- CATHODIC SYNTHESIS OF ESTERS OF 1,1,2,2-CYCLOALKANETETRACARBOXYLIC ACIDS DERIVED FROM 1,1,2,2-ETHANE- OR ETHYLENECARBOXYLATE ESTERS
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The cathodic electrolysis of esters of 1,1,2,2-ethane- or ethylenetetracarboxylic acids in the presence of dihaloalkanes leads to esters of 1,1,2,2-cycloalkanetetracarboxylic acids. Keywords: acyclic compounds, esters, alkyl bromides, electrochemical synthesis, electrolytic reduction.
- Vasil'ev, A. A.,Zvolinskii, V. I.,Petrosyan, V. A.
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- Electrochemical oxidation of malonic esters in acetonitrile in the presence of iodides as mediators
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Electrochemical oxidation of malonic esters in acetonitrile in the presence of iodides follows two different pathways depending on the nature of the cation. In the presence of LiI, alkyl 1,1,2,2,3,3-propanetetracarboxylates were obtained in 85-98% yields. In the presence of NaI, KI, or Bu4NI, the formation of 1,1,2,2-ethanetetracarboxylates and their subsequent dehydrogenation to ethenetetracarboxylates was the main reaction pathway.
- Fedukovich,Elinson,Nikishin
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- Chemical and Electrochemical Oxidative Dimerization of Carbonyl Compounds by Cerium(IV) Salts. A Comparative Study
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β-dicarbonyl and β-cyanocarbonyl compounds were dimerized chemically by CAN or by electrocatalysis using cerous nitrate as mediator.The saturated and unsaturated products of these oxidations are presented.
- Cho, Liu Yao,Romero, Jose Ricardo
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- Simple synthesis of tetra-acceptor-substituted alkenes by the formal dehydrodimerization of malonates
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Only two steps are required for the synthesis of tetra-acceptor- substituted alkenes from simple malonates in excellent yields [Eq. (1)]. The method is characterized by cheap and commercially available precursors, and ultrasound remarkably accelerates the radical reaction as well as the successive Knoevenagel reaction.
- Linker, Torsten,Linker, Ursula
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- All-Carbon Tetrasubstituted Olefins Synthesis from Diazo Compounds and Iodonium Ylides under Blue LED Irradiation
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A route for the construction of all-carbon tetra-substituted olefins through visible-light promoted coupling of diazo compounds with iodonium ylides was developed. A wide range of all-carbon tetra-substituted olefins was obtained in moderate to good yields. The synthetic values of the current method were further approved by the synthesis of natural isolates modified alkenes and the successful transformation of final olefins into important heterocycles. (Figure presented.).
- Li, Lei,Xu, Guo-Yong,Xuan, Jun,Zhao, Yan-Rui
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- Cu-Mediated arylselenylation of aryl halides with trifluoromethyl aryl selenonium ylides
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An unprecedented arylselenylation of aryl halides with trifluoromethyl aryl selenonium ylides in the presence of copper is described. The reaction proceeded at 100-140 °C under ligand- and additive-free conditions for 3-20 h to form a variety of unsymmetrical diaryl selenides in good to high yields. Arylselenylation is easy to operate, has good functional group tolerance, and demonstrates the different reaction profiles of trifluoromethyl aryl selenonium ylides from the homologous trifluoromethyl aryl sulfonium ylides.
- Wu, Shuai,Shi, Jin,Zhang, Cheng-Pan
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p. 7468 - 7473
(2019/08/20)
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- Continuous Processing and Efficient in Situ Reaction Monitoring of a Hypervalent Iodine(III) Mediated Cyclopropanation Using Benchtop NMR Spectroscopy
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Real-time NMR spectroscopy has proven to be a rapid and an effective monitoring tool to study the hypervalent iodine(III) mediated cyclopropanation. With the ever increasing number of new synthetic methods for carbon-carbon bond formation, the NMR in situ monitoring of reactions is becoming a highly desirable enabling method. In this study, we have demonstrated the versatility of benchtop NMR using inline and online real-time monitoring methods to access mutually complementary information for process understanding, and we developed new approaches for real-time monitoring addressing challenges associated with better integration into continuous processes.
- Ahmed-Omer, Batool,Sliwinski, Eric,Cerroti, John P.,Ley, Steven V.
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p. 1603 - 1614
(2016/09/23)
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- A catalytic approach to the base-promoted reaction of epoxides with activated methylenes
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This contribution reports the results obtained in the definition of a catalytic method for the nucleophilic ring opening of epoxides by activated methylenes promoted by a polymer-supported base. The attention has been focused on the use of polymer supported bases and the best results have been obtained by using 4-(dimethylamino)pyridine (PS-DMAP) and 2-tert-butylimino-2-diethylamino-1,3-dimethyl-perhydro-1,3,2-diazaphosphorine both on polystyrene (PS-BEMP). Solvent-free conditions has been essential for reaching a sufficient reactivity to realize this process, in fact when a reaction medium is used, the processes are almost unfeasible.
- Angelini, Tommaso,Fringuelli, Francesco,Lanari, Daniela,Pizzo, Ferdinando,Vaccaro, Luigi
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supporting information; experimental part
p. 1566 - 1569
(2010/06/13)
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- RhII-catalyzed cycloadditions of carbomethoxy iodonium ylides
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Carbomethoxy iodonium ylides, generated from methyl acetoacetate and methyl malonate, respectively, are exploited in synthesis of cyclopropanes, cyclopropenes as well as various heterocycles.
- Batsila, Christina,Kostakis, George,Hadjiarapoglou, Lazaros P
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p. 5997 - 6000
(2007/10/03)
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- Tetramethyl ethene-1,1,2,2-tetracarboxylate: Oxidative homocoupling of dimethyl malonate in the presence of magnesium oxide
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Dimethyl malonate oxidized with CAN in the presence of magnesium oxide forms tetramethyl 1-hydroxyethane-1,1,2,2-tetracarboxylate and tetramethyl ethene-1,1,2,2-tetracarboxylate in high yield. Subsequent dehydration of the mixture provides exclusively tetramethyl ethene-1,1,2,2-tetracarboxylate.
- Skarzewski,Zon
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p. 2953 - 2957
(2007/10/03)
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- The photolytic disproportionation of dialkyl 2,2-di(phenylseleno)propanedioates
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Dialkyl-2,2-di(phenylseleno)propanedioates undergo disproportionation to form tetralkyl 1,1,2,2-ethylene tetracarboxylates and diphenyl diselenide upon photolysis. Evidence for the intermediacy of a capto-dative radical intermediate in this process is described.
- Byers,Thissell
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- Radical Addition Reactions of 2-(Phenylseleno)propanedioates to Alkenes and Alkynes
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Sunlamp photolysis of methyl or ethyl 2-(phenylseleno)propanedioate with a variety of alkenes and alkynes in benzene yielded addition products in good to excellent yields.The proposed mechanism involves a radical chain process in which addition of a malonate ester radical is followed by phenylseleno transfer.Monosubstituted alkenes, 1,1- and 1,2-disubstituted alkenes, terminal alkynes, and internal alkynes were shown to undergo this reaction.Addition to diallyl ether led to substituted tetrahydrofurans, characteristic of process involving initial addition, followed by cyclization prior to phenylseleno transfer.Vinyl arenes, conjugated dienes, and unsaturated carbonyl compounds proved unreactive.
- Byers, Jeffrey H.,Lane, Gregory C.
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p. 3355 - 3360
(2007/10/02)
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- INVESTIGATION OF THE REACTION OF DIMETHYL DIAZOMALONATE WITH 1-PHENYLCYCLODODECENE IN THE PRESENCE OF COPPER(II) ACETYLACETONATE
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Cu(AcAc)2 catalyzed reaction of dimethyl diazomalonate (dmdm) with 1-phenylcyclododecene was realized under different molar ratios and new compounds were obtained. The best procedures for synthesis of the addition products were noticed and the presence of a triploid-type carbenoid was claimed.
- Guenaydin, Keriman,Anac, Olcay
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p. 1325 - 1330
(2007/10/03)
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- Cyclic Selenonium exo-Ylides (3,4-Dihydro-1H-2-benzoselenin-2-io)methanides; Syntheses and Reactions
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Stable cyclic selenonium exo-ylides (3,4-dihydro-1H-2-benzoselenin-2-io)methanides; (5a-e) have been synthesized by reactions of 3,4-dihydro-1H-2-benzoselenin-2,2-dichloride (4) or N-(3,4-dihydro-1H-2-benzoselenin-2-io)toluene-p-sulphonamidate (6) and active methylene compounds.The ylidic nature and the stable configuration of (5a-e) were established on the basis of their spectral data.The reactions of ylides having acetyl group(s) (5a,b) with dimethyl acetylenedicarboxylate afforded the furan derivatives (8a,b) and (9a) and the dihydrobenzoselenin (3), while reactions of the ylides having no acetyl group, (5c-e), afforded the benzoselenonines (14c-e).The diacetylmethanide (5a) when heated gave the benzoselenepine (15), while (5c) when heated afforded the styrene derivative (18) and a tetrasubstituted ethylene (19).When heated, (5d) gave the rearranged product (22). 3,4-Dihydro-1H-2-benzoselenin-2-io)phenacylide (31) was generated by the reaction of the selenonium salt (24) with sodium hydride but was too unstable to be isolated.Thermal decomposition of (31) yielded (3), its counterparts (26-28), a styrene derivative (25), and a novel rearrangement product (29).
- Hori, Mikio,Kataoka, Tadashi,Shimizu, Hiroshi,Tsutsumi, Kazuhiro,Hu, Yong-Zhou,Nishigiri, Motoo
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- ELECTROCHEMICAL CYCLIZATION OF TETRAMETHYL ESTERS OF 2-SUBSTITUTED PROPANE-1,1,3,3-TETRACARBOXYLIC ACIDS IN THE PRESENCE OF SALTS OF HYDROHALIC ACIDS
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The chemical and electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of hydrohylic acid salt mediators were studied.It was found that the chemical variant of the cyclization of the corresponding α,α'-dianions of esters of propane-1,1,3,3-tetracarboxylic acids by the action of iodine or bromine is substantially inferior to the electrochemical variant.In the latter case, the esters of substituted cyclopropane-1,1,3,3-tetracarboxylic acids are formed in a 87-98percent yield.The tetramethyl ester of 2-isopropylpropane-1,1,3,3-tetracarboxylic acid, which under the electrolysis conditions decomposes according to a Michael retroreaction is an exception.
- Elinson, M. N.,Fedukovich, S. K.,Nikishin, G. I.
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p. 2523 - 2529
(2007/10/02)
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- Bis(dimethyl malonato)ketazine. Formation and inversion/rotation barrier
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Decomposition of neat dimethyl diazomalonate (1) with rhodium(II) acetate dimer gave the azine, 3, as the major product. Dynamic NMR spectroscopy provided the activation parameters for the inversion/rotation barrier of 3.
- Pomerantz, Martin,Levanon, Moshe
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p. 4265 - 4266
(2007/10/02)
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- TRIBUTYLSTIBINE MEDIATED SYNTHESIS OF 1,1,2-TRI-SUBSTITUTED CYCLOPROPANES
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A novel method for the synthesis of 1,1,2-tri-substituted cyclopropanes is reported which involves the reaction of electron-deficient olefins with dibromomalonic ester, dibromocyanoacetic or dibromobenzeneacetic ester promoted by tri-n-butylstibine.The reaction was carried out under mild conditions to give the cyclopropane derivatives in moderate to good yields.Other R3M (M= As,Sb,Bi) reagents as promoter for this reaction have been studied and seem to be less effective than tributylstibine.
- Chen, Chen,Liao, Yi,Huang, Yao-Zeng
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p. 3011 - 3020
(2007/10/02)
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- Reactions of α,β-Unsaturated Carboxylates, Malonates and Phenylacetates with Manganese(III) Acetate in the Presence of Chloride Ions
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The reaction of alkyl (E)-3-phenylpropenoates with manganese(III) acetate of Cl- ions gave alkyl (Z)-2-chloro-3-phenylpropenoates and alkyl 2,3-dichloro-3-phenylpropenoates.Ethyl (E)-2,3-diphenylpropenoate yielded ethyl 2,3-dichloro-2,3-diphenylpropanoate.Alkyl 3,3-diphenylpropenoates gave mainly alkyl 2-chloro-3,3-diphenylpropenoates.Ethyl 1-cyclohexenecarboxylate gave ethyl 1,2-dichlorocyclohexanecarboxylate.Dimethyl malonate yielded dimethyl dichloromalonate and tetramethyl 1,2-dichloro-1,1,2,2-ethanetetracarboxylate.Substituted malonates resulted in α-chloro derivatives.Methyl phenylacetates gave α-acetoxy derivatives.
- Yonemura, Hiroshi,Nishino, Hiroshi,Kurosawa, Kazu
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p. 809 - 811
(2007/10/02)
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- Thiophene S,N-Ylides: A New Versatile Class of Sulphimides
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Tetrachlorothiophene reacts with methyl, ethyl, and phenyl azidoformates and with toluene-p-sulphonyl azide at 130-150 deg C to give stable thiophene S,N-ylides. 2,5-Dichloro and 2,5-dibromo-thiophene and tetrabromothiophene yield products derived by nitrene attack at the α-position.The S,N-ylides undergo ready photolysis to liberate the parent nitrene, and react with a wide variety of electron-rich dienophiles as 4?-components to give tetrachlorodihydrobenzenes with extrusion of a thionitroso compound.With dienes the ylides react either as 2?- or 4?-systems.Thus with anthracene a dihydrothiophene analogue of triptycene is generated efficiently aromatised and de-ylidated with zinc in methanol.With dimethyl acetylenedicarboxylate the ylides yield a thiazocine by a novel ring expansion.Oxidation of the ylide system with 3-chloroperbenzoic acid gives the corresponding ylide S-oxide.Tetrachlorothiophene also reacts efficiently with diazoalkanes under rhodium acetate catalysis to give thiophene S,C-ylides, which undergo cycloaddition with nucleophilic alkenes much more slowly than their nitrogen analogues.
- Meth-Cohn, Otto,Vuuren, Gerda van
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p. 233 - 244
(2007/10/02)
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- REACTIONS DE CYCLISATIONS INDUITES PAR DES FLUORURES ALCALINS : FORMATION DE CYCLOPROPANES.
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Fluorides acted as bases in cyclopropane ring formation from nucleophiles and Michael acceptors.With cyano alkenes, Si(OR)4 improved the yields of the reaction.
- Joucla, M.,Brun, J. Le
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p. 3001 - 3004
(2007/10/02)
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- Cycloaddition Reactions of Thiophene S,N-Ylides. A Novel Route to Thionitroso Compounds
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Thiophene S,N-ylides readily react with electron-rich dienophiles yielding adducts formed by the efficient extrusion of acyl- and sulphonyl-thionitroso-compounds, themselves readily trapped by Diels-Alder or ene reactions; similar but slower cycloadditions occur with the analogous S,C-ylides, a potential source of thiocarbonyl derivatives.
- Meth-Cohn, Otto,Vuuren, Gerda van
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p. 1144 - 1146
(2007/10/02)
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- REACTIONS INVOLVING TRANSITION METALS. XVII. REACTION OF ORGANIC HALOGEN COMPOUNDS WITH 2 AND 2 (S = CH2Cl2, THF)
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The complexes 2 and 2 (S=CH2Cl2, THF) have been shown to react with CXCl3 (X=Cl, H) to form with generation of both dichlorocarbene and trichloromethyl radical.Reaction of 2 with CF3I, allyl- and benzyl-halides takes a different course giving organic coupling products and .The THF solvate complex also causes coupling of gem-dihalides, and dehalogenation of vic-dihalides to produce alkenes.Possible mechanisms for these reactions are discussed.
- Booth, Brian L.,Casey, Geoffrey C.,Haszeldine, Robert N.
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p. 197 - 205
(2007/10/02)
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- THE EFFECTS OF DIFFERENT COPPER (AND SOME OTHER) CATALYSTS ON THE CONVERSION OF TRIPHENYL- AND TETRAPHENYL-DIAZOCYCLOPENTADIENES AND OF SOME PHENYLIODONIUM αα'-DICARBONYLYLIDES INTO ARSONIUM AND OTHER YLIDES
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Diazo-compounds or iodonium ylides may be converted into arsonium and other ylides when heated in solution with triphenylarsine or other suitable carbene (or carbenoid) acceptor, and with a suitable Cu derivative present.The effects of using different copper complexes and salts are described and discussed.Other metal derivatives were for the most part ineffetive as catalysts.
- Hood, J. Nicholas C.,Lloyd, Douglas,MacDonald, William A.,Shepherd, T. Maurice
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p. 3355 - 3358
(2007/10/02)
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- The Low-temperature Photolysis of Diazo Compounds. The Utility of Tertiary Alcohol in Matrix Studies of Carbene Chemistry
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Carbene processes within the t-BuOH matrix at -196 deg C were investigated in order to show the utility of the matrix as a tool for the study of carbene chemistry.The photolysis of several aryldiazomethane derivatives in the t-BuOH matrix gave the olefinic dimer as the main product, probably arising from a combination of two triplet arylcarbenes in the aggregate of molecules.The similar photolysis of other diazo compounds (e.g., N2CHCOR, R = OR', NEt2, and Ph) resulted in no detection of the olefinic dimer.This was explained in terms of the structural effect on the ground-state multiplicity of carbene.The photolysis of Ph2CN2 in t-BuOH containing 5percent EtOH at -196 deg C gave almost exclusively O-H and C-H insertion products with the solute alcohol at the expense of the O-H insertion product with the host, i.e., Ph2CHOBut, which was the major product in the liquid-phase photolysis.This is ascribable to the co-aggregation of the carbene precursor with the solute alcohol because of the relatively large guest hole provided by the bulky tertiary alcohol matrix.A more general utility of this matrix was shown in the reaction of Ph2C with Ph2CO to give oxirane, in which the intervention of carbonyl ylide was demonstrated at low temperatures.
- Tomioka, Hideo,Miwa, Takaaki,Suzuki, Shinji,Izawa, Yasuji
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p. 753 - 756
(2007/10/02)
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- Effects of strong π-electron accepting substituents on structure preference for thiocarbonyl ylide or thiirane
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Equilibrium between thiocarbonyl ylide and thiirane depends upon the π-electron accepting nature of the substituents. Four carbonyl and ester groups move the equilibrium far to the thiocarbonyl ylide side.
- Oka, Kitaro,Dobashi, Akira,Hara, Shoji
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p. 3579 - 3582
(2007/10/02)
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