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Mukhopadhyay J, Bhagat S, Sahoo SC, Bharatam PV. L→S Coordination Complexes Containing Benzothiazol-2-ylidene Ligand: Quantum Chemical Analysis and Synthesis. Chempluschem 2024:e202400150. [PMID: 38554142 DOI: 10.1002/cplu.202400150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 03/29/2024] [Accepted: 03/29/2024] [Indexed: 04/01/2024]
Abstract
(NHC)→E coordination interactions were known where NHC is an N-heterocyclic carbene, and E is a main group element (B, C, N, Si, P). Recently, it was suggested that compounds with (NHC)→S coordination chemistry are also possible. This work reports quantum chemical analysis and synthesis of (NHC)→S-R(+) complexes in which benzothiazol-2-ylidene acts as a ligand. A Density functional study established that (NHC)→S interaction can best be described as a coordination interaction. Synthetic efforts were made, initially, to generate divalent sulfur compounds containing benzothiazole substituents. N-alkylation of the heterocyclic ring in these sulfides using methyl triflate led to the generation of the desired products with (NHC)→S coordination chemistry, which involves the in situ generation of NHC ring ligands. The observed changes in the 13C NMR spectra, before and after methylation, confirmed the change in the electronic character of the C-S bond from a covalent character to a coordination character.
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Affiliation(s)
- Joy Mukhopadhyay
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S., Nagar, Punjab, 160062, India
| | - Srikant Bhagat
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S., Nagar, Punjab, 160062, India
| | - Subash C Sahoo
- Department of Chemistry, Panjab University, Sector 14, Chandigarh, 160014, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S., Nagar, Punjab, 160062, India
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2
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Jabłoński M. Halogen Bond to Experimentally Significant N-Heterocyclic Carbenes (I, IMe 2, I iPr 2, I tBu 2, IPh 2, IMes 2, IDipp 2, IAd 2; I = Imidazol-2-ylidene). Int J Mol Sci 2023; 24:ijms24109057. [PMID: 37240403 DOI: 10.3390/ijms24109057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
The subjects of the article are halogen bonds between either XCN or XCCH (X = Cl, Br, I) and the carbene carbon atom in imidazol-2-ylidene (I) or its derivatives (IR2) with experimentally significant and systematically increased R substituents at both nitrogen atoms: methyl = Me, iso-propyl = iPr, tert-butyl = tBu, phenyl = Ph, mesityl = Mes, 2,6-diisopropylphenyl = Dipp, 1-adamantyl = Ad. It is shown that the halogen bond strength increases in the order Cl < Br < I and the XCN molecule forms stronger complexes than XCCH. Of all the carbenes considered, IMes2 forms the strongest and also the shortest halogen bonds with an apogee for complex IMes2⋯ICN for which D0 = 18.71 kcal/mol and dC⋯I = 2.541 Å. In many cases, IDipp2 forms as strong halogen bonds as IMes2. Quite the opposite, although characterized by the greatest nucleophilicity, ItBu2 forms the weakest complexes (and the longest halogen bonds) if X ≠ Cl. While this finding can easily be attributed to the steric hindrance exerted by the highly branched tert-butyl groups, it appears that the presence of the four C-H⋯X hydrogen bonds may also be of importance here. Similar situation occurs in the case of complexes with IAd2.
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Affiliation(s)
- Mirosław Jabłoński
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Torun, Poland
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3
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Wanjari PJ, Rath A, Sathe RY, Bharatam PV. Identification of CYP3A4 inhibitors as potential anti-cancer agents using pharmacoinformatics approach. J Mol Model 2023; 29:156. [PMID: 37097473 DOI: 10.1007/s00894-023-05538-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/30/2023] [Indexed: 04/26/2023]
Abstract
Biguanide derivatives exhibit a wide variety of therapeutic applications, including anti-cancer effects. Metformin is an effective anti-cancer agent against breast cancer, lung cancer, and prostate cancer. In the crystal structure (PDB ID: 5G5J), it was found that metformin is found in the active site of CYP3A4, and the associated anti-cancer effect was explored. Taking clues from this work, pharmacoinformatics research has been carried out on a series of known and virtual biguanide, guanylthiourea (GTU), and nitreone derivatives. This exercise led to the identification of more than 100 species that exhibit greater binding affinity toward CYP3A4 in comparison to that of metformin. Selected six molecules were subjected to molecular dynamics simulations, and the results are presented in this work.
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Affiliation(s)
- Pravin J Wanjari
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar-160062, Punjab, India
| | - Asutosh Rath
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar-160062, Punjab, India
| | - Rohit Y Sathe
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar-160062, Punjab, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar-160062, Punjab, India.
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Yao S, Saddington A, Xiong Y, Driess M. Chelating Bis-silylenes As Powerful Ligands To Enable Unusual Low-Valent Main-Group Element Functions. Acc Chem Res 2023; 56:475-488. [PMID: 36720115 DOI: 10.1021/acs.accounts.2c00763] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
ConspectusSilylenes are divalent silicon species with an unoccupied 3p orbital and one lone pair of electrons at the SiII center. Owing to the excellent σ-donating ability of amidinato-based silylenes, which stems from the intramolecular imino-N donor interaction with the vacant 3p orbital of the silicon atom, N-heterocyclic amidinato bis(silylenes) [bis(NHSi)s] can serve as versatile strong donating ligands for cooperative stabilization of central atoms in unusually low oxidation states. Herein, we present our recent achievement on the application of bis(NHSi) ligands with electronically and spatially different spacers to main-group chemistry, which has allowed the isolation of a variety of low-valent compounds consisting of monatomic zero-valent group 14 E0 complexes (named "metallylones", E = Si, Ge, Sn, Pb); monovalent group 15 EI complexes (E = N, P, isoelectronic with metallylones); and diatomic low-valent E2 complexes (E = Si, Ge, P) with intriguing electronic structures and chemical reactivities.The role of the SiII···SiII distance was revealed to be crucial in this chemistry. Utilizing the pyridine-based bis(NHSi) (Si···Si distance: 7.8 Å) ligand, germanium(0) complexes with additional Fe(CO)4 protection at the Ge0 site have been isolated. Featuring a shorter Si···Si distance of 4.3 Å, the xanthene-based bis(NHSi) has allowed the realization of the full series of heavy zero-valent group 14 element E0 complexes (E = Si, Ge, Sn, Pb), while the o-carborane-based bis(NHSi) (Si···Si distance: 3.3 Å) has enabled the isolation of Si0 and Ge0 complexes. Remarkably, reduction of the o-carborane-based bis(NHSi)-supported Si0 and Ge0 complexes induces the movement of two electrons into the o-carborane core and provides access to SiI-SiI and GeI-GeI species as oxidation products. Additionally, the o-carborane-based bis(NHSi) reacts with adamantyl azide, leading to a series of nitrogen(I) complexes as isoelectronic species of a carbone (C0 complex). Moreover, cooperative activation of white phosphorus gives bis(NHSi)-supported phosphorus complexes with varying and unexpected electronic structures when employing the xanthene-, o-carborane-, and aniline-based bis(NHSi)s. With the better kinetic protection provided by the xanthene-based bis(NHSi), small-molecule activation and functionalization of the bis(NHSi)-supported central E or E2 atoms (E = Si, Ge, P) are possible and furnish several novel functionalized silicon, germanium, and phosphorus compounds.With knowledge of the ability of chelating bis(NHSi)s in coordinating and functionalizing low-valent group 14 and 15 elements, the application of these ligand systems to other main-group elements such as group 2 and 13 is quite promising. To fully understand the role of the NHSi in a bis(NHSi) ligand, introducing a mixed ligand, i.e., the combination of an NHSi with other functional groups, such as Lewis acidic borane or Lewis basic borylene, in one chelating ligand could lead to new types of low-valent main-group species. Furthermore, the development of a genuine acyclic silylene, without an imino-N interaction with the vacant 3p orbital at the silicon(II) atom, as part of a chelating bis(acyclic silylene) has the potential to form very electronically different main-group element complexes that could achieve even more challenging bond activations such as N2 or unactivated C-H bonds.
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Affiliation(s)
- Shenglai Yao
- Technische Universität Berlin, Department of Chemistry: Metalorganics and Inorganic Materials, Sekr. C2, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Artemis Saddington
- Technische Universität Berlin, Department of Chemistry: Metalorganics and Inorganic Materials, Sekr. C2, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Yun Xiong
- Technische Universität Berlin, Department of Chemistry: Metalorganics and Inorganic Materials, Sekr. C2, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Matthias Driess
- Technische Universität Berlin, Department of Chemistry: Metalorganics and Inorganic Materials, Sekr. C2, Strasse des 17. Juni 135, 10623 Berlin, Germany
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Nature of Beryllium, Magnesium, and Zinc Bonds in Carbene⋯MX 2 (M = Be, Mg, Zn; X = H, Br) Dimers Revealed by the IQA, ETS-NOCV and LED Methods. Int J Mol Sci 2022; 23:ijms232314668. [PMID: 36498996 PMCID: PMC9738500 DOI: 10.3390/ijms232314668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
The nature of beryllium−, magnesium− and zinc−carbene bonds in the cyclopropenylidene⋯MX2 (M = Be, Mg, Zn; X = H, Br) and imidazol-2-ylidene⋯MBr2 dimers is investigated by the joint use of the topological QTAIM-based IQA decomposition scheme, the molecular orbital-based ETS-NOCV charge and energy decomposition method, and the LED energy decomposition approach based on the state-of-the-art DLPNO-CCSD(T) method. All these methods show that the C⋯M bond strengthens according to the following order: Zn < Mg << Be. Electrostatics is proved to be the dominant bond component, whereas the orbital component is far less important. It is shown that QTAIM/IQA underestimates electrostatic contribution for zinc bonds with respect to both ETS-NOCV and LED schemes. The σ carbene→MX2 donation appears to be much more important than the MX2→ carbene back-donation of π symmetry. The substitution of hydrogen atoms by bromine (X in MX2) strengthens the metal−carbene bond in all cases. The physical origin of rotational barriers has been unveiled by the ETS-NOCV approach.
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Wanjari PJ, Saha N, Dubey G, Bharatam PV. Metal-free methods for the generation of benzimidazoles and 2-aminobenzimidazoles. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.133143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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7
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Jabłoński M. On the Coexistence of the Carbene⋯H-D Hydrogen Bond and Other Accompanying Interactions in Forty Dimers of N-Heterocyclic-Carbenes (I, IMe 2, I iPr 2, I tBu 2, IMes 2, IDipp 2, IAd 2; I = imidazol-2-ylidene) and Some Fundamental Proton Donors (HF, HCN, H 2O, MeOH, NH 3). Molecules 2022; 27:molecules27175712. [PMID: 36080481 PMCID: PMC9457876 DOI: 10.3390/molecules27175712] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/25/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
The subject of research is forty dimers formed by imidazol-2-ylidene (I) or its derivative (IR2) obtained by replacing the hydrogen atoms in both N-H bonds with larger important and popular substituents of increasing complexity (methyl = Me, iso-propyl = iPr, tert-butyl = tBu, phenyl = Ph, mesityl = Mes, 2,6-diisopropylphenyl = Dipp, 1-adamantyl = Ad) and fundamental proton donor (HD) molecules (HF, HCN, H2O, MeOH, NH3). While the main goal is to characterize the generally dominant C⋯H-D hydrogen bond engaging a carbene carbon atom, an equally important issue is the often omitted analysis of the role of accompanying secondary interactions. Despite the often completely different binding possibilities of the considered carbenes, and especially HD molecules, several general trends are found. Namely, for a given carbene, the dissociation energy values of the IR2⋯HD dimers increase in the following order: NH3< H2O < HCN ≤ MeOH ≪ HF. Importantly, it is found that, for a given HD molecule, IDipp2 forms the strongest dimers. This is attributed to the multiplicity of various interactions accompanying the dominant C⋯H-D hydrogen bond. It is shown that substitution of hydrogen atoms in both N-H bonds of the imidazol-2-ylidene molecule by the investigated groups leads to stronger dimers with HF, HCN, H2O or MeOH. The presented results should contribute to increasing the knowledge about the carbene chemistry and the role of intermolecular interactions, including secondary ones.
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Affiliation(s)
- Mirosław Jabłoński
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, ul. Gagarina 7, 87-100 Toruń, Poland
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8
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Bankar AA, Kathuria D. Guanylguanidines: Catalyst and Ligand for Organic Transformations. ChemistrySelect 2022. [DOI: 10.1002/slct.202201273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Affiliation(s)
- Apoorva A. Bankar
- Department of Pharmaceutical Chemistry Government College of Pharmacy, Kathora Naka Amravati Maharashtra 444604 India
| | - Deepika Kathuria
- University Center for Research and Development Chandigarh University Gharuan Punjab 140413 India
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9
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Tian J, Cordier M, Bour C, Auffrant A, Gandon V. A cyclic divalent N(I) species isoelectronic to carbodiphosphoranes. Chem Commun (Camb) 2022; 58:5741-5744. [PMID: 35466973 DOI: 10.1039/d2cc01637k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of a rare type of diphosphazenium cation is described. Its synthesis features a unique oxidative dealkylation of an iminophosphorane-phosphole by a silver(I) salt. DFT study of this compound reveals the low valent character of the N(I) center.
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Affiliation(s)
- Jiaxin Tian
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS UMR 8182, Université Paris-Saclay, Bâtiment 420, 91405 Orsay cedex, France.
| | - Marie Cordier
- Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168 Ecole Polytechnique, Institut Polytechnique de Paris, route de Saclay, 91120 Palaiseau, France.
| | - Christophe Bour
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS UMR 8182, Université Paris-Saclay, Bâtiment 420, 91405 Orsay cedex, France.
| | - Audrey Auffrant
- Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168 Ecole Polytechnique, Institut Polytechnique de Paris, route de Saclay, 91120 Palaiseau, France.
| | - Vincent Gandon
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS UMR 8182, Université Paris-Saclay, Bâtiment 420, 91405 Orsay cedex, France. .,Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168 Ecole Polytechnique, Institut Polytechnique de Paris, route de Saclay, 91120 Palaiseau, France.
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10
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Dubey G, Mahawar N, Singh T, Saha N, Sahoo SC, Bharatam PV. Thiazetidin-2-ylidenes as four membered N-heterocyclic carbenes: theoretical studies and the generation of complexes with N + center. Phys Chem Chem Phys 2022; 24:629-633. [PMID: 34933326 DOI: 10.1039/d1cp04732a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Thiazetidin-2-ylidenes have been designed as four membered N-heterocyclic carbenes (NHCs) using quantum chemical studies. These species are smaller analogs of thiazol-2-ylidenes, possess high singlet stability (57 kcal mol-1) and large nucleophilicity (3.4 eV). The possible existence of these carbenes has been established by synthesizing and crystalizing compounds with NHC→N+←(thiazetidin-2-ylidene) coordination bonds.
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Affiliation(s)
- Gurudutt Dubey
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar-160062, Punjab, India.
| | - Nutan Mahawar
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar-160062, Punjab, India.
| | - Tejender Singh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar-160062, Punjab, India.
| | - Nirjhar Saha
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar-160062, Punjab, India.
| | - Subash C Sahoo
- Department of Chemistry, Panjab University, Sector 14, Chandigarh, 160014, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar-160062, Punjab, India.
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11
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Ding Y, Sarkar SK, Nazish M, Muhammed S, Lüert D, Ruth PN, Legendre CM, Herbst‐Irmer R, Parameswaran P, Stalke D, Yang Z, Roesky HW. Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202110456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yi Ding
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
| | - Samir Kumar Sarkar
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Mohd Nazish
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | | | - Daniel Lüert
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Paul Niklas Ruth
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Christina M. Legendre
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Regine Herbst‐Irmer
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | | | - Dietmar Stalke
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Zhi Yang
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
| | - Herbert W. Roesky
- Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
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12
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Ding Y, Sarkar SK, Nazish M, Muhammed S, Lüert D, Ruth PN, Legendre CM, Herbst-Irmer R, Parameswaran P, Stalke D, Yang Z, Roesky HW. Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal. Angew Chem Int Ed Engl 2021; 60:27206-27211. [PMID: 34545990 PMCID: PMC9299049 DOI: 10.1002/anie.202110456] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Indexed: 12/01/2022]
Abstract
Herein, we report the stabilization of nitrene reagents as the source of a nitrogen atom to synthesize nitrogen‐incorporated R1LSi‐N←SiLR2 (1) [L=PhC(NtBu)2; R1=NTMS2, R2=NTMS]. Compound 1 is synthesized by reacting LSi(I)‐SiIL with 3.1 equivalents of Me3SiN3 at low temperature to afford a triene‐like structural framework. Whereas the reaction of the LSi(I)‐SiIL with 2.1 equivalents of Me3SiN3 at room temperature produced silaimine 2 with a central four‐membered Si2N2 ring which is accompanied by a silylene LSi and a cleaved silylene fragment. 1 further reacts with AgOTf at room temperature to yield compound 3 which shows coordination of nitrene to silver with the triflate salt. The compounds 1 and 2 were fully characterized by NMR, mass spectrometry, and X‐ray crystallographic analysis. The quantum mechanical calculations reveal that compounds 1 and 2 have dicoordinated monovalent N atoms having two active lone pairs of electrons. These lone pairs are stabilized by hyperconjugative interactions.
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Affiliation(s)
- Yi Ding
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany.,School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Samir Kumar Sarkar
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Mohd Nazish
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Shahila Muhammed
- National Institute of Technology Calicut, Kozhikode, 673601, India
| | - Daniel Lüert
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Paul Niklas Ruth
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Christina M Legendre
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Regine Herbst-Irmer
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | | | - Dietmar Stalke
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Zhi Yang
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China
| | - Herbert W Roesky
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
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13
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Singh T, Sahoo SC, Bharatam PV. Compound with possible N → N coordination bond: Synthesis, crystal structure and electronic structure analysis. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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14
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Jabłoński M. Study of Beryllium, Magnesium, and Spodium Bonds to Carbenes and Carbodiphosphoranes. Molecules 2021; 26:2275. [PMID: 33920004 PMCID: PMC8071025 DOI: 10.3390/molecules26082275] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/09/2021] [Accepted: 04/11/2021] [Indexed: 11/17/2022] Open
Abstract
The aim of this article is to present results of theoretical study on the properties of C⋯M bonds, where C is either a carbene or carbodiphosphorane carbon atom and M is an acidic center of MX2 (M = Be, Mg, Zn). Due to the rarity of theoretical data regarding the C⋯Zn bond (i.e., the zinc bond), the main focus is placed on comparing the characteristics of this interaction with C⋯Be (beryllium bond) and C⋯Mg (magnesium bond). For this purpose, theoretical studies (ωB97X-D/6-311++G(2df,2p)) have been performed for a large group of dimers formed by MX2 (X = H, F, Cl, Br, Me) and either a carbene ((NH2)2C, imidazol-2-ylidene, imidazolidin-2-ylidene, tetrahydropyrymid-2-ylidene, cyclopropenylidene) or carbodiphosphorane ((PH3)2C, (NH3)2C) molecule. The investigated dimers are characterized by a very strong charge transfer effect from either the carbene or carbodiphosphorane molecule to the MX2 one. This may even be over six times as strong as in the water dimer. According to the QTAIM and NCI method, the zinc bond is not very different than the beryllium bond, with both featuring a significant covalent contribution. However, the zinc bond should be definitely stronger if delocalization index is considered.
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Affiliation(s)
- Mirosław Jabłoński
- Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Toruń, Poland
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15
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Kathuria D, Raul AD, Wanjari P, Bharatam PV. Biguanides: Species with versatile therapeutic applications. Eur J Med Chem 2021; 219:113378. [PMID: 33857729 DOI: 10.1016/j.ejmech.2021.113378] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 12/18/2022]
Abstract
Biguanides are compounds in which two guanidine moieties are fused to form a highly conjugated system. Biguanides are highly basic and hence they are available as salts mostly hydrochloride salts, these cationic species have been found to exhibit many therapeutic properties. This review covers the research and development carried out on biguanides and accounts the various therapeutic applications of drugs containing biguanide group-such as antimalarial, antidiabetic, antiviral, anticancer, antibacterial, antifungal, anti-tubercular, antifilarial, anti-HIV, as well as other biological activities. The aim of this review is to compile all the medicinal chemistry applications of this class of compounds so as to pave way for the accelerated efforts in finding the drug action mechanisms associated with this class of compounds. Importance has been given to the organic chemistry of these biguanide derivatives also.
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Affiliation(s)
- Deepika Kathuria
- University Center for Research and Development, Chandigarh University, Gharuan, Punjab, 140413, India
| | - Akshay D Raul
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India
| | - Pravin Wanjari
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India.
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Quantum chemical study in exploring the role of donor→acceptor interactions in 1,3-bis carbene-stabilized guanidinium cations. J Mol Model 2021; 27:87. [PMID: 33598784 DOI: 10.1007/s00894-021-04707-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/08/2021] [Indexed: 10/22/2022]
Abstract
Guanidinium species are highly basic and hence mostly exist in cationic state. Because these cations carry electron-deficient centers, they can be stabilized with the help of electron-donating ligands like N-heterocyclic carbenes. A few novel guanidinium cationic species stabilized by electron-donating ligands were designed and quantum chemically evaluated. It was shown that strong hydrogen bonds and tautomerism are the important characteristics of these species. Further, the possibility of donor→acceptor coordination interactions in these species have been explored between the electron-donating carbenes and the central guanidinium unit. The results suggest that the title compounds can be considered as ligand-stabilized guanidinium cations similar to the ligand-stabilized N+ and N3+ centers.
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17
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Deng G, Pan S, Jin J, Wang G, Zhao L, Zhou M, Frenking G. Generation and Identification of the Linear OCBNO and OBNCO Molecules with 24 Valence Electrons. Chemistry 2021; 27:412-418. [PMID: 33104262 PMCID: PMC7839540 DOI: 10.1002/chem.202003886] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Indexed: 11/23/2022]
Abstract
Two structural isomers containing five second-row element atoms with 24 valence electrons were generated and identified by matrix-isolation IR spectroscopy and quantum chemical calculations. The OCBNO complex, which is produced by the reaction of boron atoms with mixtures of carbon monoxide and nitric oxide in solid neon, rearranges to the more stable OBNCO isomer on UV excitation. Bonding analysis indicates that the OCBNO complex is best described by the bonding interactions between a triplet-state boron cation with an electron configuration of (2s)0 (2pσ )0 (2pπ )2 and the CO/NO- ligands in the triplet state forming two degenerate electron-sharing π bonds and two ligand-to-boron dative σ bonds.
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Affiliation(s)
- Guohai Deng
- Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryShanghai Key Laboratory of, Molecular Catalysts and Innovative MaterialsFudan UniversityShanghai200438P.R. China
| | - Sudip Pan
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech UniversityNanjing211816P.R. China
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435043MarburgGermany
| | - Jiaye Jin
- Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryShanghai Key Laboratory of, Molecular Catalysts and Innovative MaterialsFudan UniversityShanghai200438P.R. China
| | - Guanjun Wang
- Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryShanghai Key Laboratory of, Molecular Catalysts and Innovative MaterialsFudan UniversityShanghai200438P.R. China
| | - Lili Zhao
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech UniversityNanjing211816P.R. China
| | - Mingfei Zhou
- Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryShanghai Key Laboratory of, Molecular Catalysts and Innovative MaterialsFudan UniversityShanghai200438P.R. China
| | - Gernot Frenking
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech UniversityNanjing211816P.R. China
- Fachbereich ChemiePhilipps-Universität MarburgHans-Meerwein-Strasse 435043MarburgGermany
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Yao S, Szilvási T, Xiong Y, Lorent C, Ruzicka A, Driess M. Bis(silylene)-Stabilized Monovalent Nitrogen Complexes. Angew Chem Int Ed Engl 2020; 59:22043-22047. [PMID: 32841449 PMCID: PMC7756627 DOI: 10.1002/anie.202011598] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Indexed: 01/08/2023]
Abstract
The first series of bis(silylene)-stabilized nitrogen(I) compounds is described. Starting from the 1,2-bis(N-heterocyclic silylenyl) 1,2-dicarba-closo-dedocaborane(12) scaffold 1, [1,2-(LSi)2 C2 B10 H10 ; L=PhC(Nt Bu)2 ], reaction with adamantyl azide (AdN3 ) affords the terminal N-μ2 -bridged zwitterionic carborane-1,2-bis(silylium) AdN3 adduct 2 with an open-cage dianionic nido-C2 B10 cluster core. Remarkably, upon one-electron reduction of 2 with C8 K and liberation of N2 and adamantane, the two silylene subunits are regenerated to furnish the isolable bis(silylene)-stabilized NI complex as an anion of 3 with the nido-C2 B10 cluster cage. On the other hand, one-electron oxidation of 2 with silver(I) yields the monocationic bis(silylene) NI complex 4 with the closo-C2 B10 cluster core. Moreover, the corresponding neutral NI radical complex 5 results from single-electron transfer from 3 to 4.
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Affiliation(s)
- Shenglai Yao
- Department of Chemistry: Metalorganics and Inorganic MaterialsTechnische Universität BerlinStrasse des 17. Juni 135, Sekr. C210623BerlinGermany
| | - Tibor Szilvási
- Department of Chemical & Biological EngineeringUniversity of Wisconsin-Madison1415 Engineering DriveMadisonWI53706USA
| | - Yun Xiong
- Department of Chemistry: Metalorganics and Inorganic MaterialsTechnische Universität BerlinStrasse des 17. Juni 135, Sekr. C210623BerlinGermany
| | - Christian Lorent
- Department of Chemistry, Physical and Biophysical ChemistryTechnische Universität BerlinStrasse des 17. Juni 135, Sekr. PC1410623BerlinGermany
| | - Ales Ruzicka
- Department of General and Inorganic ChemistryFaculty of Chemical TechnologyUniversity of PardubiceStudentska 573532 10PardubiceCzech Republic
| | - Matthias Driess
- Department of Chemistry: Metalorganics and Inorganic MaterialsTechnische Universität BerlinStrasse des 17. Juni 135, Sekr. C210623BerlinGermany
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Yao S, Szilvási T, Xiong Y, Lorent C, Ruzicka A, Driess M. Bis(silylene)‐Stabilized Monovalent Nitrogen Complexes. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011598] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Shenglai Yao
- Department of Chemistry: Metalorganics and Inorganic Materials Technische Universität Berlin Strasse des 17. Juni 135, Sekr. C2 10623 Berlin Germany
| | - Tibor Szilvási
- Department of Chemical & Biological Engineering University of Wisconsin-Madison 1415 Engineering Drive Madison WI 53706 USA
| | - Yun Xiong
- Department of Chemistry: Metalorganics and Inorganic Materials Technische Universität Berlin Strasse des 17. Juni 135, Sekr. C2 10623 Berlin Germany
| | - Christian Lorent
- Department of Chemistry, Physical and Biophysical Chemistry Technische Universität Berlin Strasse des 17. Juni 135, Sekr. PC14 10623 Berlin Germany
| | - Ales Ruzicka
- Department of General and Inorganic Chemistry Faculty of Chemical Technology University of Pardubice Studentska 573 532 10 Pardubice Czech Republic
| | - Matthias Driess
- Department of Chemistry: Metalorganics and Inorganic Materials Technische Universität Berlin Strasse des 17. Juni 135, Sekr. C2 10623 Berlin Germany
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20
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Patel N, Arfeen M, Singh T, Bhagat S, Sakhare A, Bharatam PV. Divalent N I Compounds: Identifying new Carbocyclic Carbenes to Design Nitreones using Quantum Chemical Methods. J Comput Chem 2020; 41:2624-2633. [PMID: 32964506 DOI: 10.1002/jcc.26417] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 11/05/2022]
Abstract
Nitreones are compounds with oxidation state 1 at the nitrogen, these compounds carry formal positive charge as well as two lone pairs of electrons at nitrogen center. These compounds are also known as divalent NI compounds and can be represented with the general formula L → N+ ← L, where L is an electron donating ligand. In the recent past, several divalent NI compounds have been reported with L = N-heterocyclic carbene (NHC), remote N-heterocyclic carbene (rNHC), carbocyclic carbene (CCC) and diaminocarbene. Recently, our group reported that a novel six-membered CCC (cyclohexa-2,5-diene-4-[diaminomethynyl]-1-ylidene) can stabilize N+ center in nitreones. As an independent carbene, this species is very unstable. In this work, modulation of this CCC using (a) annulation, (b) heterocyclic ring modification, (c) substitutions adjacent to the carbenic carbon, (d) exocyclic double bond insertion and (e) ring contraction, has been reported. These modulations and quantum chemical analyses helped in the identification of five new six-membered CCCs which carry improved donation and stability properties. Further, these CCCs were employed in the design of new divalent NI compounds (nitreones) which carry coordination bonds between ligands and N+ center. The molecular and electronic structure properties, and the donor→acceptor coordination interactions present in the resultant low oxidation state divalent NI compounds have been explored.
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Affiliation(s)
- Neha Patel
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab, India
- Biocon Bristol-Myers Squibb R&D Center (BBRC), Syngene International Ltd., Bengaluru, Karnataka, India
| | - Minhajul Arfeen
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab, India
| | - Tejender Singh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab, India
| | - Shweta Bhagat
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab, India
| | - Ajay Sakhare
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab, India
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Tahir MN, Ashfaq M, de la Torre AF, Caballero J, Hernández-Rodríguez EW, Ali A. Rationalizing the stability and interactions of 2,4-diamino-5-(4-chlorophenyl)-6-ethylpyrimidin-1-ium 2-hydroxy-3,5-dinitrobenzoate salt. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.05.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Bhagat S, Arfeen M, Das G, Ramkumar M, Khan SI, Tekwani BL, Bharatam PV. Design, synthesis and biological evaluation of 4-aminoquinoline-guanylthiourea derivatives as antimalarial agents. Bioorg Chem 2019; 91:103094. [PMID: 31376783 DOI: 10.1016/j.bioorg.2019.103094] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/10/2019] [Accepted: 06/26/2019] [Indexed: 11/15/2022]
Abstract
Guanylthiourea (GTU) has been identified as an important antifolate antimalarial pharmacophore unit, whereas, 4-amino quinolones are already known for antimalarial activity. In the present work molecules carrying 4-aminoquinoline and GTU moiety have been designed using molecular docking analysis with PfDHFR enzyme and heme unit. The docking results indicated that the necessary interactions (Asp54 and Ile14) and docking score (-9.63 to -7.36 kcal/mmol) were comparable to WR99210 (-9.89 kcal/mol). From these results nine molecules were selected for synthesis. In vitro analysis of these synthesized compounds reveal that out of the nine molecules, eight show antimalarial activity in the range of 0.61-7.55 μM for PfD6 strain and 0.43-8.04 μM for PfW2 strain. Further, molecular dynamics simulations were performed on the most active molecule to establish comparative binding interactions of these compounds and reference ligand with Plasmodium falciparum dihydrofolate reductase (PfDHFR).
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Affiliation(s)
- Shweta Bhagat
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar 160062, Punjab, India
| | - Minhajul Arfeen
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar 160062, Punjab, India
| | - Gourav Das
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar 160062, Punjab, India
| | - Mridula Ramkumar
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar 160062, Punjab, India
| | - Shabana I Khan
- National Center for Natural Products Research, University of Mississippi, MS 38677, USA
| | - Babu L Tekwani
- National Center for Natural Products Research, University of Mississippi, MS 38677, USA
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar 160062, Punjab, India.
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Singh T, Bharatam PV. Donor→acceptor coordination interactions in 1,3-bis(NHC)triazenyl Cations: An electronic structure analysis. J Comput Chem 2019; 40:2207-2215. [PMID: 31144352 DOI: 10.1002/jcc.25872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/16/2019] [Accepted: 05/16/2019] [Indexed: 11/08/2022]
Abstract
Donor→acceptor coordination interactions (L → N) between ligands and nitrogen center as in L → N⊕ ← L were reported in the recent past. This article describes the possibility of L → N coordination interactions in triazenyl cation species L → N3 ⊕ ← L. A few 1,3-bis(NHC)triazenyl cation species were experimentally known, the electronic structure analysis reported in this work reveals the presence of L → N (donor→acceptor) interactions in these species. Molecular orbital analysis, NBO charge analysis, energy decomposition analysis, and so forth, confirm the possibility of L → N coordination bond character. Ten molecules with the general formula L → N3 ⊕ ← L have been designed carrying L → N3 ⊕ ← L interactions. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Tejender Singh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar, Punjab, 160 062, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar, Punjab, 160 062, India
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24
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Singh T, George A, Parameswaran P, Bharatam PV. Enols, Diamino Enols, and Breslow Intermediates: A Comparative Quantum Chemical Analysis. European J Org Chem 2019. [DOI: 10.1002/ejoc.201801817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tejender Singh
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER), Sector 67; 160 062 S.A.S. Nagar - Punjab India
| | - Anjana George
- Department of Chemistry; National Institute of Technology Calicut; NIT Calicut Campus P.O. 673 601 Kozhikode - Kerala India
| | - Pattiyil Parameswaran
- Department of Chemistry; National Institute of Technology Calicut; NIT Calicut Campus P.O. 673 601 Kozhikode - Kerala India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER), Sector 67; 160 062 S.A.S. Nagar - Punjab India
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Affiliation(s)
- Mirosław Jabłoński
- Department of Quantum Chemistry, Faculty of ChemistryNicolaus Copernicus University in Toruń 7‐Gagarina St. Toruń 87‐100 Poland
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Chourasiya SS, Kathuria D, Wani AA, Bharatam PV. Azines: synthesis, structure, electronic structure and their applications. Org Biomol Chem 2019; 17:8486-8521. [DOI: 10.1039/c9ob01272a] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Azines (2,3-diaza-1,3-butadienes): structure, electronic structure, tautomerism, and their applications in organic synthesis, medicinal chemistry and materials chemistry.
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Affiliation(s)
- Sumit S. Chourasiya
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research (NIPER)
- India
| | - Deepika Kathuria
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research (NIPER)
- India
| | - Aabid Abdullah Wani
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research (NIPER)
- India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research (NIPER)
- India
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Bhagat S, Arfeen M, Das G, Patel N, Bharatam PV. Electronic and ligating properties of carbocyclic carbenes: A theoretical investigation. J Comput Chem 2018; 40:726-733. [PMID: 30549074 DOI: 10.1002/jcc.25756] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 10/27/2018] [Accepted: 11/01/2018] [Indexed: 11/05/2022]
Abstract
Carbocyclic carbenes (CCCs) are a class of nucleophilic carbenes which are very similar to N-heterocyclic carbenes (NHCs) in terms of their reactivity, but they do not contain a stabilizing heteroatom in their cyclic ring system. In this study, 17 representative known CCCs and 34 newly designed CCCs are evaluated using quantum chemical methods, and the results are compared in terms of their stability, nucleophilicity, and proton affinity (PA) parameters. The results are divided on the basis of ring size of the known and reported CCCs. The stability, nucleophilicity, PA, complexation energy, and bond strength-related parameters were estimated using M06/6-311++G(d,p) method. The results indicated that the CCCs known in the literature are strong σ-electron donating species and have considerable π-accepting properties. This study led to the design and identification of a few new CCCs with dimethylamine and diaminomethynyl substituents which can be singlet stable and are substantially nucleophilic. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Shweta Bhagat
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Mohali, Punjab, 160062, India
| | - Minhajul Arfeen
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Mohali, Punjab, 160062, India
| | - Gourav Das
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Mohali, Punjab, 160062, India
| | - Neha Patel
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Mohali, Punjab, 160062, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Mohali, Punjab, 160062, India
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Ramesh M, Bharatam PV. Formation of a Toxic Quinoneimine Metabolite from Diclofenac: A Quantum Chemical Study. Drug Metab Lett 2018; 13:64-76. [PMID: 30210009 DOI: 10.2174/1872312812666180913120736] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 08/27/2018] [Accepted: 08/27/2018] [Indexed: 01/26/2023]
Abstract
BACKGROUND Diclofenac is a non-steroidal antiinflammatory drug. It is predominantly metabolized by CYP2C9. 4'-hydroxydiclofenac and its quinoneimine are the metabolites of diclofenac. However, few numbers of serious cases of idiosyncratic hepatotoxicity due to diclofenac metabolism were reported. The formation of the quinoneimine metabolite was found to be responsible for this idiosyncratic toxicity. Quinoneimine is an over-oxidized metabolite of diclofenac. METHOD In this work, computational studies were conducted to detail the formation of a quinoneimine metabolite from diclofenac. Further, the idiosyncratic toxicity of quinoneimine due to its reactivity was also investigated by quantum chemical analysis. RESULTS & CONCLUSION The results demonstrate the possibility of formation of quinoneimine metabolite due to various factors that are involved in the metabolism of diclofenac. The present study may provide the structural in-sights during the drug development processes to avoid the metabolism directed idiosyncratic toxicity.
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Affiliation(s)
- Muthusamy Ramesh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar (Mohali)-160 062, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar (Mohali)-160 062, India
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Abstract
Phase-transfer catalysts (PTCs), currently, are one of the most important tools of chemists for performing organic reactions. PTCs accelerate several types of reactions in biphasic systems, giving excellent yields of the desired product. Most of the PTCs belong to the general formula NR4+X-. In the recent past, several compounds possessing a novel scaffold with the general formula NL2+X- have been reported as PTCs. In the NL2+ species, a nitrogen atom with a formal positive charge accepts electron density from electron-donating ligands. Electronic structure studies reported in the literature confirmed the possibility of L → N coordination (donor-acceptor) interactions in these species, and thus, this class of compounds are known as divalent NI compounds. These species are reported to exhibit better catalytic potential in comparison to the traditional NR4+ systems. Some of the NL2+ systems are found to be useful in asymmetric phase-transfer catalysis. Thus, these systems offer extensive opportunities for exploring the catalytic properties and novel mechanistic aspects associated with their unique electronic structure. In this paper, the synthesis, electronic, and structural properties and the applications in catalysis of the NL2+-based PTCs are reviewed with their bright future scope in catalytic organic chemistry.
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Affiliation(s)
- Neha Patel
- Department of Medicinal Chemistry , National Institute of Pharmaceutical Education and Research (NIPER) , Sector 67, Sahibzada Ajit Singh Nagar 160 062 , Punjab , India
| | - Radhika Sood
- Department of Medicinal Chemistry , National Institute of Pharmaceutical Education and Research (NIPER) , Sector 67, Sahibzada Ajit Singh Nagar 160 062 , Punjab , India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry , National Institute of Pharmaceutical Education and Research (NIPER) , Sector 67, Sahibzada Ajit Singh Nagar 160 062 , Punjab , India
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Patel N, Arfeen M, Sood R, Khullar S, Chakraborti AK, Mandal SK, Bharatam PV. Can Remote N-Heterocyclic Carbenes Coordinate with Main Group Elements? Synthesis, Structure, and Quantum Chemical Analysis of N + -Centered Complexes. Chemistry 2018; 24:6418-6425. [PMID: 29504658 DOI: 10.1002/chem.201705999] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Indexed: 11/11/2022]
Abstract
Remote N-heterocyclic carbenes (rNHCs), such as N-methyl-4-pyridylidene, are known to form coordination complexes with TMs. Herein, it is established that rNHCs can also coordinate to the N+ centre. Synthesis of some novel divalent NI complexes with the general formula (rNHC)→N+ ←(NHC) and (rNHC)→N+ ←(rNHC) was achieved, and X-ray diffraction studies supported the coordination bond character between the rNHCs and the N+ centre. Quantum chemical analysis established the presence of divalent NI character at the central nitrogen in these systems.
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Affiliation(s)
- Neha Patel
- National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S., Nagar, 160 062, Punjab, India
| | - Minhajul Arfeen
- National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S., Nagar, 160 062, Punjab, India
| | - Radhika Sood
- National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S., Nagar, 160 062, Punjab, India
| | - Sadhika Khullar
- Department of Chemistry, D.A.V. University, Jalandhar-Pathankot National Highway, Jalandhar, 144012, Punjab, India
| | - Asit K Chakraborti
- National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S., Nagar, 160 062, Punjab, India
| | - Sanjay K Mandal
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Sector 81, S.A.S., Nagar, 140 308, Punjab, India
| | - Prasad V Bharatam
- National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S., Nagar, 160 062, Punjab, India
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Yang T, Andrada DM, Frenking G. Dative versus electron-sharing bonding in N-oxides and phosphane oxides R3EO and relative energies of the R2EOR isomers (E = N, P; R = H, F, Cl, Me, Ph). A theoretical study. Phys Chem Chem Phys 2018; 20:11856-11866. [DOI: 10.1039/c8cp00951a] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Quantum chemical calculations using ab initio methods at the CCSD(T)/def2-TZVPP level and density functional theory using BP86 and M06-2X functionals in conjunction with def2-TZVPP basis sets have been carried out on the title molecules.
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Affiliation(s)
- Tao Yang
- Fachbereich Chemie
- Philipps-Universität Marburg
- Marburg 35032
- Germany
| | - Diego M. Andrada
- Fachbereich Chemie
- Philipps-Universität Marburg
- Marburg 35032
- Germany
| | - Gernot Frenking
- Fachbereich Chemie
- Philipps-Universität Marburg
- Marburg 35032
- Germany
- Institute of Advanced Synthesis
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34
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Andersen V, Berg RW, Shim I. Ab Initio Assessment of the Bonding in Disulfonates Containing Divalent Nitrogen and Phosphorus Atoms. ACS OMEGA 2017; 2:4447-4455. [PMID: 31457737 PMCID: PMC6641889 DOI: 10.1021/acsomega.7b00266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/19/2017] [Indexed: 06/10/2023]
Abstract
The iminodisulfonate, [N(SO3)2]3-, and phosphinodisulfonate, [P(SO3)2]3-, ions have been investigated by performing ab initio MP2/6-311+G** calculations. The nitrogen and phosphorus atoms as part of the ions are shown to be divalent with a negative charge and two lone pairs on the nitrogen and phosphorus atoms. The experimentally known calcium sodium iminodisulfonate trihydrate and the analogous unknown compound calcium sodium phosphinodisulfonate trihydrate have also been investigated using the MP2/6-311+G** calculations. For the nitrogen compound, only minor changes occur in the iminodisulfonate ion when it becomes part of the calcium sodium iminodisulfonate trihydrate. For the phosphorus compound, the geometry of the phosphinodisulfonate ion changes significantly as part of calcium sodium phosphinodisulfonate trihydrate. Furthermore, the charges associated with the atoms in calcium sodium phosphinodisulfonate trihydrate are quite different from those of the phosphinodisulfonate ion. For calcium sodium iminodisulfonate trihydrate, the Raman spectrum has been measured, and it compares well with the spectrum derived using HF/6-311+G** calculations.
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Affiliation(s)
| | | | - Irene Shim
- E-mail: . Phone: +45 4525 5432. Fax: +45 4588 3136 (I.S.)
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35
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36
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Guanylthiourea derivatives as potential antimalarial agents: Synthesis, in vivo and molecular modelling studies. Eur J Med Chem 2017; 135:339-348. [DOI: 10.1016/j.ejmech.2017.04.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 04/03/2017] [Accepted: 04/10/2017] [Indexed: 11/21/2022]
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37
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Chourasiya SS, Patel DR, Nagaraja CM, Chakraborti AK, Bharatam PV. Sulfonamide vs. sulfonimide: tautomerism and electronic structure analysis of N-heterocyclic arenesulfonamides. NEW J CHEM 2017. [DOI: 10.1039/c7nj01353a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Experimental and computational studies suggest a preference toward the sulfonimide tautomer in N-heterocyclic arenesulfonamide.
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Affiliation(s)
- Sumit S. Chourasiya
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research
- Punjab – 160 062
- India
| | - Dhara R. Patel
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research
- Punjab – 160 062
- India
| | - C. M. Nagaraja
- Department of Chemistry
- Indian Institute of Technology (IIT) Ropar
- Roopnagar – 140 001
- India
| | - Asit K. Chakraborti
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research
- Punjab – 160 062
- India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research
- Punjab – 160 062
- India
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38
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Morosaki T, Fujii T. Recent Advances in Heteroatom-Stabilized Carbones and Their Metal Complexes. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2017. [DOI: 10.1016/bs.adomc.2017.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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39
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Bharatam PV, Arfeen M, Patel N, Jain P, Bhatia S, Chakraborti AK, Khullar S, Gupta V, Mandal SK. Design, Synthesis, and Structural Analysis of Divalent N(I) Compounds and Identification of a New Electron-Donating Ligand. Chemistry 2015; 22:1088-96. [PMID: 26615987 DOI: 10.1002/chem.201503618] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Indexed: 11/09/2022]
Abstract
The dative-bond representation (L→E) in compounds with main group elements (E) has triggered extensive debate in the recent past. The scope and limits of this nonclassical coordination bond warrant comprehensive exploration. Particularly compounds with (L→N←L')(+) arrangement are of special interest because of their therapeutic importance. This work reports the design and synthesis of novel chemical species with the general structural formula (L→N←L')(+) carrying the unusual ligand cyclohexa-2,5-diene-4-(diaminomethynyl)-1-ylidene. Four species belonging to the (L→N←L')(+) class carrying this unconventional ligand were synthesized. Quantum chemical and X-ray diffraction analyses showed that the electronic and geometric parameters are consistent with those of already reported divalent N(I) compounds. The molecular orbital analysis, geometric parameters, and spectral data clearly support the L→N and N←L' interactions in these species. The newly identified ligand has the properties of a reactive carbene and high nucleophilicity.
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Affiliation(s)
- Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar -, 160 062, Punjab, India.
| | - Minhajul Arfeen
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar -, 160 062, Punjab, India
| | - Neha Patel
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar -, 160 062, Punjab, India
| | - Priyanka Jain
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar -, 160 062, Punjab, India
| | - Sonam Bhatia
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar -, 160 062, Punjab, India
| | - Asit K Chakraborti
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar -, 160 062, Punjab, India.
| | - Sadhika Khullar
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Sector 81, S.A.S. Nagar -, 140 308, Punjab, India
| | - Vijay Gupta
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Sector 81, S.A.S. Nagar -, 140 308, Punjab, India
| | - Sanjay K Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Sector 81, S.A.S. Nagar -, 140 308, Punjab, India.
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40
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Ramakrishnan A, Chourasiya SS, Bharatam PV. Azine or hydrazone? The dilemma in amidinohydrazones. RSC Adv 2015. [DOI: 10.1039/c5ra05574a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Amidinohydrazone, an important class of biologically active molecules, is generally represented as a hydrazone. This moiety prefers to exist in its azine tautomeric state and hence, influences the physical, chemical and receptor binding properties.
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Affiliation(s)
- Ashok Ramakrishnan
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research
- Mohali
- India
| | - Sumit S. Chourasiya
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research
- Mohali
- India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry
- National Institute of Pharmaceutical Education and Research
- Mohali
- India
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41
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Singh S, Wanjari PJ, Bhatia S, Sonwane VC, Chakraborti AK, Bharatam PV. Design, synthesis, biological evaluation and toxicity studies of N,N-disubstituted biguanides as quorum sensing inhibitors. Med Chem Res 2014. [DOI: 10.1007/s00044-014-1255-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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42
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Arfeen M, Patel DS, Abbat S, Taxak N, Bharatam PV. Importance of cytochromes in cyclization reactions: Quantum chemical study on a model reaction of proguanil to cycloguanil. J Comput Chem 2014; 35:2047-55. [DOI: 10.1002/jcc.23719] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 08/04/2014] [Accepted: 08/06/2014] [Indexed: 12/23/2022]
Affiliation(s)
- Minhajul Arfeen
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Dhilon S. Patel
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Sheenu Abbat
- Department of Pharmacoinformatics; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Nikhil Taxak
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
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43
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Mirabdolbaghi R, Dudding T, Stamatatos T. A Class of Phase-Transfer Catalyst with Interionic Strain: Insight into the Bonding of Disubstituted N- vs Carbene-Stabilized NI-Centered Cations. Org Lett 2014; 16:2790-3. [DOI: 10.1021/ol501068f] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Roya Mirabdolbaghi
- Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2R1H1, Canada
| | - Travis Dudding
- Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2R1H1, Canada
| | - Theocharis Stamatatos
- Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2R1H1, Canada
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44
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Bhatia S, Bharatam PV. Possibility of the Existence of Donor–Acceptor Interactions in Bis(azole)amines: An Electronic Structure Analysis. J Org Chem 2014; 79:4852-62. [DOI: 10.1021/jo402862r] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Sonam Bhatia
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S.
Nagar, Punjab 160 062, India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S.
Nagar, Punjab 160 062, India
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45
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Design and synthesis of guanylthiourea derivatives as potential inhibitors of Plasmodium falciparum dihydrofolate reductase enzyme. Bioorg Med Chem Lett 2014; 24:613-7. [DOI: 10.1016/j.bmcl.2013.12.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/22/2013] [Accepted: 12/02/2013] [Indexed: 11/18/2022]
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46
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Nathavad ZP, Bhatia S, Dhaked DK, Bharatam PV. Electronic structure analysis of isomeric preferences of canonical and zwitterionic forms of lornoxicam. COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2013.09.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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47
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Broeckaert L, Frenking G, Geerlings P, De Proft F. Reactivity of Dicoordinated Stannylones (Sn
0
) versus Stannylenes (Sn
II
): An Investigation Using DFT‐Based Reactivity Indices. Chemphyschem 2013; 14:3233-47. [DOI: 10.1002/cphc.201300596] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Lies Broeckaert
- Department of General Chemistry (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels (Belgium)
| | - Gernot Frenking
- Fachbereich Chemie, Philipps‐Universität Marburg, Hans‐Meerwein‐Straße, 35032 Marburg (Germany)
| | - Paul Geerlings
- Department of General Chemistry (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels (Belgium)
| | - Frank De Proft
- Department of General Chemistry (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels (Belgium)
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48
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Celik MA, Frenking G, Neumüller B, Petz W. Exploiting the Twofold Donor Ability of Carbodiphosphoranes: Theoretical Studies of [(PPh3)2C→EH2]q(Eq=Be, B+, C2+, N3+, O4+) and Synthesis of the Dication [(Ph3P)2CCH2]2+. Chempluschem 2013; 78:1024-1032. [DOI: 10.1002/cplu.201300169] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Indexed: 11/06/2022]
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49
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Bhatia S, Malkhede YJ, Bharatam PV. Existence of dynamic tautomerism and divalent N(I) character in N-(pyridin-2-yl)thiazol-2-amine. J Comput Chem 2013; 34:1577-88. [PMID: 23609068 DOI: 10.1002/jcc.23293] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 03/14/2013] [Accepted: 03/15/2013] [Indexed: 01/23/2023]
Abstract
N-(pyridin-2-yl)thiazol-2-amine is a versatile chemical functional unit present in many therapeutically important species. Quantum chemical analysis shows that there are six competitive isomeric structures possible for this class of compounds within a relative energy difference of ∼4 kcal/mol. Some of the isomeric structures possess divalent N(I) character. There appears to be a competition between the thiazole and pyridine groups to accommodate the tautomeric hydrogen, and consequently show electron donating property in the structure with R-N←L representation. Details of electron distribution, tautomeric preferences, protonation energy, and divalent N(I) character, and so on, of this class of compounds are presented in this article. Subsequently, upon protonation, (L→N←L)(⊕) character is clearly evident in these moieties as molecular orbital analysis clearly shows two lone pairs of electrons on the central nitrogen, in this system.
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Affiliation(s)
- Sonam Bhatia
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S. A. S. Nagar, Mohali, Punjab, 160 062, India
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50
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Taxak N, Patel B, Bharatam PV. Carbene Generation by Cytochromes and Electronic Structure of Heme-Iron-Porphyrin-Carbene Complex: A Quantum Chemical Study. Inorg Chem 2013; 52:5097-109. [DOI: 10.1021/ic400010d] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Nikhil Taxak
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar (Mohali), 160 062 Punjab, India
| | - Bhargav Patel
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar (Mohali), 160 062 Punjab, India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar (Mohali), 160 062 Punjab, India
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