Theoretical study of the pathway for diazine ring formation in a series of 4-dimethylaminonaphthalic acid derivatives under Vilsmeier-Haack reaction conditions

2000 ◽  
Vol 36 (4) ◽  
pp. 183-186 ◽  
Author(s):  
L. D. Patsenker
Keyword(s):  
Theoretical Study ◽  
Ring Formation ◽  
Reaction Conditions

scholarly journals Prebiotic Route to Thymine from Formamide—A Combined Experimental–Theoretical Study

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2248
Author(s):  
Lukáš Petera ◽  
Klaudia Mrazikova ◽  
Lukas Nejdl ◽  
Kristyna Zemankova ◽  
Marketa Vaculovicova ◽  
...  
Keyword(s):  
Formic Acid ◽  
Quantum Chemical ◽  
Prebiotic Chemistry ◽  
Theoretical Study ◽  
Reaction Pathway ◽  
Hydrolysis Product ◽  
Current Paper ◽  
Reaction Conditions ◽  
Chemical Modeling ◽  
Chemistry Research

Synthesis of RNA nucleobases from formamide is one of the recurring topics of prebiotic chemistry research. Earlier reports suggest that thymine, the substitute for uracil in DNA, may also be synthesized from formamide in the presence of catalysts enabling conversion of formamide to formaldehyde. In the current paper, we show that to a lesser extent conversion of uracil to thymine may occur even in the absence of catalysts. This is enabled by the presence of formic acid in the reaction mixture that forms as the hydrolysis product of formamide. Under the reaction conditions of our study, the disproportionation of formic acid may produce formaldehyde that hydroxymethylates uracil in the first step of the conversion process. The experiments are supplemented by quantum chemical modeling of the reaction pathway, supporting the plausibility of the mechanism suggested by Saladino and coworkers.

Spontaneous butenolide ring formation of pregnane-21-O-malonyl hemiesters under mild reaction conditions is facilitated by the 14β-hydroxy group present in all natural cardenolides

Tetrahedron ◽  
2016 ◽  
Vol 72 (30) ◽  
pp. 4556-4563 ◽  
Author(s):  
R.M. Pádua ◽  
N. Meitinger ◽  
M. Hennemann ◽  
P. Schebitz ◽  
R. Waibel ◽  
...  
Keyword(s):  
Hydroxy Group ◽  
Ring Formation ◽  
Reaction Conditions

scholarly journals A combined experimental and theoretical study on the reactivity of nitrenes and nitrene radical anions

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Yujing Guo ◽  
Chao Pei ◽  
Rene M. Koenigs
Keyword(s):  
Radical Anion ◽  
Room Temperature ◽  
Theoretical Study ◽  
Transition Metal Catalysts ◽  
Transfer Reactions ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Nitrene Transfer ◽  
Triplet Nitrene ◽  
Nitrogen Bonds

AbstractNitrene transfer reactions represent one of the key reactions to rapidly construct new carbon-nitrogen bonds and typically require transition metal catalysts to control the reactivity of the pivotal nitrene intermediate. Herein, we report on the application of iminoiodinanes in amination reactions under visible light photochemical conditions. While a triplet nitrene can be accessed under catalyst-free conditions, the use of a suitable photosensitizer allows the access of a nitrene radical anion. Computational and mechanistic studies rationalize the access and reactivity of triplet nitrene and nitrene radical anion and allow the direct comparison of both amination reagents. We conclude with applications of both reagents in organic synthesis and showcase their reactivity in the reaction with olefins, which underline their markedly distinct reactivity. Both reagents can be accessed under mild reaction conditions at room temperature without the necessity to exclude moisture or air, which renders these metal-free, photochemical amination reactions highly practical.

scholarly journals Synthesis of Pyrazolo-Fused 4-Azafluorenones in an Ionic Liquid. Mechanistic Insights by Joint Studies Using DFT Analysis and Mass Spectrometry

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 820
Author(s):  
Efraín Polo ◽  
Valentina Arce-Parada ◽  
Xaviera A. López-Cortés ◽  
Jesús Sánchez-Márquez ◽  
Alejandro Morales-Bayuelo ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Density Functional ◽  
Room Temperature ◽  
Theoretical Study ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
Conceptual Density Functional Theory ◽  
Functional Theory ◽  
Three Component Reaction ◽  
Work Up

A series of pyrazolo-fused 4-azafluorenones (indeno[1,2-b]pyrazolo[4,3-e]pyridines, IPP) were synthesized via the three-component reaction between arylaldehydes, 3-methyl-1H-pyrazol-5-amine and 1,3-indanedione in an ionic liquid as a catalyst at room temperature. The applied synthetic route has the advantages of easy work-up under mild reaction conditions presenting moderate yields and an environmentally benign procedure. A theoretical study based on conceptual-density functional theory has been done, bond reactivity indices have been calculated and an electrophilic and nucleophilic character of localized orbitals has been determined to analyze the possible electronic mechanisms.

Norbornene in Organic Synthesis

Synthesis ◽  
2018 ◽  
Vol 50 (15) ◽  
pp. 2799-2823 ◽  
Author(s):  
Jianhui Huang ◽  
Caifeng Li ◽  
Liu Liu ◽  
Xuegang Fu
Keyword(s):  
Ring Opening ◽  
Membered Ring ◽  
Ring Formation ◽  
Oxidation Reactions ◽  
Organic Transformations ◽  
Substitution Reactions ◽  
Reaction Conditions ◽  
Multistep Synthesis ◽  
Palladium Catalyzed

The norbornene skeleton possesses an alkene functionality with a fixed conformation, and represents unique reactivity. The use of norbornene and analogues as substrates is overviewed; reactivities are discussed as well as the role of norbornenes as ligands assisting modern organic transformations.1 Introduction2 Synthesis of Substituted Norbornenes2.1 Preparation of Functionalized Norbornenes by Deprotonation and Substitution Reactions2.2 Preparation of Functionalized Norbornenes under Palladium-Catalyzed­ Reaction Conditions2.3 Alkylation of Norbornene2.4 Multistep Synthesis3 Synthesis of Substituted Norbornanes3.1 Three-Membered-Ring Formation3.2 Formation of Four-Membered Rings3.3 Five- and Six-Membered Ring Formation3.4 Syntheses of Difunctionalized Norbornanes4 Synthesis of Cyclopentanes4.1 Oxidation Reactions4.2 Ring-Opening Cross Metathesis (ROCM)4.3 Ring-Opening Metathesis Polymerization (ROMP)4.4 Palladium-Catalyzed Ring-Opening of Norbornene5 Norbornene-Mediated Reactions5.1 Palladium Insertion into Carbon–Halide Bonds5.2 Palladium Insertion into N–H and C–H Bonds5.3 Norbornene as Ligand in Mediated Reactions6 Conclusion

Mechanistic insight into the selective cyclization of arylnitrones to indolines via Rh(iii) catalyst: a theoretical study

RSC Advances ◽  
2016 ◽  
Vol 6 (28) ◽  
pp. 23265-23271 ◽  
Author(s):  
Tao Liu ◽  
Xiao-Wen Zheng ◽  
Ling-Li Han ◽  
Ya-Ping Li ◽  
Shu-Min Han ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Study ◽  
Coupling Reaction ◽  
Dft Study ◽  
Reaction Conditions ◽  
Functional Theory ◽  
Mechanistic Insight ◽  
Insight Into

A density functional theory (DFT) study was performed to understand detailed mechanisms for the Rh(iii)-catalyzed coupling reaction of phenylnitrone with diphenylacetylene in different reaction conditions.

Hydroboration of 1,1'-Bi(cyclopent-1-ene) and 3,3'-Biindene: Experimental and Theoretical Study

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1611-1626 ◽  
Author(s):  
Jaroslav Kvíčala ◽  
Ondřej Baszczyňski ◽  
Alena Krupková ◽  
Denisa Stránská
Keyword(s):  
Single Crystal ◽  
Nmr Spectra ◽  
Theoretical Study ◽  
Major Product ◽  
Reaction Conditions ◽  
Dft Methods ◽  
X Ray ◽  
Preferential Formation ◽  
H Nmr

Hydroboration of bi(cyclopent-1-ene) (1) or 3,3'-biindene (2) with borane, thexylborane or (-)-isopinocampheylborane afforded, regardless of reaction conditions, meso-isomers of polycyclic 1,4-diols 3a, 4a as the main products. No reaction was observed with 9-BBN. The structure of the major product 4a, as well as of the minor racemic product 4b was assigned based on 1H NMR spectra of the corresponding Mosher's diesters 5a-5c. Finally, the stereochemistry of the product 4a was confirmed by a single-crystal X-ray analysis of the corresponding dimesylate 6. To elucidate preferential formation of the meso-isomers, complexes of monohydroborated intermediate with borane were studied theoretically by DFT methods.

Experimental and theoretical study of the photochemical and thermal decomposition of maleic and dichloromaleic anhydrides

2002 ◽  
Vol 80 (5) ◽  
pp. 455-461 ◽  
Author(s):  
A Ionescu ◽  
N Piétri ◽  
M Hillebrand ◽  
M Monnier ◽  
J P Aycard
Keyword(s):  
Thermal Decomposition ◽  
Ir Spectroscopy ◽  
Photochemical Reaction ◽  
Theoretical Study ◽  
Thermal Reaction ◽  
Mo Calculations ◽  
Reaction Conditions ◽  
Decomposition Processes ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The photochemical and thermal behavior of maleic anhydride 1a and dichloromaleic anhydride 1b, in cryogenic matrix were investigated by means of FT-IR spectroscopy. The ketenylcarbenes represent the key intermediate in the decomposition processes of the anhydrides, even if they were not observed experimentally. The yields of the different products depend on the thermal or photochemical reaction conditions. The main photochemical products obtained from 1a were cyclopropenone and acetylene, whereas the major products from 1b were dichlorocyclopropenone and dichloroacetylene, along with small quantities of dichloropropadienone. The thermal reaction leads to dichloro propa dienone, CO, and CO2. MO calculations performed at the HF/6-31G*//HF/6-31G* level support the experimental mechanisms.Key words: photolysis, thermolysis, ab initio calculations, cryogenic matrix, ketenylcarbenes.

Evolution of CH3NO2/Si interfacial chemistry under reaction conditions: a combined experimental and theoretical study

2017 ◽  
Vol 53 (23) ◽  
pp. 3342-3345 ◽  
Author(s):  
Xueqiang Zhang ◽  
Chen-Guang Wang ◽  
Wei Ji ◽  
Sylwia Ptasinska
Keyword(s):  
Density Functional Theory ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Theoretical Study ◽  
Ambient Pressure ◽  
Dissociative Adsorption ◽  
Interfacial Chemistry ◽  
Reaction Conditions ◽  
Functional Theory ◽  
X Ray

Dissociative adsorption of CH3NO2 onto a Si(100)-2 × 1 surface is studied using ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and density functional theory (DFT) calculations.

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