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.

scholarly journals Mechanism, reactivity, and selectivity of the iridium-catalyzed C(sp3)–H borylation of chlorosilanes

2015 ◽  
Vol 6 (3) ◽  
pp. 1735-1746 ◽  
Author(s):  
Genping Huang ◽  
Marcin Kalek ◽  
Rong-Zhen Liao ◽  
Fahmi Himo
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations

DFT calculations are used to elucidate the reaction mechanism, the role of the chlorosilyl group, and primary vs. secondary and C(sp3)–H vs. C(sp2)–H selectivity of the iridium-catalyzed borylation of chlorosilanes.

Theoretical investigation on the hydrogen evolution reaction mechanism at MoS2 heterostructures: the essential role of the 1T/2H phase interface

2020 ◽  
Vol 10 (2) ◽  
pp. 458-465 ◽  
Author(s):  
Tian Zhang ◽  
Houyu Zhu ◽  
Chen Guo ◽  
Shoufu Cao ◽  
Chi-Man Lawrence Wu ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Hydrogen Evolution ◽  
Theoretical Investigation ◽  
Hydrogen Evolution Reaction ◽  
Basal Plane ◽  
Essential Role ◽  
Phase Interface

DFT calculations have been performed to study the HER mechanism at 1T/2H MoS2 heterostructures. The HER activity along the 1T/2H phase interface is comparable with those at the Mo-edge of 2H MoS2 and the basal plane of 1T MoS2.

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...

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.

Synthetic and Mechanistic Studies of a Versatile Heteroaryl Thioether Directing Group for Pd(II) Catalysis

2019 ◽  
Author(s):  
Andrew Romine ◽  
Kin Yang ◽  
Malkanthi Karunananda ◽  
Jason Chen ◽  
Keary Engle
Keyword(s):  
Mechanistic Studies ◽  
Salvianolic Acid ◽  
Wide Range ◽  
Computational Data ◽  
Synthetic Utility ◽  
Directing Group ◽  
High Yields ◽  
Julia Olefination ◽  
Reaction Progress Kinetic Analysis

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, arene C–H olefination was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a “masked olefin” directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C–H olefination as the key step.

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.

γ-Valerolactone-Introduced Controlled-Isomerization of Glucose for Lactic Acid Production over Sn-Beta Catalyst

2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Lactic Acid ◽  
Dft Calculations ◽  
Acid Production ◽  
Density Functional ◽  
Lactic Acid Production ◽  
Hydrothermal Conversion ◽  
Functional Theory ◽  
Environment Friendly

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...

scholarly journals The Activating Effect of Strong Acid for Pd-Catalyzed Directed C–H Activation by Concerted Metalation-Deprotonation Mechanism

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4083
Author(s):  
Heming Jiang ◽  
Tian-Yu Sun
Keyword(s):  
Activation Energy ◽  
Dft Calculations ◽  
Energy Barrier ◽  
Computational Study ◽  
Strong Acid ◽  
Activation Energy Barrier ◽  
Pd Catalysts ◽  
Acid Ligand ◽  
Strong Acids

A computational study on the origin of the activating effect for Pd-catalyzed directed C–H activation by the concerted metalation-deprotonation (CMD) mechanism is conducted. DFT calculations indicate that strong acids can make Pd catalysts coordinate with directing groups (DGs) of the substrates more strongly and lower the C–H activation energy barrier. For the CMD mechanism, the electrophilicity of the Pd center and the basicity of the corresponding acid ligand for deprotonating the C–H bond are vital to the overall C–H activation energy barrier. Furthermore, this rule might disclose the role of some additives for C–H activation.

scholarly journals The role of hypervalent iodine(iii) reagents in promoting alkoxylation of unactivated C(sp3)–H bonds catalyzed by palladium(ii) complexes

2021 ◽  
Author(s):  
Payam Abdolalian ◽  
Samaneh K. Tizhoush ◽  
Kaveh Farshadfar ◽  
Alireza Ariafard
Keyword(s):  
Dft Calculations ◽  
Oxidative Addition ◽  
Hypervalent Iodine

This work uses DFT calculations to explore Pd(ii)-catalysed iodine(iii)-mediated alkoxylation of unactivated C(sp3)–H bonds and reveals how important the isomerization is in triggering the oxidative addition of ArIX2 to Pd(ii).

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