-
Synthesis of (E)-1-benzyl-4-benzylidenepyrrolidine-2, 3-dione: Spectroscopic Characterization and X-ray Structure Determination
Mouhamadou Fofana,
Mohamet Diop,
Cheikh Ndoye,
Grégory Excoffier,
Mohamed Gaye
Issue:
Volume 11, Issue 3, June 2023
Pages:
71-77
Received:
4 May 2023
Accepted:
18 May 2023
Published:
29 May 2023
Abstract: The compound (E)-1-benzyl-4-benzylidenepyrrolidine-2,3-dione was synthetized using Ethyl 1-benzyl-4,5-dioxopyrrolidine-3-carboxylate, and benzaldehyde in Ethanol/HCl medium. The isolated compound was characterized by elemental analyses, 1H and 13C NMR and FTIR spectroscopy. Suitable crystal for X-ray diffraction was obtained from slow evaporation of a solution of the compound in ethyl acetate. The compound crystallizes in the centrosymmetric space group P-1 of the triclinic system with the following unit cell parameters a = 6.4367 (4) Å, b = 7.4998 (5) Å, c = 15.3455 (5) Å, = 86.448 (4)°, β = 78.732 (4)°, = 83.943 (5)°, V = 721.80 (7) Å3, Z = 2, R1 = 0.049 and wR2 = 0.135. In the title molecule, C18H15NO2, the pyrrolidine-2,3-dione ring is almost planar (r.m.s. deviation = 0.0081 Å). The pyrrolidine ring has an envelope conformation with a methylene carbon as the flap. The two phenyl rings are severely twisted with dihedral angle of 72.234 (5)°. The pyrrolidine ring is quite coplanar with the C13-C18 phenyl ring and severely twisted from the C1-C6 phenyl ring with dihedral angles of 0.762 (5)° and 72.750 (5)°. The molecule adopts an E configuration with respect to the ethylenic moiety. Unclassical C—H•••O hydrogen bonding link the molecules, forming layers in the bc plane.
Abstract: The compound (E)-1-benzyl-4-benzylidenepyrrolidine-2,3-dione was synthetized using Ethyl 1-benzyl-4,5-dioxopyrrolidine-3-carboxylate, and benzaldehyde in Ethanol/HCl medium. The isolated compound was characterized by elemental analyses, 1H and 13C NMR and FTIR spectroscopy. Suitable crystal for X-ray diffraction was obtained from slow evaporation o...
Show More
-
Study of the Quantitative Structure Activity Relationship (QSAR) of a Series of Molecules Derived from Thioureas with Anticancer Activities in the Liver
Doumbia Siriki,
Dembele Georges Stephane,
Tuo Nanou Tieba,
Konate Bibata,
Kodjo Charles,
Ziao Nahosse
Issue:
Volume 11, Issue 3, June 2023
Pages:
78-87
Received:
9 May 2023
Accepted:
27 May 2023
Published:
9 June 2023
Abstract: The study of the quantitative structure activity relationship (QSAR) of liver cancer was carried out using a series of twenty-five (25) molecules derived from thioureas. The molecular descriptors were obtained after optimization of all these molecules at the B3LYP/6-31+ G (d, p) computational level. The multiple linear regression (MLR) method was used to carry out this study. The use of this method has thus made it possible to obtain a model from the molecular descriptors that are the lipophilicity LogP, the bond lengths d(C=N2) and d(N2-Cphen1), the vibration frequency υ (C =O) and the number of atoms. The results of the statistical indicators obtained from the model (R2=0.906; RMCE=0.198; F= 21.170), allow us to say that this model is acceptable, robust and has good predictive power. Also, the vibration frequency of the carbon-oxygen double bond (C=O), the length of the C-N2 bond and the lipophilicity (LogP) were found to be the priority descriptors in the prediction of the anticancer activity of the liver. Moreover, all the criteria of Tropsha et al. were verified by our model. Moreover, the analysis of the domain of applicability of this model shows that a prediction of the anticancer activity of new derivatives of thiourea is acceptable when its leverage value is less than 1.06, otherwise the anticancer activity of the liver of this compound could not be reliably predicted.
Abstract: The study of the quantitative structure activity relationship (QSAR) of liver cancer was carried out using a series of twenty-five (25) molecules derived from thioureas. The molecular descriptors were obtained after optimization of all these molecules at the B3LYP/6-31+ G (d, p) computational level. The multiple linear regression (MLR) method was u...
Show More
-
Modelling Interactions Between Flavanols and Amine Acids: Case of Catechin and Epicatechin with Alanine; NBO, AIM, NCI Analysis
Essoh Akpa Eugene,
N’Guessan Boka Robert,
Adenidji Ganiyou,
Adjou Ane,
Bamba El Hadji Sawaliho
Issue:
Volume 11, Issue 3, June 2023
Pages:
88-107
Received:
10 May 2023
Accepted:
29 May 2023
Published:
9 June 2023
Abstract: The interactions between two flavanols (Catechin and Epicatechin) and (Ala) Alanine (aliphatic amino acid) are evaluated by theoretical chemistry methods. Calculations at the level DFT/B3LYP/6-31+G (d, p) determine their characteristics and those of the monomers. Geometric, energetic, and spectroscopic parameters in addition to QTAIM (Quantum Theory of Atoms In Molecules), NBO (Natural Bond Orbital) and NCI (Non-Covalent Interaction) topological analyses qualify the nature and type of these. The results indicate that the main interactions are O–H⋯O and O–H⋯N between the hydroxyl groups of Cat (Catechin) or Epicat (Epicatechin) and the heteroatoms of Ala. They mention the existence of a secondary one alongside the main. They classify them into proper, improper, moderate, and weak. The spectroscopic parameters prove that O–H⋯O, O–H⋯N and N–H⋯O are proper. They establish that the C–H⋯N and C–H⋯O are improper. QTAIM analysis presents O–H⋯O, O–H⋯N interactions as moderate and C–H⋯O and N–H⋯O as weak. Stabilization energies show that the most reactive sites of Ala Nsp3 and Osp2 interact strongly with the O28–H29, O32–H33 and O34–H35 hydroxyl groups of EpiCat and Cat. These interactions lead to the most stable complexes. This research reveals the existence of the VDW (Van Der Walls) NCI type and repulsive (steric) interactions in these complexes.
Abstract: The interactions between two flavanols (Catechin and Epicatechin) and (Ala) Alanine (aliphatic amino acid) are evaluated by theoretical chemistry methods. Calculations at the level DFT/B3LYP/6-31+G (d, p) determine their characteristics and those of the monomers. Geometric, energetic, and spectroscopic parameters in addition to QTAIM (Quantum Theor...
Show More
-
Concerted [2+2] Oxidative-Cycloadition-Cycloreversion versus Cyclopropanation Reactions at M-carbene Center
Issue:
Volume 11, Issue 3, June 2023
Pages:
108-136
Received:
20 May 2023
Accepted:
13 June 2023
Published:
27 June 2023
Abstract: The selectivity of olefin metathesis catalyzed by metal-alkylidene LnM=CHR, a reversible sequence of concerted [2+2] oxidative-cycloadition-cycloreversion at metal center, which fits to π–CAM (Complex Assisted Metathesis) principle or π-bond mode, in other words a transalkylidenation reaction through a metallacyclobutane intermediate, as well as the cyclopropanation reactions depends mostly on the structure of the catalysts. Cyclopropane affords as side product in the presence of the Schrock or Grubbs metal carbene complex which alternatively decomposed through β-hydride transfer, or as the major product in the presence of the Fischer carbene complex. The cyclopropnanation mechanisms are concerted or stepwise. The insertion of the transition-metal atom into a C-C bond of cyclopropane is predicted to form MCH2 + C2H4, through a formal retrocarbene addition, a reverse reaction cyclopropane – metallacyclobutane. Five resonance structures are representative for the metal-carbon bond of alkylidene complexes: 1. ethylene, corresponding to the singlet coupling of a neutral species, 2. π ylide, corresponding to a covalent M-C σ bond and a dative carbon to metal π-back bond, 3. as a dative carbon to metal σ-bond coupled with a dative to carbon π-back bond, corresponding to the singlet-carbene model of bonding, 4. as a four-electron donor corresponding to coordination of the CH22- ligand to a LnMq+2 fragment in a ionic fashion, and 5. σ ylide, corresponding to a dative M-C σ bond coupled with a covalent M-C π bond. The reactivity of the M-carbene depends on the predominance of one resonance structure over the other, therefore the nucleophilic resonance (LnMq+CH2q-) contribute approximately 50% to the ground-state wave function, the neutral resonance structures (LnM0CH20) 45%, and the electrophilic resonance structures (LnMq-CH2q+) 5%. The bonding situation, derived from the contribution of the electrostatic and the orbital interaction, the strength of the σ donor and π acceptor bonding, was discussed in terms of well-defined quantum chemical methods.
Abstract: The selectivity of olefin metathesis catalyzed by metal-alkylidene LnM=CHR, a reversible sequence of concerted [2+2] oxidative-cycloadition-cycloreversion at metal center, which fits to π–CAM (Complex Assisted Metathesis) principle or π-bond mode, in other words a transalkylidenation reaction through a metallacyclobutane intermediate, as well as th...
Show More
