scholarly journals Theoretical Evaluation of the Carbene-Based Site-Selectivity in Gold(III)-Catalyzed Annulations of Alkynes with Anthranils

2021 ◽  
Author(s):  
Kaifeng Wang ◽  
Qiao Wu ◽  
Siwei Bi ◽  
Lingjun Liu ◽  
Guang Chen ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Theoretical Evaluation ◽  
Site Selectivity ◽  
Substitution Mechanism

The gold(III)-catalyzed annulations of alkynes with anthranils were evaluated using DFT calculations. A unified rationale for the Br-migration on α-imino gold(III)-carbene was proposed, from which an unprecedented “N-donation/abstraction substitution” mechanism...

scholarly journals LAPONITE®-pilocarpine hybrid material: experimental and theoretical evaluation of pilocarpine conformation

RSC Advances ◽  
2017 ◽  
Vol 7 (44) ◽  
pp. 27290-27298 ◽  
Author(s):  
Vanessa R. R. Cunha ◽  
Filipe C. D. A. Lima ◽  
Vanessa Y. Sakai ◽  
Leiz M. C. Véras ◽  
José R. S. A. Leite ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Conformational Changes ◽  
Hybrid Material ◽  
Theoretical Evaluation

DFT calculations were applied to evaluate conformational changes of protonated pilocarpine after immobilization into LAPONITE®.

scholarly journals Ligand and solvent control of selectivity in the C–H activation of a pyridylimine-substituted 1-naphthalene; a combined synthetic and computational study

2018 ◽  
Vol 47 (33) ◽  
pp. 11680-11690
Author(s):  
Rena Simayi ◽  
Simone M. Gillbard ◽  
Warren B. Cross ◽  
Eric G. Hope ◽  
Kuldip Singh ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Computational Study ◽  
Site Selectivity ◽  
Solvent Control ◽  
Experimental Findings ◽  
Chloride Salts ◽  
Substituted 1

The site-selectivity of C–H activation in a 1-substituted naphthalene is explored using palladium(ii) chloride salts; the experimental findings are fully supported by DFT calculations.

scholarly journals Computational study on palladium-catalyzed alkenylation of remote δ-C(sp3)–H bonds with alkynes: a new understanding of mechanistic insight and origins of site-selectivity

RSC Advances ◽  
2018 ◽  
Vol 8 (53) ◽  
pp. 30186-30190 ◽  
Author(s):  
Hui-Min Yan ◽  
Ye Tian ◽  
Niu Li ◽  
Rong Chang ◽  
Zhu-Xia Zhang ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Computational Study ◽  
Mechanistic Insight ◽  
Site Selectivity ◽  
Palladium Catalyzed

Palladium-catalyzed alkenylation of δ-C(sp3)–H bonds with alkynes was conducted by DFT calculations, showing that the dimeric Pd2(OAc)4 mechanism reproduces experimental observations well.

scholarly journals Unconventional mechanism and selectivity of the Pd-catalyzed C–H bond lactonization in aromatic carboxylic acid

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Li-Ping Xu ◽  
Shaoqun Qian ◽  
Zhe Zhuang ◽  
Jin-Quan Yu ◽  
Djamaladdin G. Musaev
Keyword(s):  
Controlling Factors ◽  
Environmentally Benign ◽  
Oxidation Reactions ◽  
Aromatic Carboxylic Acid ◽  
Research Mission ◽  
Site Selectivity ◽  
Substitution Mechanism ◽  
Rate Limiting ◽  
Base Substrate ◽  
Formation Step

AbstractThe search for more effective and highly selective C–H bond oxidation of accessible hydrocarbons and biomolecules is a greatly attractive research mission. The elucidating of mechanism and controlling factors will, undoubtedly, help to broaden scope of these synthetic protocols, and enable discovery of more efficient, environmentally benign, and highly practical new C–H oxidation reactions. Here, we reveal the stepwise intramolecular SN2 nucleophilic substitution mechanism with the rate-limiting C–O bond formation step for the Pd(II)-catalyzed C(sp3)–H lactonization in aromatic 2,6-dimethylbenzoic acid. We show that for this reaction, the direct C–O reductive elimination from both Pd(II) and Pd(IV) (oxidized by O2 oxidant) intermediates is unfavorable. Critical factors controlling the outcome of this reaction are the presence of the η3-(π-benzylic)–Pd and K+–O(carboxylic) interactions. The controlling factors of the benzylic vs ortho site-selectivity of this reaction are the: (a) difference in the strains of the generated lactone rings; (b) difference in the strengths of the η3-(π-benzylic)–Pd and η2-(π-phenyl)–Pd interactions, and (c) more pronounced electrostatic interaction between the nucleophilic oxygen and K+ cation in the ortho-C–H activation transition state. The presented data indicate the utmost importance of base, substrate, and ligand in the selective C(sp3)–H bond lactonization in the presence of C(sp2)–H.

scholarly journals Hydration of α-UO3 following storage under controlled conditions of temperature and relative humidity

2020 ◽  
Vol 49 (30) ◽  
pp. 10452-10462 ◽  
Author(s):  
Marianne P. Wilkerson ◽  
Sarah C. Hernandez ◽  
W. Tyler Mullen ◽  
Andrew T. Nelson ◽  
Alison L. Pugmire ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Dft Calculations ◽  
Chemical Speciation ◽  
Experimental Measurements ◽  
Theoretical Evaluation ◽  
Controlled Conditions

Experimental measurements and theoretical evaluation of changes in chemical speciation of α-UO3 using XRD, EXAFS, TGA, and DFT calculations.

scholarly journals Site Selectivity in Pd-Catalyzed Reactions of α-Diazo-α-(methoxycarbonyl)acetamides: Effects of Catalysts and Substrate Substitution in the Synthesis of Oxindoles and β-Lactams

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3551 ◽  
Author(s):  
Daniel Solé ◽  
Ferran Pérez-Janer ◽  
Arianna Amenta ◽  
M.-Lluïsa Bennasar ◽  
Israel Fernández
Keyword(s):  
Dft Calculations ◽  
Reaction Mechanisms ◽  
The Other ◽  
Oxidation States ◽  
Other Hand ◽  
Site Selectivity ◽  
Catalyst Type ◽  
Catalyzed Reactions ◽  
Insight Into

The Pd-catalyzed intramolecular carbene C–H insertion of α-diazo-α-(methoxycarbonyl)acetamides to prepare oxindoles as well as β-lactams was studied. In order to identify what factors influence the selectivity of the processes, we explored how the reactions are affected by the catalyst type, using two oxidation states of Pd and a variety of ligands. It was found that, in the synthesis of oxindoles, ((IMes)Pd(NQ))2 can be used as an alternative to Pd2(dba)3 to catalyze the carbene CArsp2–H insertion, although it was less versatile. On the other hand, it was demonstrated that the Csp3–H insertion leading to β-lactams can be effectively promoted by both Pd(0) and Pd(II) catalysts, the latter being most efficient. Insight into the reaction mechanisms involved in these transformations was provided by DFT calculations.

Palladium-catalyzed C–H activation of anisole with electron-deficient auxiliary ligands: a mechanistic investigation

2020 ◽  
Vol 18 (30) ◽  
pp. 5857-5866 ◽  
Author(s):  
Xinyu Xu ◽  
Kezhi Chen
Keyword(s):  
Dft Calculations ◽  
Site Selectivity ◽  
Mechanistic Investigation ◽  
Palladium Catalyzed

In this work, the experimentally observed site-selectivity and ligand choice of Yu's meta-arylation reaction were rationalized through DFT calculations.

Chelation-assisted transition metal-catalysed C–H chalcogenylations

2020 ◽  
Vol 7 (8) ◽  
pp. 1022-1060 ◽  
Author(s):  
Wenbo Ma ◽  
Nikolaos Kaplaneris ◽  
Xinyue Fang ◽  
Linghui Gu ◽  
Ruhuai Mei ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Advances ◽  
Site Selectivity ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

This review summarizes recent advances in C–S and C–Se formations via transition metal-catalyzed C–H functionalization utilizing directing groups to control the site-selectivity.

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