Reactions of alkylenebisbromomalonates with nucleophiles

Treatment of alkylenebisbromomalonates with nucleophiles (AcOK, AgOH, KHCO₃, 1,8-diazabicyclo[5.4.0]undec-7-ene, or Ph₃P) results mainly in their debromination to give cycloalkane-1,1,2,2-tetracarboxylates. When H₂O and acids are present, the reaction gives products of the substitution of one or two bromine atoms by hydrogen. Alkaline hydrolysis results in oxacycloalkane-α,α,α′,α′-tetracarboxylic acids. The reaction mechanism is discussed.     

Reactions of nucleophiles with triarylpropenones and triarylbutenones

From a study of the reactions of nucleophiles with 1,2,3-triaryl-propenones and-butenones in a chemical ionization source it has been found that stronger nucleophiles, such as, MeO^?, EtO^? and MeS^?, attack the α,β-unsaturated system at the β-carbon (Michael addition) or the carbonyl carbon giving rise to tetrahedral adducts, while weaker nucleophiles, such as, Cl^? form the adduct ion by H-bonding with the β-hydrogen. The effect of substituents and source temperature supports the operation of these processes. The triaryl butenone did not give the adduct ion with MeO^? as deprotonation leads to a stable [M ? H]^? ion.     

Reactions of vinylidenediphosphonic acid with nucleophiles

It has been shown that heterocyclic amines can be added to the activated double bond of vinylidenediphosphonic acid to form adducts with betaine structures. Of aliphatic amines only trimethylamine reacts with vinylidenediphosphonic acid.For Part 4, seeIzv. Akad. Nauk, Ser. Khim., 1992, 2180 [Bull. russ. Acad. Sci., Div. Chem. Sci., 1992,41, 1709 (Engl. Transl.)].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1590–1592, August, 1995.     

Reactions of silylium ions with nucleophiles

Transformation of the diethylsilylium cation Et₂Si⁺H into ethyl-and dimethylsilylium ions EtSi⁺H₂ and Me₂Si⁺H in reactions with nucleophiles is induced by electron-donor compounds. Their activity increases in the order Bu₂O < BuOH < (Me₃Si)₂O < C₆H₆ and is determined by the structure of the intermediate adduct and electron density distribution in it. Qualitative estimation shows that the affinity of the tritiated diethylsilylium cation Et₂Si⁺T for a nucleophile increases in the order C₆H₆ < BuOH < Bu₂O < (Me₃Si)₂O. The higher affinity of the Et₂Si⁺H cation for hexamethyldisiloxane compared to dibutyl ether, at similar basicity of the nucleophiles, is attributable to the higher charge of the oxygen atom in (Me₂Si)₂O.     

Reactions of 1,2,4-trichlorotrifluorobenzene with nucleophiles

1,2,4-Trichlorotrifluorobenzene reacted with potassium hydrogen sulfide, potassium hydroxide, sodium isopropoxide, liquid ammonia, and ethyl cyanoacetate via nucleophilic substitution of one fluorine atom with predominant formation of the isomer in which the new substituent replaced fluorine atom in the 5-position.     

Reactions of pyridinium and isoquinolinium phenacylides with nucleophiles

The hydrolysis, alcoholysis, and hydrazinolysis of N-phenacylpyridinium bromide lead to the corresponding benzoic acid derivatives. In addition, 3,6-diphenylpyridazine is formed during hydrazinolysis. The hydrolysis and alcoholysis of N-phenacylisoquinolinium bromide lead to its dimerization, whereas hydrazinolysis gives a triazinoisoquinoline derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 372–374, March, 1976.     

Reactions of nucleophiles with cyclopentadienyliron complexed halotoluenes

η⁶-o-Chlorotoluene-η⁵-cyclopentadienyliron hexafluorophosphate undergoes nucleophilic substitution of the chlorine atom with anions generated (K₂CO₃/DMF) from methyl thioglycolate, diethyl malonate, dimethyl malonate, methyl acetoacetate and 2,4-pentanedione. The compounds prepared were o-CH₃C₆H₄SCH₂CO₂CH₃FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(CO₂C₂H₅)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(CO₂CH₃)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(COCH₃)CO₂CH₃FeCp⁺PF₆⁻ and o-CH₃C₆H₄CH₂COCH₃FeCp⁺PF₆ . Similarly, the reaction of diethyl malonate, dimethyl malonate, methyl acetoacetate anions and methylamine with η⁶-2,6-dichlorotoluene-η⁵-cyclopentadienyliron hexafluorophosphate yielded monosubstitution of one of the chloro groups. The complexes prepared in this study were η⁶-diethyl(3-chloro-2-methyl) phenylmalonate- η⁵-cyclopentadienyliron hexafluorophosphate, η⁶-dimethyl(3-chloro-2-methyl)phenylmalonate-η⁵-cyclopentadienyliron hexafluorophosphate, η⁶-methyl(3-chloro-2-methyl)phenylacetoacetate-η⁵-cyclopentadienyliron hexafluorophosphate and η⁶-3-chloro(2-methyl-N-methyl)aniline-η⁵-cyclopentadienyliron hexafluorophosphate. Reaction of η⁶-2,6-dichlorotoluene-η⁵-cyclopentadienyliron hexafluorophosphate with excess methanol as well as methyl thioglycolate in the presence of K₂CO₃ resulted in disubstitution of both chloro groups to yield new complexes, η⁶-2,6-dimethoxytoluene-η⁵-cyclopentadienyliron hexafluorophosphate and η⁶-methyl[(2-methylphenyl)1,3-dithio] diacetate-η⁵5-cyclopentadienyliron hexafluorophosphate, respectively. Complexes o-CH₃C₆H₄CH(CO₂C₂H₅)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(CO₂CH₃)₂FeCp⁺PF₆⁻ and o-CH₃C₆H₄CH₂ COCH₃FeCp⁺ PF₆⁻ react with excess K₂CO₃ and benzyl bromide in refluxing methylene chloride to give 80–90% yields of complexes o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂CH₃)₂FeCp⁺PF₆⁻ and o-CH₃C₆H₄CH(CH₂C₆H₅)COCH₃FeCp⁺PF₆⁻, respectively. Reaction of complex, o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻ with one molar equivalent of t-BuOK followed by acidic work-up gives o-(C₂H₅CO₂CH₂)C₆H₄CH(CO₂C₂H₅)CH₂C₆H₅FeCp⁺PF₆⁻. Similarly, reactions of complexes o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻ and o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂CH₃)₂FeCp⁺PF₆⁻ with t-BuOK in THF followed by alkylation with methyl iodide gave the new complexes, o-(C₂H₅O₂C(CH₃)CH)C₆H₄CH(CH₂C₆H₅)CO₂C₂H₅FeCp⁺PF₆⁻ and o-(CH₃O₂C(CH₃)CH)C₆H₄CH(CH₂C₆H₅)CO₂CH₃FeCp⁺PF₆⁻, respectively. Vacuum sublimation of the new complexes, o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻ and o-(C₂H₅O₂CCH₂)C₆H₄CH(CH₂C₆H₅)CO₂C₂H₅FeCp⁺PF₆⁻ gives o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂ and O-(C₂H₅O₂CCH₂)C₆H₄CH(CH₂C₆H₅)CO₂C₂H₅, respectively.     

Reactions of β-ethoxyvinylpyrylium salts with nucleophiles

Nitriles, Grignard reagents, and CH-acid compounds attack the -carbon atom in -ethoxyvinylpyrylium salts to give, respectively, nitrilium salts, styrylpyrylium salts, and pyrylomerocyanines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 897–900, July, 1974.     

Reactions of 10-telluroniaanthracene perchlorates with nucleophiles

10-Telluroniaanthracene perchlorates react with nucleophiles (X^–=halide, hydroxide, methoxide) via intermediate free telluroxanthyl radicals. With 9-aryl-10-telluroniaanthracene perchlorates, high yields of 9-aryl-9-X-telluroxanthenes are obtained, but with 10-telluroniaanthracene the principal product is 9,9-bis(telluroxathenyl) as a result of rapid competitive dimerization.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–695, May, 1989.     

Reactions of camphene oxide with sulfur-containing nucleophiles

Sulfur-containing derivatives of the camphene series have been obtained by the nucleophilic addition of isothiouronium salts and thiourea under the conditions of base catalysis.S. V. Kurashov Kazan' State Medical Institute, 420012 Kazan', ul. Butlerova, 12. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 244–246, March–April, 1994.     

Reactions of tetrachloropyridazine with aliphatic nitrogen nucleophiles

Nucleophilic aromatic substitution reactions of tetrachloropyridazine with a series of aliphatic primary and secondary amines led selectively to products arising from replacement of chlorine at the 4‐position in all cases. The structures of the products were unambiguously confirmed by X‐ray crystallography. Substitution occurs at the most activated site para to ring nitrogen, despite the possible steric hindrance to substitution by adjacent chlorine atoms, reflecting the activating influence of ring nitrogen meta to the site of attack. N,N′‐Dimethylethylene diamine gave a mixture of [6,6] ring fused products following initial substitution at the 4‐position.     

Reactions of camphene oxide with sulfur-containing nucleophiles

Sulfur-containing derivatives of the camphene series have been obtained by the nucleophilic addition of isothiouronium salts and thiourea under the conditions of base catalysis. S. V. Kurashov Kazan' State Medical Institute, 420012 Kazan', ul. Butlerova, 12. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 244–246, March–April, 1994.     

Reactions of 4-chlorothiopyrylium cation with nucleophiles

Reactions of 4-chlorothiopyrylium cation (1) with a variety of nucleophiles have been investigated. Thiophenol, aniline, N-methylaniline, sodium phenoxide and sodium methoxide reacted with 1 to give 4-substituted products. On the other hand, Grignard reagents and alkyl amines afforded ring-opened products by nucleophilic attack at the 2-position. The difference in reaction position according to the kind of nucleophile can be reasonably intrepreted in terms of the principle of hard and soft acids and bases. The “aromatic character” of thiopyrylium cation is discussed on the basis of the relative reactivities in nucleophilic substitution of 1, N-methyl-4-chloropyridinium (2) and 4-chloropyrylium (8) cations.     

Trichloropyruvate N-acylimines. Reactions with phosphorus nucleophiles

Reactions of N-aroyltrichloroethaneimines CCl₃C(R)=NCOAr (II, R = COOMe, CN) with phosphorus nucleophiles were studied. The reaction of imines II with o-phenylenediethylamidophosphite proceeded as [4+1]-cycloaddition leading to formation of stable spirocyclic phosphoranes. The structure of one of them was proved by the XRD analysis. The reaction of imine II with acyclic P(III) derivatives [Ph₃P, Ph₂POEt, (PhO)₃P] also includes the formation of labile monocyclic phosphoranes which eliminate phosphine oxide and undergo chlorotropic transfer leading to trichloroazadienes CCl₂=C(R)N=C(Cl)Ar. The reaction of imines II with (EtO)₂POH in the presence of triethylamine leads to the formation of (EtO)₂P(O)Cl and the corresponding dichlorovinylamides CCl₂=C(R)NHCOAr.     

Reactions of alicyclic epoxy compounds with oxygen-centered nucleophiles

The review analyzes the reactions of alicyclic epoxy compounds with oxygen-containing nucleophiles (alcohols, water, and organic acids), describes biologically active products of these reactions, and discusses their mechanisms and results of their simulation by quantum-chemical methods. The regio-and stereoselectivity of nucleophilic reactions of epoxy compounds and the activation of epoxy ring by achiral and chiral catalysts are also considered.     

Reactions of cycloalkeno -1,2,3-selenadiazole with nucleophiles

Reactions of cycloalkeno-1,2,3-selenadiazole and various nucleophiles were studied. In the case of 5-membered ring fused 1,2,3-selenadiazole, nucleophilic attack on selenium atom exclusively resulted in a formation of vinyl selenide derivatives.     

Reactions of halonitroimidazoles with nucleophiles (review)

Published data on the reactions of 4(5)-halo-5(4)-nitro- and 2-halo-4(5)-nitroimidazoles with nucleophiles are reviewed and classified.