Theoretical Calculation on Regioselectivity and Solvation Effect in B-H Activation of O-carborane Guided by Directing Group

2021 ◽  
Author(s):  
Hui Li ◽  
Wanyong Tang ◽  
Zifan Ma
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Theoretical Calculation ◽  
Solvation Effect ◽  
Directing Group

This paper focuses on uncovering the regioselectivity, directing group, ligand, solvation effect in B-H activation that investigated by DFT calculations. The reaction mechanism was investigated in vacuum, and the advantage...

Mechanism and origins of the directing group-controlled endo- versus exo-selectivity of iridium-catalysed intramolecular hydroalkenylation of 1,1-disubstituted alkenes

2018 ◽  
Vol 54 (21) ◽  
pp. 2678-2681 ◽  
Author(s):  
Yanmin Lang ◽  
Mei Zhang ◽  
Yang Cao ◽  
Genping Huang
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Directing Group

The reaction mechanism and the important role of directing groups in determining selectivity have been investigated by means of DFT calculations.

Reactions of an Aluminium(I) Reagent with 1,2-, 1,3- and 1,5-Dienes: Dearomatisation, Reversibility, and a Pericyclic Mechanism

2019 ◽  
Author(s):  
Clare Bakewell ◽  
Martí Garçon ◽  
Richard Y Kong ◽  
Louisa O'Hare ◽  
Andrew J. P. White ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Transition State ◽  
Reaction Pathways ◽  
Aromatic Rings ◽  
Aromatic Character ◽  
Pericyclic Reaction

The reactions of an aluminium(I) reagent with a series of 1,2-, 1,3- and 1,5-dienes are reported. In the case of 1,3-dienes the reaction occurs by a pericyclic reaction mechanism, specifically a cheletropic cycloaddition, to form aluminocyclopentene containing products. This mechanism has been interrogated by stereochemical experiments and DFT calculations. The stereochemical experiments show that the (4+1) cycloaddition follows a suprafacial topology, while calculations support a concerted albeit asynchronous pathway in which the transition state demonstrates aromatic character. Remarkably, the substrate scope of the (4+1) cycloaddition includes dienes that are either in part, or entirely, contained within aromatic rings. In these cases, reactions occur with dearomatisation of the substrate and can be reversible. In the case of 1,2- or 1,5-dienes complementary reactivity is observed; the orthogonal nature of the C=C π-bonds (1,2-diene) and the homoconjugated system (1,5-diene) both disfavour a (4+1) cycloaddition. Rather, reaction pathways are determined by an initial (2+1) cycloaddition to form an aluminocyclopropane intermediate which can in turn undergo insertion of a further C=C π-bond leading to complex organometallic products that incorporate fused hydrocarbon rings.

Reaction mechanism of synthetic thorium sulfides: theoretical calculation study

2020 ◽  
Vol 26 (6) ◽  
Author(s):  
Huifeng Zhao ◽  
Peng Li ◽  
Meigang Duan ◽  
Feng Xie ◽  
Jie Ma
Keyword(s):  
Reaction Mechanism ◽  
Theoretical Calculation

scholarly journals Catalytic mechanism of the colistin resistance protein MCR-1

2021 ◽  
Author(s):  
Reynier Suardíaz ◽  
Emily Lythell ◽  
Philip Hinchliffe ◽  
Marc van der Kamp ◽  
James Spencer ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Antimicrobial Resistance ◽  
Dft Calculations ◽  
Catalytic Reaction ◽  
Catalytic Mechanism ◽  
Cluster Models ◽  
Colistin Resistance ◽  
Resistance Protein ◽  
Catalytic Reaction Mechanism

Elucidation of the catalytic reaction mechanism of MCR-1 enzyme, responsible for the antimicrobial resistance to colistin, using DFT calculations on cluster models.

scholarly journals Palladium-Catalysed C–F Alumination of Fluorobenzenes: Mechanistic Diversity and Origin of Selectivity

2020 ◽  
Author(s):  
Feriel Rekhroukh ◽  
Wenyi Chen ◽  
Ryan Brown ◽  
Andrew J. P. White ◽  
Mark Crimmin
Keyword(s):  
Dft Calculations ◽  
Bond Activation ◽  
Oxidative Addition ◽  
Fluorine Content ◽  
Model Potential ◽  
Heterometallic Complex ◽  
Experimental Support ◽  
Highly Active ◽  
Reaction Proceeds ◽  
Directing Group

A palladium pre-catalyst, [Pd(PCy<sub>3</sub>)<sub>2</sub>] is reported for the efficient and selective C–F alumination of fluorobenzenes with the aluminium(I) reagent [{(ArNCMe)<sub>2</sub>CH}Al] (<b>1</b>, Ar = 2,6-di-iso-propylphenyl). The catalytic protocol results in the transformation of sp<sup>2</sup> C–F bonds to sp<sup>2</sup> C–Al bonds and provides a route into reactive organoaluminium complexes (<b>2a-h</b>) from fluorocarbons. The catalyst is highly active. Reactions proceed within 5 minutes at 25 ºC (and at appreciable rates at even –50 ºC) and the scope includes low-fluorine-content substrates such as fluorobenzene, difluorobenzenes and trifluorobenzenes. The reaction proceeds with complete chemoselectivity (C–F vs C–H) and high regioselectivities ( >90% for C–F bonds adjacent to the most acidic C–H sites). The heterometallic complex [Pd(PCy<sub>3</sub>)(<b>1</b>)<sub>2</sub>] was shown to be catalytically competent. Catalytic C–F alumination proceeds with a KIE of 1.1–1.3. DFT calculations have been used to model potential mechanisms for C–F bond activation. These calculations suggest that two competing mechanisms may be in operation. Pathway 1 involves a ligand-assisted oxidative addition to [Pd(<b>1</b>)<sub>2</sub>] and leads directly to the product. Pathway 2 involves a stepwise C–H to C–F functionalisation mechanism in which the C–H bond is broken and reformed along the reaction coordinate, allowing it to act as a directing group for the adjacent C–F site. This second mechanism explains the experimentally observed regioselectivity. Experimental support for this C–H activation playing a key role in C–F alumination was obtained by employing [{(MesNCMe)<sub>2</sub>CH}AlH<sub>2</sub>] (<b>3</b>, Mes = 2,4,6-trimethylphenyl) as a reagent in place of 1. In this instance, the kinetic C–H alumination intermediate could be isolated. Under catalytic conditions this intermediate converts to the thermodynamic C–F alumination product.

scholarly journals Unprecedented η3-Coordination and Functionalization of the 2-Phosphaethynthiolate Anion at Lanthanum(III)

2021 ◽  
Author(s):  
Fabian A. Watt ◽  
Lukas Burkhardt ◽  
Roland Schoch ◽  
Stefan Mitzinger ◽  
Matthias Bauer ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Coordination Mode ◽  
Quantum Mechanical ◽  
Structural Comparison ◽  
Anion Complex ◽  
Steric Factors ◽  
Group 15 ◽  
Detailed Reaction Mechanism ◽  
The Ideal

We present the unprecedented <i>η</i>3-coordination of the 2-phosphaethynthiolate anion in the complex (PN)<sub>2</sub>La(SCP) (<b>2</b>) [PN = N-(2-(diisopropylphosphanyl)-4-methylphenyl)-2,4,6-trimethylanilide)]. Structural comparison with dinuclear thiocyanate bridged (PN)<sub>2</sub>La(<i>μ</i>-1,3-SCN)<sub>2</sub>La(PN)<sub>2</sub> (<b>3</b>) and azide bridged (PN)<sub>2</sub>La(<i>μ</i>-1,3-N3)<sub>2</sub>La(PN)<sub>2</sub> (<b>4</b>) complexes indicates that the [SCP]<sup>–</sup> coordination mode is mainly governed by electronic, rather than steric factors. Quantum mechanical investigations reveal large contributions of the antibonding π-orbital of the [SCP]<sup>–</sup> ligand to the LUMO of complex <b>2</b>, rendering it the ideal precursor for the first functionalization of the [SCP]<sup>–</sup> anion. Complex <b>2</b> was therefore reacted with CAACs which induced a selective rearrangement of the [SCP]<sup>–</sup> ligand to form the first CAAC stabilized group 15 – group 16 fulminate-type complexes (PN)<sub>2</sub>La{SPC(<sup>R</sup>CAAC)} (<b>5a,b</b>) (R = Ad, Me). A detailed reaction mechanism for the SCP to SPC isomerization is proposed based on DFT calculations.

The reactivity of stoichiometric tungsten oxide clusters towards carbon monoxide: the effects of cluster sizes and charge states

2015 ◽  
Vol 17 (17) ◽  
pp. 11499-11508 ◽  
Author(s):  
Shu-Juan Lin ◽  
Jing Cheng ◽  
Chang-Fu Zhang ◽  
Bin Wang ◽  
Yong-Fan Zhang ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Reaction Mechanism ◽  
Dft Calculations ◽  
Tungsten Oxide ◽  
Charge States

DFT calculations were carried out to study the reaction mechanism for tungsten oxide clusters with CO.

Palladium-catalyzed directing group assisted and regioselectivity reversed cyclocarbonylation of arylallenes with 2-iodoanilines

2021 ◽  
Author(s):  
Jian-Shu Wang ◽  
Lingyun Yao ◽  
Jun Ying ◽  
Xiaoling Luo ◽  
Xiao-Feng Wu
Keyword(s):  
Dft Calculations ◽  
Palladium Catalyzed ◽  
Directing Group

A palladium-catalyzed regioselective cyclocarbonylation of N-(2-pyridyl)sulfonyl (N-SO2Py)-2-iodoanilines with allenes was developed. The regioselectivity of arylallenes was reversed. Control experiments and DFT calculations were performed to understand the reaction details.

scholarly journals On the catalytic transfer hydrogenation of nitroarenes by a cubane-type Mo3S4 cluster hydride: disentangling the nature of the reaction mechanism

2019 ◽  
Vol 21 (31) ◽  
pp. 17221-17231 ◽  
Author(s):  
Vicent S. Safont ◽  
Iván Sorribes ◽  
Juan Andrés ◽  
Rosa Llusar ◽  
Mónica Oliva ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Transfer Hydrogenation ◽  
Catalytic Transfer Hydrogenation ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
Catalytic Transfer

Transfer hydrogenation cluster catalysis operates through a panoply of cycles, according to DFT calculations, affording a highly efficient catalyst.

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