Mechanistic insight into the organocalcium-mediated nucleophilic alkylation of benzene and further rational design

2020 ◽  
Vol 10 (4) ◽  
pp. 950-958 ◽  
Author(s):  
Xuefei Zhao ◽  
Dengmengfei Xiao ◽  
Xianlu Cui ◽  
Chaoqun Chai ◽  
Lili Zhao

DFT calculations disclosed the mechanism of the target reaction and the origin of unusual nucleophilicity of organocalcium. More reactive analogues were designed.

2015 ◽  
Vol 112 (18) ◽  
pp. 5579-5584 ◽  
Author(s):  
Galina V. Dubacheva ◽  
Tine Curk ◽  
Rachel Auzély-Velty ◽  
Daan Frenkel ◽  
Ralf P. Richter

Specific targeting is common in biology and is a key challenge in nanomedicine. It was recently demonstrated that multivalent probes can selectively target surfaces with a defined density of surface binding sites. Here we show, using a combination of experiments and simulations on multivalent polymers, that such “superselective” binding can be tuned through the design of the multivalent probe, to target a desired density of binding sites. We develop an analytical model that provides simple yet quantitative predictions to tune the polymer’s superselective binding properties by its molecular characteristics such as size, valency, and affinity. This work opens up a route toward the rational design of multivalent probes with defined superselective targeting properties for practical applications, and provides mechanistic insight into the regulation of multivalent interactions in biology. To illustrate this, we show how the superselective targeting of the extracellular matrix polysaccharide hyaluronan to its main cell surface receptor CD44 is controlled by the affinity of individual CD44–hyaluronan interactions.


2019 ◽  
Vol 43 (22) ◽  
pp. 8634-8643 ◽  
Author(s):  
Feiyun Jia ◽  
Bo Zhang

By using DFT calculations, we disclose the reason why silver(i) catalytically promotes the activity and regioselectivity of the cycloaddition of 1,4-disubstituted-1,2,3-triazoles.


2021 ◽  
Author(s):  
Rohan Pokratath ◽  
Dietger Van den Eynden ◽  
Susan Rudd Cooper ◽  
Jette Katja Mathiesen ◽  
Valérie Waser ◽  
...  

One can nowadays readily generate monodisperse colloidal nanocrystals, but a retrosynthetic analysis is still not possible since the underlying chemistry is often poorly understood. Here, we provide insight into the reaction mechanism of colloidal zirconia and hafnia nanocrystals synthesized from metal chloride and metal isopropoxide. We identify the active precursor species in the reaction mixture through a combination of nuclear magnetic resonance spectroscopy (NMR), density functional theory (DFT) calculations, and pair distribution function (PDF) analysis. We gain insight into the interaction of the surfactant, tri-n-octylphosphine oxide (TOPO), and the different precursors. Interestingly, we identify a peculiar X-type ligand redistribution mechanism that can be steered by the relative amount of Lewis base (L-type). We further monitor how the reaction mixture decomposes using solution NMR and gas chromatography, and we find that ZrCl4 is formed as a by-product of the reaction, limiting the reaction yield. The reaction proceeds via two competing mechanisms: E1 elimination (dominating) and SN1 substitution (minor). Using this new mechanistic insight, we adapted the synthesis to optimize the yield and gain control over nanocrystal size. These insights will allow the rational design and synthesis of complex oxide nanocrystals.


2020 ◽  
Vol 22 (41) ◽  
pp. 23869-23877
Author(s):  
Yan Li ◽  
Ning Liu ◽  
Chengna Dai ◽  
Ruinian Xu ◽  
Bin Wu ◽  
...  

Present work investigates the kinetic role of H2 during Ni surface diffusion and deposition to generate branched Ni nanostructures by employing density functional theory (DFT) calculations and ab initio molecule dynamic (AIMD) simulations.


Author(s):  
Xiaoqian He ◽  
Lei Zhu ◽  
Dan Heng ◽  
Fenru Liu ◽  
Shihan Liu ◽  
...  

Density functional theory (DFT) calculations have been performed to provide mechanistic insight into the Rh/Cu co-catalyzed multicomponent annulation of indoles, diazo compounds, and α,β-unsaturated esters.


RSC Advances ◽  
2019 ◽  
Vol 9 (18) ◽  
pp. 10201-10210 ◽  
Author(s):  
Go Hamasaka ◽  
Hiroaki Tsuji ◽  
Masahiro Ehara ◽  
Yasuhiro Uozumi

Mechanistic studies on the organoborane-catalyzed transfer hydrogenation of nonactivated aldehydes with a Hantzsch ester as a synthetic NADPH analogue were performed by NMR experiments and DFT calculations.


Nanoscale ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 5125-5138
Author(s):  
Turbasu Sengupta ◽  
Jin Suk Chung ◽  
Sung Gu Kang

The reaction pathways of ethylene hydrogenation on pristine (Aun, n = 8 and 20) and rhodium-doped (AunRh) gold clusters are explored by DFT calculations.


2015 ◽  
Vol 13 (30) ◽  
pp. 8251-8260 ◽  
Author(s):  
Weirong Wu ◽  
Yuxia Liu ◽  
Siwei Bi

DFT calculations are performed to understand the conjugated N–N bond cleavage by Rh(iii)-catalyzed redox-neutral C–H activation of pyrazolones with PhCCPh.


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