-ray methods. All substances isolated have been characterized by elemental analyses and 1H and 13C NMR spectral data.

Fragmentation reactions of 1,3,5-triferrocenyl-4-(1-ferrocenylvinyl)-, 1-aryl-4-(1-arylvinyl)-3,5-diferrocenyl-, and 3,5-diaryl-1-ferrocenyl-4-(1-ferrocenylvinyl) cyclohexenes

Abstract Monocyclic ferrocenylsubstituted terpenoids, produced upon proton-induced cyclodimerization of ferrocenyl-1,3-dienes, undergo fragmentation under the action of electrophilic agents (HBF 4 , [PhCHFc]BF 4 , or [MeOC 6 H 4 CHCHCHC 6 H 4 OMe]BF 4 ) to give two molecules of methyl-, (2-ferrocenyl-2-phenylethyl)-, or 2,4-bis(p-methoxyphenyl)-3-butenyl-ferrocenylallylium tetrafluoroborates. Treatment of these salts with dimethylaniline yields, depending on their structure, the starting cyclodimers, seven-membered cyclic compounds, dimethylaniline alkylation products, or tricyclic compounds.

Asymmetric Induction in the Synthesis of 3,4,5-Trisubstituted Ferrocenyl-4,5-dihydropyrazoles

The asymmetric induction in the synthesis of 3,4,5-trisubstituted 4,5-dihydropyrazoles with ferrocenyl substituents, starting from the E and Z isomers of α,β-unsaturated ketones was studied. A high diastereoselectivity was revealed at the 1,2 chiral center → chiral center induction, which is independent of the configuration of the starting chalcones.

Behavior ofZ- andE-s-cis-ferrocenyl-1,3-dienes in cycloaddition and dimerization reactions

Z-3-Ferrocenylmethylene-2-methylenecamphane andE-2-ferrocenylmethylene-3-methylenequinuclidine were synthesized by isomerization of the corresponding isomericE- andZ-1,3-dienes in an acidic medium. The dienes obtained form [4+2]-cycloadditionendo-adducts withN-phenylmaleimide, do not form cyclodimers upon thermal or acid-catalyzed [4+2]-cyclodimerization, and addZ-3-ferrocenylmethylene-1,2,7,7-tetramethylbicyclo[2.2.1]hept-2-ylium andE-2-ferrocenylmethylene-3-methyl-1-azoniabicyclo[2.2.1]oct-3-ylium salts, respectively, at the terminal methylene group to give linear addition products. The latter undergo fragmentation on treatment with HBF4 to form the corresponding carbocation tetrafluroborates.

Novel ferrocene-based inhibitor of proteins glycation

Antioxidant and antiglycating activities of 2,6-di-tert-butyl-4-[N-(4-pyridyl)iminomethyl]phenol (1), 2,6-di-tert-butyl-4-[N-(3-pyridylmethyl)-iminomethyl]phenol (2) and N-(3,5-di-tert-butyl-4-hydroxyphenyl)iminomethylferrocene (3) have been studied. Antioxidant activity of 2,6-di-tert-butylphenol bearing ferrocenyl moiety was shown to be sufficiently higher than that of the compounds 1 and 2. Based on the data obtained in comparison with aminoguanidine which is an effective protein glycation inhibitor it was established that the introduction of ferrocenyl moiety into 2,6-di-tert-butylphenol results in a dramatic increase in the antiglycating activity exceeding that for aminoguanidine.

3-Cyclobutyl-3-ferrocenylcyclopropene and 3-cyclobutylidene-3-ferrocenylpropyne. Synthesis and chemical properties

Abstract3-Cyclobutyl-3-ferrocenylcyclopropene was synthesized by the reactions of mono- or dibromoferrocenylcyclopropanes with ButOK in DMSO. Treatment of dibromoferro-cenylcyclopropane with ButOK in THF afforded 3-cyclobutylidene-3-ferrocenylpropyne in 52% yield. Heterolysis of the C-C bond in the three-membered ring of 3-cyclobutyl-3-ferrocenylcyclopropene at low and high temperatures was studied. Hydrolysis yielded 3-cyclobutyl-1H-cyclopentaferrocene and products with linear structures,viz., 3-cyclobutylidene-3-ferrocenylpropene,E- andZ-I-ferrocenyl-1-cyclobutylpropenes, and 1-cyclobutylidene-1-ferrocenylacetone. Cyclopropene reacts with 1,3-diphenylisobenzofuran to form two Diels-Alder adducts, while the enyne does not react with 1,3-diphenylbenzofuran.

Addition of tris(trimethylsilyl) phosphite to quinuclidin-3-one and its carbocyclic analogs

Convenient methods of synthesis of functionalized phosphonic acids and their trimethylsilyl esters containing quinuclidine, adamantine, and bornane (camphane) moieties, involving reactions of tris(trimethylsilyl) phosphite with quinuclidin-3-one and its carbocyclic analogs.

3,5-Bis(ferrocenylmethylene)-1-methyl-4-methylenepiperidine. Synthesis and some chemical properties

Abstract3,5-Bis(ferrocenylmethylene)-1-methyl-4-methylenepiperidine, a diferrocenyltriene with a fixeds-cisoid conformation of the exocyclic double bonds, was synthesized. On heating, this compound cyclodimerizes according to the [4+2]-cycloaddition scheme; it forms Diels-Alder adducts with azodicarboxylic and maleic acidN-phenylimides. The compound easily cyclodimerizes in the presence of acids by a proton cyclodimerization mechanism to give a spiro cyclodimer. The triene also adds a 3,5-bis(ferrocenylmethylene)-1,4-dimethyl-1-azonia-4-cyclohexyl salt to the terminal methylene group yielding linear and cyclic addition products.