The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Yuchang Chang - One of the best experts on this subject based on the ideXlab platform.
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density functional studies on dicobalt octacarbonyl mediated urea formation from primary amine
Organometallics, 2004Co-Authors: Funge Hong, Yuchang ChangAbstract:Two adiabatic potential energy surfaces (PES) are employed for probing the process of the formation of the urea-like compound CH 3 HNC(=O)NHCH 3 , which is mediated by dicobalt octacarbonyl from the primary amine NH 2 CH 3 , by utilizing the density functional theory method at the B3LYP/631LAN level. These two reaction pathways described here are route 1, which is designated as an insertion-addition pathway, and route 2, an addition-insertion pathway. Elementary steps for both reaction pathways, including the amino group migration to the Co-CO bond, additional NH 2 CH 3 molecule association, oxidative addition of the coordinated amine proton to the cobalt center, and reductive elimination of -C(=O)NHCH 3 with -NH 2 CH 3 , are modeled and examined. Rather small energies for activation (ΔG ) , 2.3 and 2.1 kcal/mol for routes 1 and 2, respectively, are observed for the process of amino group migration and the formation of the Co-carbamyl bond in both routes. The results are in contrast to the alkyl group migration in RCo(CO) 4 cases, in which much higher energies are required. The oxidative addition process of the N-H bond is established as the rate-determining step (rds) for both routes, and the activation energies ΔG are 49.2 and 56.8 kcal/mol for routes 1 and 2, respectively. All the elementary steps are thermodynamically favorable, except for the oxidative addition process of the N-H bond to the cobalt center. These large energy barriers are responsible for the rigorous reaction conditions required in common transition-metal-mediated urea formation reactions and the low to medium yield in our previously reported cobalt carbonyl mediated urea-like compound formation from propargylamine. On the whole, route 2 is an energetically less favorable and more complicated reaction pathway than route 1. Furthermore, another compound, a Formamide Derivative, is predicted as a potential product from a competitive reaction of route 1 by our theoretical study. The process has a ΔG value smaller than that of the formation of the urea product. Nevertheless, there has been no experimental evidence for the formation of Formamide until now.
Funge Hong - One of the best experts on this subject based on the ideXlab platform.
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density functional studies on dicobalt octacarbonyl mediated urea formation from primary amine
Organometallics, 2004Co-Authors: Funge Hong, Yuchang ChangAbstract:Two adiabatic potential energy surfaces (PES) are employed for probing the process of the formation of the urea-like compound CH 3 HNC(=O)NHCH 3 , which is mediated by dicobalt octacarbonyl from the primary amine NH 2 CH 3 , by utilizing the density functional theory method at the B3LYP/631LAN level. These two reaction pathways described here are route 1, which is designated as an insertion-addition pathway, and route 2, an addition-insertion pathway. Elementary steps for both reaction pathways, including the amino group migration to the Co-CO bond, additional NH 2 CH 3 molecule association, oxidative addition of the coordinated amine proton to the cobalt center, and reductive elimination of -C(=O)NHCH 3 with -NH 2 CH 3 , are modeled and examined. Rather small energies for activation (ΔG ) , 2.3 and 2.1 kcal/mol for routes 1 and 2, respectively, are observed for the process of amino group migration and the formation of the Co-carbamyl bond in both routes. The results are in contrast to the alkyl group migration in RCo(CO) 4 cases, in which much higher energies are required. The oxidative addition process of the N-H bond is established as the rate-determining step (rds) for both routes, and the activation energies ΔG are 49.2 and 56.8 kcal/mol for routes 1 and 2, respectively. All the elementary steps are thermodynamically favorable, except for the oxidative addition process of the N-H bond to the cobalt center. These large energy barriers are responsible for the rigorous reaction conditions required in common transition-metal-mediated urea formation reactions and the low to medium yield in our previously reported cobalt carbonyl mediated urea-like compound formation from propargylamine. On the whole, route 2 is an energetically less favorable and more complicated reaction pathway than route 1. Furthermore, another compound, a Formamide Derivative, is predicted as a potential product from a competitive reaction of route 1 by our theoretical study. The process has a ΔG value smaller than that of the formation of the urea product. Nevertheless, there has been no experimental evidence for the formation of Formamide until now.
Sahaj A Gandhi - One of the best experts on this subject based on the ideXlab platform.
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molecular docking study and hirshfeld surface analysis of Formamide Derivative
Social Science Research Network, 2020Co-Authors: Tanvirbanu J Malek, Urmila H Patel, Dhaval Shah, Sahaj A GandhiAbstract:Formamide (HCONH2), a formic acid amide, has its versatile properties as an intermediate in the agrochemical and pharmaceutical industries and for the production of vitamins and pyrimidines. N-(4-Bromo-Phenyl)-Formamide is a novel Derivative of Formamide with bromo-phenyl moiety substituted at nitrogen. The title molecule is a moderate antimicrobial agent. The synthesized compound, C7H6BrNO has been confirmed by single crystal X-ray diffraction studies. This molecule crystallizes in centric orthorhombic crystal system and space-group Pbca with crystal parameters a=10.8560(19) Ǻ, b=9.8166(17) Ǻ, c=13.912(40) Ǻ and Z=8. The number of weak but significant C–H…O, N–H…O and π–π interactions take part in the stability of crystal packing. Qualitative and quantitative contributions of intermolecular interactions in molecular structure are investigated by Hirshfeld surface analysis and 2D fingerprint plots. In order to study the structure-function relationship of the ligand with different receptors and to determine the lowest free energy structures for the receptor ligand complex, docking study has been carried out. The different receptors are docked with title compound and the energy value calculated.
Chang Y.c. - One of the best experts on this subject based on the ideXlab platform.
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Density functional studies on dicobalt octacarbonyl mediated urea formation from primary amine
2014Co-Authors: Hong F.e., Chang Y.c.Abstract:Two adiabatic potential energy surfaces (PES) are employed for probing the process of the formation of the urea-like compound CH3HNC(=O)NHCH3, which is mediated by dicobalt octacarbonyl from the primary amine NH2CH3, by utilizing the density functional theory method at the B3LYP/631LAN level. These two reaction pathways described here are route 1, which is designated as an insertion-addition pathway, and route 2, an addition-insertion pathway. Elementary steps for both reaction pathways, including the amino group migration to the Co-CO bond, additional NH2CH3 molecule association, oxidative addition of the coordinated amine proton to the cobalt center, and reductive elimination of -C(=O)NHCH3 with -NH2CH3, are modeled and examined. Rather small energies for activation (DeltaG(double dagger)), 2.3 and 2.1 kcal/mol for routes 1 and 2, respectively, are observed for the process of amino group migration and the formation of the Co-carbamyl bond in both routes. The results are in contrast to the alkyl group migration in RCo(CO)(4) cases, in which much higher energies are required. The oxidative addition process of the N-H bond is established as the rate-determining step (rds) for both routes, and the activation energies DeltaG(double dagger) are 49.2 and 56.8 kcal/mol for routes 1 and 2, respectively. All the elementary steps are thermodynamically favorable, except for the oxidative addition process of the N-H bond to the cobalt center. These large energy barriers are responsible for the rigorous reaction conditions required in common transition-metal-mediated urea formation reactions and the low to medium yield in our previously reported cobalt carbonyl mediated urea-like compound formation from propargylamine. On the whole, route 2 is an energetically less favorable and more complicated reaction pathway than route 1. Furthermore, another compound, a Formamide Derivative, is predicted as a potential product from a competitive reaction of route 1 by our theoretical study. The process has a DeltaG(double dagger) value smaller than that of the formation of the urea product. Nevertheless, there has been no experimental evidence for the formation of Formamide until now
Francois Tillequin - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of models of metabolites: Oxidation of variously substituted chromenes including acronycine, by a porphyrin catalytic system
Journal of Heterocyclic Chemistry, 2005Co-Authors: Bernardin Akagah, Elisabeth Seguin, François Estour, Philippe Vérité, Olivier Lafont, Francois TillequinAbstract:The influence of chemical neighbouring on oxidation of substituted 2,2‐dimethylchromenes Derivatives 5‐8 by a biomimetic catalytic system was first studied. It was then applied to acronycine an anti‐cancer drug in order to obtain in one single step oxidized products resulting from the reactivity of the 1,2‐double bond in the pyranic D‐ring. These 2,2‐dimethylchromenes constitute the structural moiety responsible for the activity of acronycine. This oxidation showed the sensitivity of the ethylenic bond, leading to the formation of the corresponding epoxides, diols and/or ketoalcohol. In the case of 5‐dimethylamino‐2,2‐dimethylchromene 8 , the double bond was not sensitive to oxidation, but the N ‐methyl groups reacted to lead to the Formamide Derivative 16 and an imino‐alcohol 17 . This methodology applied to acronycine molecule 1 , allowed to obtain in one step, two oxidized compounds, a trans ‐diol 3 and a ketoalcohol 4 under preparative conditions.