The reaction of malononitrile with some β-dicarbonyl compounds

1975 ◽  
Vol 28 (3) ◽  
pp. 581 ◽  
Author(s):  
JW Ducker ◽  
MJ Gunter
Keyword(s):  
Benzene Solution ◽  
Similar Reaction ◽  
Benzene Derivatives ◽  
Dicarbonyl Compounds ◽  
Keto Esters

The reaction of β-keto esters and amides with malononitrile, in the presence of alcohol, has been shown to proceed through cyanocarbon acid and iminopyran intermediates to yield the pyridones (3).With β- diketones, in benzene solution, a similar reaction is accompanied by the formation of δ-lactams(15) and benzene derivatives (16).

Pyridinium ylids in synthesis. II. Acylation and the synthesis of b-dicarbonyl compounds

1967 ◽  
Vol 20 (11) ◽  
pp. 2455 ◽  
Author(s):  
CA Henrick ◽  
E Ritchie ◽  
WC Taylor
Keyword(s):  
Acid Chlorides ◽  
Dicarbonyl Compounds ◽  
Keto Esters

The acylation of N-pyridinium ylids with acid chlorides or anhydrides yields C-acylated ylids which may be reductivaly cleared to yield P-diketones or P-keto esters, depending on the starting materials. The u.v., i.r., and N.M.R. spectra of the ylids are discussed.

scholarly journals Effect of Reactivity on Kinetics and a Mechanistic Investigation of the Reaction between Dimethyl Acetylenedicarboxylate and 1,3-Dicarbonyl Compounds in the Presence of a Catalyst: A Spectrophotometric Approach

2018 ◽  
Vol 43 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Mahdieh Darijani ◽  
Sayyed Mostafa Habibi-Khorassani ◽  
Mehdi Shahraki
Keyword(s):  
Structural Effect ◽  
Similar Reaction ◽  
Dimethyl Acetylenedicarboxylate ◽  
Dicarbonyl Compounds ◽  
Dicarbonyl Compound ◽  
Rate Determining Step ◽  
Mechanistic Investigation ◽  
Differential Behaviour ◽  
Fourth Step ◽  
Step Step

A kinetic and mechanistic investigation, using conventional UV-Vis spectrophotometry, of the reaction between dimethyl acetylenedicarboxylate (DMAD) and 1,3-dicarbonyl compounds including acetylacetone (ACAC) and dibenzoylmethane (DBM), has been conducted in a methanol environment with triphenylarsine (TPA) acting as a catalyst. Previously, in a similar reaction, triphenylphosphine (TPP) (instead of TPA) had been employed as a reactant (not a catalyst) for the generation of an ylide (final product). In the present work, of significance is the differential behaviour of TPA which, as a catalyst in the reaction environment, leads to a cyclopropane compound. Of other significance is the different behaviours of the two reactants in the kinetics and mechanism of the reaction. In previous work, TPP acted as a weak nucleophile (a reactant), so the first step of the reaction was recognised as the rate-determining step (RDS). Here, TPA reacts as a stronger nucleophile and a catalyst, resulting in the fourth step of the reaction (step4, k4, a proton transfer process) being recognised as the RDS. The reaction followed second-order kinetics. The proposed mechanism was adapted in accord with the experimental results and the steady-state assumption. The results showed that the reaction rate decreases in the presence of DBM, which participates in the second step (step2), compared to ACAC when it is present as another 1,3-dicarbonyl compound (structural effect). In addition, in previous work, the partial order of the reaction with respect to the 1,3-dicarbonyl compound was zero, while it is one in the present work. As a significant result, not only did a change in the structure of one of the reactants (TPA instead of TPP) create a different product, but also the kinetics and reaction mechanism changed. In addition, the reaction is enthalpy-controlled.

Rhenium- and manganese-catalyzed carbon–carbon bond formation using 1,3-dicarbonyl compounds and alkynes

2010 ◽  
Vol 82 (7) ◽  
pp. 1491-1501 ◽  
Author(s):  
Yoichiro Kuninobu ◽  
Atsushi Kawata ◽  
Salprima S. Yudha ◽  
Hisatsugu Takata ◽  
Mitsumi Nishi ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Catalytic Amount ◽  
Alder Reaction ◽  
Terminal Alkynes ◽  
Dicarbonyl Compounds ◽  
Keto Esters ◽  
Rhenium Complex ◽  
Diels Alder Reaction ◽  
Carbon Carbon Bond ◽  
Catalyzed Reactions

A rhenium complex, [ReBr(CO)3(thf)]2, catalyzed insertion of terminal alkynes into a C–H bond of active methylene sites of 1,3-dicarbonyl compounds. When a catalytic amount of isocyanide or molecular sieves was added to the reaction mixture, the reaction course changed markedly, and insertion of alkynes into a C–C single bond between α- and β-positions of cyclic and acyclic β-keto esters occurred. The formed acyclic δ-keto esters could be converted to 2-pyranones, which were applied to the synthesis of multisubstituted aromatic compounds via the Diels–Alder reaction and successive elimination of carbon dioxide. In the case of the rhenium-catalyzed reactions between terminal alkynes and β-keto esters without substituent at the α-position, tetrasubstituted benzenes were produced regioselectively by two-to-one reaction of the components. The yields of tetrasubstituted benzenes were improved by using a manganese catalyst.

Highly Enantioselective Michael Addition of Cyclic 1,3-Dicarbonyl Compounds to β,γ-Unsaturated α-Keto Esters

2010 ◽  
Vol 352 (10) ◽  
pp. 1648-1652 ◽  
Author(s):  
Xing-Kuan Chen ◽  
Chang-Wu Zheng ◽  
Sheng-Li Zhao ◽  
Zhuo Chai ◽  
Ying-Quan Yang ◽  
...  
Keyword(s):  
Michael Addition ◽  
Dicarbonyl Compounds ◽  
Keto Esters

The Retro-Michael Reaction of 1,5-Dicarbonyl Compounds: Scope and Limitation

1999 ◽  
Vol 64 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Jian-Xin Wang ◽  
Tong-Shuang Li
Keyword(s):  
Good Yield ◽  
Steam Distillation ◽  
Michael Reaction ◽  
Glass Wool ◽  
Dicarbonyl Compounds ◽  
Keto Esters ◽  
Tricyclic Compounds ◽  
Keto Acids

Under catalysis of NaOH or KOH adsorbed on glass wool and by using steam distillation, (20R,S)-4,4,5,14-tetramethyl-18,19-dinor-13,17-seco-5β,8α,9β,10α,14β-cholestane-13,17-dione (1) and 3,14-dioxo-14,15-seco-5α-cholestan-15-al (4) gave good yield (>59%) of the corresponding tricyclic compounds (8a, 8b and 10a) via a retro-Michael reaction at 250 °C. While 5-oxo-4-nor-3,5-secocholestan-3-oic acid (6) and ethyl 5-oxo-4-nor-3,5-secocholestan-3-oate (7) afforded low yield (<15%) of the retro-Michael cleavage products (12a, 12b) at the same conditions. Thus, the retro-Michael reaction worked well for 1,5-diketones and 1,5-keto aldehydes but gave poor yield for 1,5-keto esters and 1,5-keto acids.

Formation of quaternary centres via iron allyl cations. Rapid entry into spirocyclic ring systems

1997 ◽  
Vol 75 (7) ◽  
pp. 965-974 ◽  
Author(s):  
M. Anne Charlton ◽  
James R. Green
Keyword(s):  
Reductive Cyclization ◽  
Cyclization Reactions ◽  
Dicarbonyl Compounds ◽  
Enol Ethers ◽  
Ring Systems ◽  
Silyl Enol Ethers ◽  
Keto Esters ◽  
Condensation Products ◽  
Ketene Acetals ◽  
Silyl Ketene Acetals

Ester-substituted allyltetracarbonyliron cations react with cycloalkylidene-type silyl enol ethers, silyl ketene acetals, and β-keto-esters to give 1,6-dicarbonyl compounds containing a newly formed quaternary centre. Selected condensation products are converted by enolate chemistry into spirocyclic [4.4], [4.5], and [4.6] systems. Acyloin and other reductive cyclization reactions are employed to convert the condensation products into spirocyclic [4.5], [5.5], and [5.6] systems. Keywords: allyliron complexes, umpolung synthesis, 1,6-dicarbonyls, spirocycle synthesis.

Catalytic asymmetric α-amination of β-keto esters and β-keto amides with a chiral N,N′-dioxide–copper(i) complex

2016 ◽  
Vol 3 (7) ◽  
pp. 809-812 ◽  
Author(s):  
Xiao Xiao ◽  
Lili Lin ◽  
Xiangjin Lian ◽  
Xiaohua Liu ◽  
Xiaoming Feng
Keyword(s):  
Reaction Conditions ◽  
Dicarbonyl Compounds ◽  
Keto Esters ◽  
Highly Efficient ◽  
Catalytic Asymmetric

The highly efficient asymmetric α-amination of β-keto esters and β-keto amides was realized by using a chiral N,N′-dioxide/Cu(i) complex. Under mild reaction conditions, a series of chiral α-amino dicarbonyl compounds were obtained in good result.

scholarly journals DMAP-Catalyzed Reaction of Diethyl 1,3-Acetonedicarboxylate with 2-Hydroxybenzylideneindenediones: Facile Synthesis of Fluorenone-Fused Coumarins

Synlett ◽  
2021 ◽  
Author(s):  
Mohanad Shkoor ◽  
Raghad Bayari
Keyword(s):  
Natural Product ◽  
Single Step ◽  
Facile Synthesis ◽  
Dicarbonyl Compounds ◽  
Keto Esters

AbstractThe base-catalyzed reaction of diethyl 1,3-acetonedicarboxylate with 2-hydroxybenzylidene indenediones was studied. The reaction provides a facile and expeditious protocol for the synthesis of natural product inspired fluorenone-fused coumarins in good to very good yields. This process resembles a combination of domino Michael–intramolecular Knoevenagel–aromatization–lactonization reactions in a single step. Although this reaction operates with many bases, the best yields were obtained with DMAP as a catalyst. This protocol could open new potential avenues for the synthesis of fused coumarins by the reaction of substituted β-keto esters with different 2-(2-hydroxybenzylidenes) of 1,3-dicarbonyl compounds.

scholarly journals Monoallylation and benzylation of dicarbonyl compounds with alcohols catalysed by a cationic cobalt(iii) compound

RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9235-9245
Author(s):  
Mohan Chandra Sau ◽  
Smita Mandal ◽  
Manish Bhattacharjee
Keyword(s):  
Dicarbonyl Compounds ◽  
Benzylic Alcohols ◽  
Keto Esters

Monoallylation and monoalkylation of diketones and β-keto esters with allylic and benzylic alcohols catalysed by [Cp*Co(CH3CN)3][SbF6]2 (I) are reported.

Dichlorination of α-Diazo-β-dicarbonyls Using (Dichloroiodo)benzene

Synlett ◽  
2015 ◽  
Vol 26 (08) ◽  
pp. 1003-1007 ◽  
Author(s):  
Graham Murphy ◽  
Keith Coffey
Keyword(s):  
Lewis Acid ◽  
Relative Stability ◽  
Reaction Rates ◽  
Diazo Compounds ◽  
Acid Activation ◽  
Chlorination Reaction ◽  
Dicarbonyl Compounds ◽  
Keto Esters ◽  
First Time

α-Diazo-β-dicarbonyl compounds were chlorinated using (dichloro)iodobenzene and an activating catalyst. A broad range of reaction rates was observed, which paralleled the relative stability/nucleo­philicity of the diazo compounds. Acyclic diazocarbonyls reacted faster than cyclics, and β-diketones were much faster to react than β-keto esters or β-diesters. Lewis acid activation was used for the first time, allowing us to overcome instances of poor chemoselectivity. Though the yields ranged from low to good, this chlorination reaction has again proven a mild and effective halogenation strategy.

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