Theoretical study on the mechanism of a ring-opening reaction of oxirane by the active-site aspartic dyad of HIV-1 protease

2008 ◽  
Vol 6 (2) ◽  
pp. 359-365 ◽  
Author(s):  
Juraj Kóňa
Keyword(s):  
Active Site ◽  
Ring Opening ◽  
Theoretical Study ◽  
Ring Opening Reaction ◽  
Hiv 1

Ring Opening of 1,1’-sulfonyl bis-aziridines Derived from L-Amino Acids and DFT Study on their Affinity Toward Different Nucleophiles

2021 ◽  
Vol 18 ◽  
Author(s):  
Nawel Khettache ◽  
Mohamed Dehamchia ◽  
Sihem Hessainia ◽  
Tahar Abbaz ◽  
Zine Régaïnia
Keyword(s):  
Ring Opening ◽  
Density Functional ◽  
Theoretical Study ◽  
Sodium Ethoxide ◽  
Aziridine Ring ◽  
Functional Theory ◽  
Cyanide Anion ◽  
Anionic Nucleophiles ◽  
Ring Opening Reaction ◽  
Selective Ring Opening

: We describe herein the ring-opening reaction of chiral 1,1’-sulfonyl bis-aziridines with various neutral and anionic nucleophiles, including benzylamine, piperidine, acetate, allyl thiolate, cyanide anion, and sodium ethoxide. These reactions afforded bis-opened or/and mono-opened compounds via a regioselective attack on the non-substituted methylene of aziridine ring. The structures of the products were confirmed based on spectral analysis (IR, 1H NMR, and 13C NMR). A theoretical study involving density functional theory (DFT) was used to rationalize the region-selective ring-opening of starting bis-aziridines.

scholarly journals Theoretical study on the nucleophilic fluoroalkylation of propylene oxide with fluorinated sulfones

2013 ◽  
Vol 78 (4) ◽  
pp. 483-494
Author(s):  
Ling-Li Han ◽  
Tao Liu
Keyword(s):  
Gas Phase ◽  
Propylene Oxide ◽  
Nucleophilic Addition ◽  
Ring Opening ◽  
Theoretical Study ◽  
Addition Reactions ◽  
Ring Opening Reaction ◽  
Reactivity Order ◽  
Better Than ◽  
Good Agreement

The path of nucleophilic fluoroalkylation reaction of propylene oxide with PhSO2CYF- (Y=F,H, and PhSO2, respectively) in gas phase and in Et2O solvent were studied theoretically. The nucleophilic fluoroalkylation of propylene oxide with fluorinated carbanions was probed by the reactivity comparison between (benzenesulfonyl)monofluoromethyl anion (PhSO2CHF-), (benzenesulfonyl) difluoromethyl anion (PhSO2CF2-), and bis(benzenesul-fonyl) monofluoromethyl anion ((PhSO2)2CF-). The nucleophilicity reactivity order of PhSO2CYF- (Y = F, H, and PhSO2) is [(PhSO2)2CF-] > PhSO2CHF- > PhSO2CF2-, which indicates that introducing another electron-withdrawing benzenesulfonyl group is an effective way to significantly increase the nucleophilicity of the fluorinate carbanions. For comparison, we also studied the nucleophilic addition reactions of propylene oxide with chlorine substituted carbanion PhSO2CHCl-. The calculated results show that the nucleophilicity of PhSO2CYF- is better than that of PhSO2CHCl- for the ring opening reaction with propylene oxide. The calculated results are in good agreement with the available experiments.

On the Conrotatory Ring Opening of 3-Carbomethoxycyclobutene Vis-À-Vis 3-Carbomethoxy-1,2-Benzocyclobutene and the Predominant Inward Opening of 3-Dimethylaminocarbonyl-1,2-Benzocyclobutene

2018 ◽  
Author(s):  
Veejendra Yadav ◽  
Dasari L V K Prasad ◽  
Arpita Yadav ◽  
Maddali L N Rao
Keyword(s):  
Transition State ◽  
Ring Opening ◽  
Electron Process ◽  
Ring Opening Reaction ◽  
Stable Species ◽  
Electron Event

<p>The torquoselectivity of conrotatory ring opening of 3-carbomethoxycyclobutene is controlled by p<sub>C1C2</sub>→s*<sub>C3C4</sub> and s<sub>C3C4</sub>→p*<sub>CO</sub> interactions in the transition state in a 4-electron process as opposed to only s<sub>C3C4</sub>→p*<sub>CO</sub> interaction in an apparently 8-electron event in 3-carbomethoxy-1,2-benzocyclobutene. The ring opening of 3-carbomethoxy-1,2-benzocyclobutene is sufficiently endothermic. We therefore argue that the reverse ring closing reaction is faster than the forward ring opening reaction and, thus, it establishes an equilibrium between the two and subsequently allows formation of the more stable species <i>via</i> outward ring opening reaction. Application of this argument to 3-dimethylaminocarbonyl-1,2-benzocyclobutene explains the predominantly observed inward opening.</p>

scholarly journals Expanding Monomers as Anti-Shrinkage Additives

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 806
Author(s):  
Philipp Marx ◽  
Frank Wiesbrock
Keyword(s):  
Ring Opening ◽  
Covalent Bond ◽  
Volumetric Shrinkage ◽  
Structure Property ◽  
Atomic Packing ◽  
Materials Properties ◽  
Volumetric Expansion ◽  
Structure Property Relationships ◽  
Ring Opening Reaction ◽  
Measuring Techniques

Commonly, volumetric shrinkage occurs during polymerizations due to the shortening of the equilibrium Van der Waals distance of two molecules to the length of a (significantly shorter) covalent bond. This volumetric shrinkage can have severe influence on the materials’ properties. One strategy to overcome this volumetric shrinkage is the use of expanding monomers that show volumetric expansion during polymerization reactions. Such monomers exhibit cyclic or even oligocyclic structural motifs with a correspondingly dense atomic packing. During the ring-opening reaction of such monomers, linear structures with atomic packing of lower density are formed, which results in volumetric expansion or at least reduced volumetric shrinkage. This review provides a concise overview of expanding monomers with a focus on the elucidation of structure-property relationships. Preceded by a brief introduction of measuring techniques for the quantification of volumetric changes, the most prominent classes of expanding monomers will be presented and discussed, namely cycloalkanes and cycloalkenes, oxacycles, benzoxazines, as well as thiocyclic compounds. Spiroorthoesters, spiroorthocarbonates, cyclic carbonates, and benzoxazines are particularly highlighted.

Design and synthesis of 1,8-Naphthalimide Functionalized Benzothiadiazoles

2021 ◽  
Author(s):  
Rajneesh Misra ◽  
Yogjivan Rout
Keyword(s):  
Ring Opening ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Design And Synthesis ◽  
Cross Coupling Reaction ◽  
Ring Opening Reaction

A series of multi acceptor based push-pull derivatives BTD2–BTD5 were designed and synthesized via Pd-catalyzed Sonogashira cross-coupling reaction followed by [2+2] cycloaddition–electrocyclic ring-opening reaction in which benzothiadiazole (BTD, A1), naphthalimide...

Theoretical study of photoinduced ring-opening in furan

2010 ◽  
Vol 133 (16) ◽  
pp. 164309 ◽  
Author(s):  
E. V. Gromov ◽  
A. B. Trofimov ◽  
F. Gatti ◽  
H. Köppel
Keyword(s):  
Ring Opening ◽  
Theoretical Study

scholarly journals (1R,4S,5S)-5-((3-Hydroxypropyl)amino)-4-((1-Methyl-1H-tetrazol-5-yl)thio)Cyclopent-2-en-1-ol

Molbank ◽  
10.3390/m1199 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1199
Author(s):  
Milene A. G. Fortunato ◽  
Filipa Siopa ◽  
Carlos A. M. Afonso
Keyword(s):  
Spectral Data ◽  
13C Nmr ◽  
Ring Opening ◽  
Environmentally Friendly ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Excellent Yield ◽  
Ring Opening Reaction ◽  
Nucleophilic Ring Opening

Using environmentally friendly conditions, the nucleophilic ring-opening reaction of 6-azabicyclo[3.1.0]hex-3-en-2-ol with 1-methyl-1H-tetrazole-5-thiol provided a novel thiol-incorporated aminocyclopentitol, (1R,4S,5S)-5-((3-hydroxypropyl)amino)-4-((1-methyl-1H-tetrazol-5-yl)thio)cyclopent-2-en-1-ol, in excellent yield (95%). The newly synthesized compound was analyzed and characterized via 1H, 13C-NMR, HSQC, and mass spectral data.

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