scholarly journals Selenoxide Elimination Triggers Enamine Hydrolysis to Primary and Secondary Amines: A Combined Experimental and Theoretical Investigation

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2770
Author(s):  
Giovanni Ribaudo ◽  
Marco Bortoli ◽  
Erika Oselladore ◽  
Alberto Ongaro ◽  
Alessandra Gianoncelli ◽  
...  

We discuss a novel selenium-based reaction mechanism consisting in a selenoxide elimination-triggered enamine hydrolysis. This one-pot model reaction was studied for a set of substrates. Under oxidative conditions, we observed and characterized the formation of primary and secondary amines as elimination products of such compounds, paving the way for a novel strategy to selectively release bioactive molecules. The underlying mechanism was investigated using NMR, mass spectrometry and density functional theory (DFT).

2019 ◽  
Vol 484 (3) ◽  
pp. 307-311
Author(s):  
A. K. Dadayan ◽  
Yu. A. Borisov ◽  
E. V. Bocharov ◽  
Yu. A. Zolotarev ◽  
I. Yu. Nagaev ◽  
...  

The reaction of spillover hydrogen (SH) with cyclopropylglycine (cPG) in high-temperature solid-state catalytic hydrogen isotope exchange (HTCIE) has been studied experimentally and using density functional theory (DFT). NMR spectroscopy and mass spectrometry have shown a high regioselectivity and stereoselectivity for the reaction of spillover hydrogen with cPG fragments. The Gly fragment has been shown to be the most reactive in HTCIE, for which high stereoselectivity of substitution of hydrogen by deuterium has been demonstrated.


2018 ◽  
Vol 96 (12) ◽  
pp. 1071-1078
Author(s):  
Vahideh Zadsirjan ◽  
Sayyed Jalil Mahdizadeh ◽  
Majid M. Heravi ◽  
Masumeh Heydari

A novel series of N-functionalized 4-aryl-tetrahydrobiquinoline-2,5-(1H,3H)-diones were synthesized in high yields by a one-pot three-component reaction involving 2-chloroquinoline-3-carbaldehydes, Meldrum’s acid, and enaminones (dimedone-based enaminones) in the presence of K2CO3 in CH3CN under reflux condition. To gain a deep insight on the mechanism of the reaction, an extensive series of quantum mechanics calculations in the framework of density functional theory (DFT) were carried out for supporting the suggested reaction pathway.


2021 ◽  
Vol 18 ◽  
Author(s):  
Mirza Arfan Yawer ◽  
Shehar Bano ◽  
Muhammad Saleem ◽  
Affiefa Yawer ◽  
Riaz Hussain ◽  
...  

Aims: The aim of present research was to synthesize glycoluril derivative 2,4-Bis(4-cyanobenzyl)glycoluril through convergent scheme. Background: For this purpose Sandmeyer reaction procedure was employed for the synthesis of said compound. The structure of the pure compound was confirmed by using different spectroscopic techniques such as 1H-NMR, 13C-NMR and (HR-MS) Mass spectrometry. Objective: Convergent synthesis of 2,4-BIS (4-CYANOBENZYL)GLYCOLURIL USING SANDMEYER REACTION and urease inhibition study. Methods: The structure of the pure compound was confirmed by using different spectroscopic techniques such as 1H-NMR, 13C-NMR and (HR-MS) Mass spectrometry. The electronic properties of newly synthesized compound and thiourea were determined by using density functional theory. Results: Furthermore compound was evaluated against urease enzyme and was found to be potent inhibitors with IC50 value of 11.5 ± 1.50 µM when compared with standard inhibitor thiourea (IC50 = 21.0 ± 1.90 µM). Compound may serve as lead compound for the synthesis of new cyano based bambusuril in future with enhanced biological properties. Conclusion: We have synthesized a new glycoluril derivative 2,4-Bis(4-cyanobenzyl)glycoluril by the sandmeyer reaction. It has obtained in the form of light yellowish powder in good yield (96%). Glycoluril based macrocycles have been used in various fields. Starting from the 2,4-Bis(4-nitrobenzyl)glycoluril (already reported compound) which has undergone reduction (CH3OH,Pt/C) , diazotization (NaNO2/HCl), cyanation (CuCl/KCN) respectively in order to synthesize the desired new glycoluril derivative. The obtained product will be used as a building block for the synthesis of the cyano based bambusuril marcocycle in future. The yield of the obtained product has been monitored by using different amount of cyanating reagent but the best results shown by the use of 4 mmol of CuCl/KCN. KCN with CuCl assisted the conversion of diazo group into cyano group with enhanced yield when used in excess amount. It act as a catalyst. Solubility characteristic of 2,4-Bis(4-cyanobenzyl)glycoluril has determined also in different organic solvents. 1H NMR technique proved to be very helpful for the structure determination of our desired product. Benzylic protons give signals at 7.5 ppm and 7.8 ppm respectively. The downfield peaks confirm about the presence of CN group near the benzylic protons. Methine protons show signal at 5.2 ppm which ensures about the basic skeleton of glycoluril. Ureidyl protons also confirm the synthesis of the heterocyclic 2,4-Bis(4-cyanobenzyl)glycoluril compound. The negative and positive electrostatic potential sites, molecular descriptors, and charge density distribution of frontier molecular orbitals are revealing that 4a with promising sites for electrophilic and nucleophilic attacks would result to enhance the urease inhbition which is in good agreement with the experimental data.


Synthesis ◽  
2019 ◽  
Vol 52 (08) ◽  
pp. 1247-1252 ◽  
Author(s):  
Sumin Lee ◽  
Young Jin Jang ◽  
Erik J. T. Phipps ◽  
Honghui Lei ◽  
Tomislav Rovis

We report a three-component diamination of simple unactivated alkenes using an electrophilic nitrene source and amine nucleo­philes. The reaction provides rapid access to 1,2-vicinal diamines from terminal alkenes through a one-pot protocol. The transformation proceeds smoothly with excellent tolerance for a broad array of primary and secondary amines, affording the desired products in good yield and regioselectivity. The mechanism is proposed to proceed through a Rh(III)-catalyzed aziridination of alkenes with subsequent ring opening by primary or secondary amines.


1982 ◽  
Vol 65 (5) ◽  
pp. 1066-1072
Author(s):  
Brian D Ripley ◽  
Bruce J French ◽  
Lloyd V Edgington

Abstract An analytical method is described for the determination of mono- and dialkylamines in foodstuffs. Amines are derivatized to their pentafluorobenzamides which may be separated by gas chromatography (GC) and determined using an N-P detector. Analysis of the derivatives by GC-mass spectrometry indicated they were all mono-substituted. The amines were isolated from foodstuffs by alkaline distillation of ≥75% sample volume. The distribution of dimethylamine (DMA) in distillate volumes indicated 2 maxima from barley and malt, which could represent 2 or more sources of DMA. DMA concentrations of 6.6-8.8 ppm in barley, 11 ppm in malt, and 1.2 ppm in beer are higher than previously reported.


2020 ◽  
Vol 13 (05) ◽  
pp. 2041001 ◽  
Author(s):  
Junchi Chen ◽  
Lingfang Liu ◽  
Haile Liu ◽  
Yonghui Li ◽  
Junying Wang ◽  
...  

Metal clusters have attracted wide interests due to their unique electronic and optical properties, but the low luminescence quantum yield (QY) prevents them from potential biomedical applications. In this work, silver-doped Au nanoclusters (NCs) are shown to be able to improve the QY of metal clusters. We succeeded in synthesizing ultrabright glutathione (GSH) protected AuAg clusters with 10.8% QY by a one-pot route. Their florescence is about 7.5 times brighter than pure Au NCs, with super photostability and good biocompatibility in physiological environment. Based on density functional theory (DFT) calculations, we investigated the electronic structures and optical properties of the AuAg NCs. The results show that the increase of the density of states of the lowest unoccupied molecular orbital (LUMO) leads to the fluorescence enhancement. In addition, two-photon excitation fluorescence imaging has been performed to show their great potential for biomedicine.


2018 ◽  
Vol 5 (23) ◽  
pp. 3374-3381 ◽  
Author(s):  
Feiyun Jia ◽  
Jiewei Luo ◽  
Bo Zhang

The silver-mediated one-pot synthesis of 3-trifluoromethylpyrazoles using a traceless directing group was investigated by density functional theory (DFT) calculations.


Sign in / Sign up

Export Citation Format

Share Document