Synthesis and structures of the CH acid salts obtained in the reactions of malonic acid esters and malononitriles with 2,4,6-trinitrohalobenzenes in the presence of triethylamine

Reactions of dimethyl malonate, diphenyl malonate, methyl cyanoacetate, and malononitrile with 1-chloro-2,4,6-trinitrobenzene or 1-fluoro-2,4,6-trinitrobenzene in the presence of triethylamine in organic solvents gave stable brightly colored crystalline triethylammonium salts of the corresponding 2,4,6-trinitrophenylmalonic acid derivatives.     

Condensation products of mono-and dibromo-substituted methyl vinyl sulfones with CH-acids enolates

Bromomethyl (E)-2-phenylethenyl and bromomethyl (Z)-1-bromo-2-phenylethenyl sulfones undergo condensation with enolates generated from malononitrile, dimethyl malonate, methyl and ethyl acetoacetate using NaH in THF to give tetrahydrothiophene S,S-dioxides. Methyl (E)-1-bromo-2-phenylethenyl and methyl (E)-2-bromo-2-phenylethenyl sulfones react with sodium malononitrile to give 2-[2-(methylsulfonyl)-1-phenylethylidene]malononitrile. The bromomethyl-(E)-2-bromo-2-phenyl ethenyl sulfone reacts with sodium malononitrile to give 2-[2-(bromomethylsulfonyl)-1-phenylethylidene]malononitrile exclusively. Dedicated to Professor A. A. Potekhin’s memory. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 539–551, April, 2008.     

Reaction of 1-bromovinyl and 1-bromo-2-phenylvinyl sulfones with some CH acids

Benzyl, methyl, and phenyl α-bromovinyl sulfones reacted with malononitrile and dimethyl malonate sodium enolates in THF to give sulfonyl-substituted cyclopropanes. Reactions of the same sulfones with methyl acetoacetate sodium enolate afforded the corresponding sulfonyl-substituted cyclopropanes as mixtures of cis and trans isomers with a small impurity of 5-sulfonyl-4,5-dihydrofuran derivative. Phenyl and p-tolyl 1-bromo-2-phenylvinyl sulfones reacted with methyl acetoacetate sodium salt to produce a mixture of trans-isomeric 5-sulfonyl-4,5-dihydrofuran and Michael adduct of the CH acid with activated acetylene generated by concurrent 1,2-dehydrobromination of the initial α-bromovinyl sulfone.     

Tandem transformations of bromo-substituted β-(methylsulfonyl)styrenes in reactions with dimethyl malonate,methyl cyanoacetate,and methyl acetoacetate

β-Bromo-β-(methylsulfonyl)styrene reacted with dimethyl malonate and methyl cyanoacetate in the presence of sodium hydride to give sulfonyl-substituted cyclopropanes, and sulfonyl-substituted 2,3-dihydrofuran was also formed in the reaction with methyl acetoacetate. Reactions of α-bromo-β-(bromomethylsulfonyl) styrene with dimethyl malonate and methyl cyanoacetate led to the formation of 2,3-dihydro-λ⁶-thiophene S,S-dioxide derivatives. In the reaction of α-bromo-β-(bromomethylsulfonyl)styrene with methyl acetoacetate, 2,3-dihydro-λ⁶-thiophene S,S-dioxide and 2,5-dihydro-λ⁶-thiophene S,S-dioxide derivatives and methyl acetoacetate O-alkylation product, methyl 3-[(E)-2-(bromomethylsulfonyl)-1-phenylvinyloxy]but-2-enoate, were obtained at a ratio of 2.7: 1.2: 1. α-Bromo-β-(methylsulfonyl)styrene reacted with dimethyl malonate to produce dimethyl 2-[2-(methylsulfonyl)-1-phenylethylidene]malonate. The reaction of β-bromo-β-(bromomethylsulfonyl) styrene with dimethyl malonate and methyl cyanoacetate were strictly stereoselective, and they afforded tetrahydro-λ⁶-thiophene S,S-dioxide derivatives. The reaction of the same substituted styrene with methyl acetoacetate was not stereoselective, and the products were two diastereoisomeric tetrahydro-λ⁶-thiophene S,S-dioxides and sulfonyl-substituted 2,3-dihydrofuran at a ratio of 2.3: 2.7: 1.     

Complexing and catalytic properties of easily available chiral iminophosphite based on biphenyl-2,2"-diol

A chiral iminophosphite ligand based on biphenyl-2,2"-diol and its chelates with rhodium(i) and palladium(ii) were synthesized for the first time. Successful use of these compounds in asymmetric allylic substitution was demonstrated. The enantioselectivity of palladium-catalyzed alkylation of methyl pent-3-en-2-yl carbonate with dimethyl malonate reached 70%, that in the alkylation of 1,3-diphenylallyl acetate with dimethyl malonate was 88%. In the rhodium-catalyzed sulfonylation of 1,3-diphenylallyl acetate with sodium p-toluenesulfinite, the enantioselectivity was 56%.     

Oxidative Addition of Dimethyl Malonate to Styrenes Mediated by Cerium(Iv) Ammonium Nitrate: Some Novel Observations

The oxidative addition of dimethyl malonate to ring substituted styrenes leads to the formation of substituted dimethyl (2-oxo-2-phenylethyl) malonate and methyl 2-oxo-5-phenyltetrahydrofuran-3-carboxylate along with small amounts of substituted dimethyl [2-(nitrooxy)-2-phenylethyl] malonate and dimethyl 2-methoxy-2-phenylethyl) malonate. A tentative mechanism which supports the formation of these products is also presented.     

Synthesis of pyrimidine derivatives using N-bis(methylthio)methylenecyanamide

N-Bis(methylthio)methylenecyanamide ( 1 ) was allowed to react with active methylene compounds (methyl cyanoacetate, dimethyl malonate, ethyl acetoacetate, ethyl phenylacetate) in the presence of potassium carbonate or potassium hydroxide in dimethyl sulfoxide followed by the treatment using appropriate a base or an acid to give the corresponding 6-methylthiouracil derivatives in 15–80% yields. These uracil derivatives are found to be useful intermediates for the synthesis of 6-aminouracils and fused pyrimidine derivatives.     

Reaction of 3-Methyleneisocamphanone with Derivatives of Malonic Acid

Reaction of 3-methyleneisocamphanone with malononitrile, ethyl cyanoacetate or diethyl malonate in the presence of catalytic quantities of alkali or under catalysis with tetramethylguanidine in ethanol proceeds according to classical scheme of the Michael reaction and gives rise to 3-exo-(2,2-dicyanoethyl)-, 3-exo-(2-cyano-2-ethoxycarbonylethyl)-, or 3-exo-(2,2-diethoxycarbonylethyl)isocamphanone respectively. When the reaction with ethyl cyanoacetate and diethyl malonate is carried out in methanol occurs transalkylation of the ester groups resulting in the corresponding methyl esters, and in THF occurs hydrolysis to form carboxylic acids. In ethanol or methanol in the presence of equimolar or excess amounts of alkali compounds with cyano groups suffer cyclization into the corresponding 2-alkoxy-3-cyano- or 1-alkoxy-3-alkoxycarbonyl-7,7,8-trimethylbicyclo[2.2.1]hepteno[2.3-b]pyridines. In THF partially form analogous tricyclic 2-hydroxypyridines.     

1,6-Additionen an 3-Methyl-5-methyliden-2-(5H)-furanon-Derivate

1,6-Additions to 3-Methyl-5-methylidene-2(5H)-furanone Derivatives The anions of thiophenol, methyl malonate and malononitrile react with 3-methyl-5,6-dihydro-2 (4H)-benzofuranone ( 1c ) by the formation of the corresponding 1,6-addition products cis- 5c (63%), trans- 6 (42%) and trans- 7 (76%), respectively. Likewise, the reaction of 3-methyl-5-methylidene-2 (5H)-furanone ( 1b ) with thiophenol yields the 1,6-addition product 5b (66%), and with the sodium salt of methyl aceto-acetate the 1,6-addition product 8 (11%) and the dispiro-dilactone 9 (39%).     

Electrochemical co-oxidation of C-H acids and methanol as a new route to functionalized cyclopropanes

Electrolysis of dimethyl malonate or methyl cyanoacetate in methanol in the presence of LiCl in an undivided cell leads to formation of 1,1,2,2-cyclopropanetetracarboxylic derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1835–1836, October, 1994.This work was supported by the International Science Foundation (Grant No MHY 000).     

Rhodium-catalyzed cyclopropanations of 2-aryl-2H-chromenes with dialkyl malonate esters. A comparison of α-diazo derivatives and phenyliodonium ylides

Rhodium-catalyzed reactions of 2-aryl-substituted 2H-chromenes with α-diazo esters prepared from dimethyl and tert-butyl methyl malonates were investigated, and the results were compared with reactions carried out with phenyliodonium ylides prepared from the same esters. The phenyliodonium ylide prepared from dimethyl malonate was found to give superior yields of cyclopropane products compared to the corresponding α-diazo equivalent. However, this result was reversed with tert-butyl methyl malonate when Rh₂(S-TBSP)₄ was used to decompose the diazo compound. All reactions gave 1,1-cyclopropane diesters as single diastereomers.     

Reactions of Zinc Enolates Formed from 1-Aryl-2-bromo-2-phenylethanone or 2-Bromoindanone and Zinc,with Dimethyl 2-(1-Arylmethylene)malonates

Zinc enolates formed from 1-aryl-2-bromo-2-phenylethanones and zinc react with dimethyl 2-(1-arylmethylene)malonates to afford dimethyl 2-(1,3-diaryl-3-oxo-2-phenylpropyl)malonates. The latter react with cyclohexylamine, piperidine, or morpholine to give the corresponding monosubstituted amides. The zinc enolate derived from 2-bromoindanone and zinc reacts with dimethyl 2-(4-bromobenzylidene)malonate, yielding dimethyl 2-[(4-bromophenyl)(1-oxoindan-2-yl)methyl]malonate. The final products largely form as a single diastereomer.     

Palladium-catalyzed asymmetric intramolecular allylation forming optically active vinylcyclopropane and vinyldihydrofurans

Reaction of 2-butenylene dicarbonate with dimethyl malonate and methyl acetylacetate in the presence of a chiral ferrocenylphosphine-palladium catalyst gave optically active dimethyl 2-vinylcyclopropane-1,1-dicarboxylate (70% ee) and methyl 2-methyl-5-vinyl-4,5-dihydrofuran-3-carboxylate (59% ee), respectively.     

Imidazolium-Based Phosphinite Ionic Liquid (IL-OPPh2) as Reusable Catalyst and Solvent for the Knoevenagel Condensation Reaction

A task-specific ionic liquid (IL, OPPh₂) that bears a phosphinite weak Lewis base group in an imidazolium cation was found to efficiently catalyze the Knoevenagel condensation of arylaldehydes with malononitrile, dimethyl(diethyl)malonate, and ethyl cyanoacetate. This IL plays a dual role as both the reaction media and also catalyst, and it can be easily recovered and reused in several runs. Satisfactory results were obtained with good yields, short reaction time, and simplicity in the experimental procedure. A variety of coumarin derivatives were synthesized in this procedure.     

Réaction d'imidoylation: Réactivité de composés à méthylène actif avec les O-ethylcarbamates cycliques

Condensation of malononitrile, ethyl cyanacetate and isopropylidene malonate with various O-ethyl cyclic carbamates leads to α-(tetrahydrox- azole-1.3-ylidene-2) and α-(tetrahydroxazine-l,3-ylidene-2)malono- nitriles, ethyl cyanacetates and isopropylidene malonates.     

Heterocyclization of dimethyl malonate with SH acids and formaldehyde in the presence of catalysts

Three-component heterocyclization of dimethyl malonate with SH acids (H₂S, ethane-1,2-dithiol) and formaldehyde in the presence of 5 mol % of transition metal chlorides (FeCl₃, CoCl₂, NiCl₂) gave dimethyl 1,3-dithiane-5,5-dicarboxylate and dimethyl 1,4-dithiepane-6,6-dicarboxylate. The reactions in the presence of transition metal chlorides hydrates were accompanied by Krapcho decarboxylation with formation of methyl 1,3-dithiane-5-carboxylate and methyl 1,4-dithiepane-6-carboxylate.     

Reactions of some alken-1-yl and cycloalken-1-yl bromomethyl sulfones with dimethyl malonate and malononitrile

Bromomethyl cyclopent-1-enyl sulfone and bromomethyl cyclohex-1-enyl sulfone reacted with dimethyl malonate and malononitrile sodium salts in THF at 20?C50°C to give products of Michael-induced Ramberg-B?cklund reaction, functionalized derivatives of methylidenecyclopentane and methylidenecyclohexane. Reactions of bromomethyl hex-1-en-1-yl sulfone and bromomethyl hept-1-en-1-yl sulfones with the same sodium enolates followed the Michael-induced ring closure pattern with formation of tetrahydrothiophene 1,1-dioxide derivatives containing allylmalonic acid derivatives as impurities. Factors responsible for the different reaction pathways of cyclic and acyclic bromomethyl sulfones are discussed.     

Differences in the crystal structures of two dialkyl diester triphenyl­phospho­nium ylids

Hydrogen bonding and crystal packing play major roles in determining the conformations of ethyl methyl 2‐(triphenyl­phospho­ranyl­idene)malonate, Ph₃P=C(CO₂CH₃)CO₂CH₂CH₃ or C₂₄H₂₃O₄P, (I), and dimethyl 2‐(triphenyl­phosphor­anyl­idene)malonate, Ph₃P=C(CO₂CH₃)₂ or C₂₃H₂₁O₄P, (II). In (I), the acyl O atom of the ethyl ester group is anti to the P atom, while the O atom of the methyl ester group is syn. In (II), the dimethyl diester is a 1:1 mixture of anti–anti and syn–anti conformers.     

Magnetic nanoparticle-supported eosin Y ammonium salt: An efficient heterogeneous catalyst for visible light oxidative C–C and C–P bond formation

A highly efficient visible light mediated C–C and C–P coupling reactions of sp³ C–H bonds adjacent to the nitrogen atom in tetrahydroisoquinoline derivatives with pronucleophiles such as nitroalkanes, malononitrile, dimethyl malonate and H-phosphonate diesters were achieved by using a magnetic nanoparticle-supported eosin Y bis-benzyltriethylammonium salt (MNPs-Eosin Y) as catalyst and air as the sole oxidant, affording the corresponding products in good to excellent yields under mild reaction conditions. Notably, the supported eosin Y catalyst can easily be separated from the reaction mixture by an external permanent magnet and can be recycled at least eight times without a significant loss of activity.     

Utility of Enaminonitriles in Heterocyclic Synthesis: Synthesis of Some New Pyrazole,Pyridine, and Pyrimidine Derivatives

The starting (1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)carbonohydrazonoyl dicyanide ( 2 ) was used as key intermediate for the synthesis of 3‐amino‐2‐(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐ylazo)‐[3‐substituted]‐1‐yl‐acrylonitrile derivatives ( 3 – 10 ). In addition, nitrile derivative 2 reacted with hydrazine hydrate or malononitrile to afford the corresponding 3,5‐diaminopyrazole 11 and enaminonitrile derivative 13 , respectively. On the other hand, compound 3 was subjected to react with malononitrile, acetic anhydride, triethylorthoformate, N,N‐dimethylformamide (DMF)‐dimethylacetal, thiourea, and hydroxylamine hydrchloride to afford antipyrine derivatives 16 – 21 . Moreover, the reaction of enaminonitrile 3 with carbon disulfide in pyridine afforded the pyrimidine derivative 22 , whereas, in NaOH/DMF followed by the addition of dimethyl sulphate afforded methyl carbonodithioate 24 . The reaction of enaminonitrile derivatives 3 – 5 with phenylisothiocyanate afforded the thiopyrimidine derivatives 25a – c . Finally, the enaminonitrile 4 reacted with 3‐(4‐chloro‐phenyl)‐1‐phenyl‐propenone to afford the pyridine derivative 27 . The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, ¹³C‐NMR, ¹H–NMR, and MS).