Squaric acid as an impressive organocatalyst for Michael addition in water

Azizi, Najmedin; Saki, Elham; Edrisi, Mahtab

doi:10.1016/j.crci.2011.07.003

Cited by 22 publications

(18 citation statements)

References 62 publications

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“…The 1,4-conjugate addition of primary and secondary aniline derivative to various Michael acceptor motifs has been widely reported [ [43] , [44] , [45] , [46] , [47] , [48] , [49] ], including related natural product derived lactones [ 38 , 41 , 43 , 44 , 50 ] that have been shown to be amenable to Lewis or Brønsted acid catalysed conjugate addition of anilines. In order to extend the scope of such aniline derivative additions to parthenolide ( 1 ) a series of model, precedent-informed, reactions were investigated.…”

Section: Resultsmentioning

confidence: 99%

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Aniline-containing derivatives of parthenolide: Synthesis and anti-chronic lymphocytic leukaemia activity

Quy

Male

et al. 2020

Tetrahedron

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Parthenolide exhibits anti-leukaemia activity, whilst its synthetic modification to impart improve drug-like properties, including 1,4-conjugate addition of primary and secondary amines, have previously been used, 1,4-addition of aniline derivatives to parthenolide has not been fully explored. A protocol for such additions to parthenolide is outlined herein. Reaction conditions were determined using tulipane as a model Michael acceptor. Subsequently, aniline-containing parthenolide derivatives were prepared under the optimised conditions and single crystal X-ray diffraction structures were resolved for three of the compounds synthesised. The synthesised derivatives, along with compounds resulting from a side reaction, were tested for their in vitro anti-leukaemia activity using the chronic lymphocytic leukaemia (CLL) MEC1 cell line. Computational studies with the 2RAM protein structure suggested that the activity of the derivatives was independent of their in silico ability to dock with the Cys38 residue of NF-κB.

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Section: Resultsmentioning

confidence: 99%

“…Azizi et al . showed that squaric acid was an excellent organocatalyst for the addition of aromatic amines (and thiols) to Michael acceptors under aqueous conditions [ 46 ]. The formation of 6 under control of squaric acid as catalyst (10 mol%) in water at room temperature proceeded in 39% yield ( Table 1 , entry 12).…”

Section: Resultsmentioning

confidence: 99%

Aniline-containing derivatives of parthenolide: Synthesis and anti-chronic lymphocytic leukaemia activity

Quy

Male

et al. 2020

Tetrahedron

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“…[34][35] The oxocarbon acids are very relevant materials in organic reactivity studies. 36 The good results obtained for the structural properties of these materials in the previous work 6 encouraged the determination of their mechanical properties. These acids in the solid state were shown to display negative Poisson ratios (NPR).…”

Section: Introductionmentioning

confidence: 88%

Thermodynamic, Raman Spectroscopic, and UV–Visible Optical Characterization of the Deltic, Squaric, and Croconic Cyclic Oxocarbon Acids

Colmenero

Escribano

2019

J. Phys. Chem. A

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A precise and complete thermodynamic, Raman spectroscopic and ultraviolet-visible optical characterization of the deltic, squaric and croconic cyclic oxocarbon acids is obtained using theoretical solid-state methods employing very demanding calculation parameters. The computed fundamental thermodynamic properties include the isobaric specific heat, the entropy, the enthalpy and the Gibbs free energy as a function of temperature. The calculated specific heats at 298.15 K of the deltic, squaric and croconic acids are 89.7, 111.2 and 133.2 J • mol −1 • K −1 , respectively, and the corresponding entropies are 98.3, 117.3 and 136.5 J • mol −1 • K −1 . The only value of these properties known from experimental measurements is the specific heat of the squaric acid which differs from the computed value at 315 K by about 4.9%. The calculated values of the thermodynamic properties are then used to determine the thermodynamic properties of formation of these materials in terms of the elements. As an application of the calculated thermodynamic properties of formation, the Gibbs free energies of reaction and associated reaction constants are evaluated for the reactions of thermal decomposition and complete combustion of the squaric and croconic acids and the reaction of interconversion between them. The only available experimental values of these properties, namely the enthalpies of combustion of squaric and croconic acids at room temperature, are reproduced theoretically with high accuracy. The Raman spectra of these materials are also computed using Density Functional Perturbation Theory. The analysis of the theoretical Raman spectra of these materials points out to significant differences with respect to their usual empirical assignment. Therefore, the Raman spectra of these materials is fully reassigned. Finally, the ultraviolet-visible (UV-Vis) optical properties of the deltic, squaric and croconic acids are computed. The UV-Vis absorption spectrum of the croconic acid in the spectral region 225-425 nm and the UV absorption spectrum of the squaric acid in the region 200-350 nm which had previously been measured experimentally are well reproduced. The corresponding spectrum for the deltic acid and the reflectivity, optical conductivity, dielectric, refractive index and loss optical functions of the three materials, which had never been published as far as we know, are reported as a function of the wavelength of incident radiation in the range 200-750 nm. The origin of the peaks in the absorption spectra which had not been analyzed so far is unveiled here by examining the inter-band electronic transitions in these materials.their reactions of complete combustion:and the reaction of conversion between them in the presence of carbon monoxide: (E) H 2 C 4 O 4 (cr) + CO(g) → H 2 C 5 O 5 (cr) as a function of temperature. The thermodynamic parameters of organic compounds are extraordinarily important not only in

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“…Due to our interest in developing new green media for organic syntheses [21][22][23][24][25], herein we describe a onepot, three-component passerini reaction in DES as a green solvent and catalyst for -acyloxycarboxamides synthesis. Furthermore, the isolation and puri cation steps of this DES are very simple and easy.…”

Section: Resultsmentioning

confidence: 99%

Nano-ordered MCM-41-SO3H an efficient catalyst for the synthesis of N-substituted pyrroles in water

2016

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Squaric acid as an impressive organocatalyst for Michael addition in water

Cited by 22 publications

References 62 publications

Aniline-containing derivatives of parthenolide: Synthesis and anti-chronic lymphocytic leukaemia activity

Aniline-containing derivatives of parthenolide: Synthesis and anti-chronic lymphocytic leukaemia activity

Thermodynamic, Raman Spectroscopic, and UV–Visible Optical Characterization of the Deltic, Squaric, and Croconic Cyclic Oxocarbon Acids

Nano-ordered MCM-41-SO3H an efficient catalyst for the synthesis of N-substituted pyrroles in water

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