scholarly journals Ruthenium-catalyzed, site-selective C–H activation: access to C5-substituted azaflavanone

RSC Advances ◽  
2020 ◽  
Vol 10 (52) ◽  
pp. 31570-31574
Author(s):  
Manickam Bakthadoss ◽  
Tadiparthi Thirupathi Reddy ◽  
Duddu S. Sharada
Keyword(s):  
Bond Activation ◽  
Keto Group ◽  
A Site ◽  
Site Selective ◽  
First Time

A site-selective ruthenium-catalyzed keto group assisted C–H bond activation of 2-aryl tetrahydroquinoline (azaflavanone) derivatives has been achieved with a variety of alkenes for the first time.

scholarly journals Heterogeneous Suzuki–Miyaura coupling of heteroaryl ester via chemoselective C(acyl)–O bond activation

RSC Advances ◽  
2019 ◽  
Vol 9 (30) ◽  
pp. 17266-17272 ◽  
Author(s):  
Hongpeng Ma ◽  
Chaolumen Bai ◽  
Yong-Sheng Bao
Keyword(s):  
Bond Activation ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Palladium Nanoparticle ◽  
Arylboronic Acids ◽  
Cross Coupling Reaction ◽  
Supported Palladium ◽  
A Site ◽  
Site Selective

A site-selective supported palladium nanoparticle catalyzed Suzuki–Miyaura cross-coupling reaction with heteroaryl esters and arylboronic acids as coupling partners was developed.

Chemical and Electrochemical Heteroepitaxial Growth of Chalcogenide Semiconductors from Solutions

1996 ◽  
Vol 451 ◽  
Author(s):  
D. Lincot ◽  
M. J. Furlong ◽  
M. Froment ◽  
R. Cortes ◽  
M. C. Bernard
Keyword(s):  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Basic Principles ◽  
Lattice Match ◽  
X Ray ◽  
Chalcogenide Semiconductors ◽  
Influence Of Temperature On ◽  
Deposition Processes ◽  
A Site ◽  
Site Selective

ABSTRACTChalcogenide semiconductors have been deposited epitaxially from aqueous solutions either chemically or electrochemically at growth rates of up to 0.7 μmhr−1. After recalling the basic principles of these deposition processes, results are presented concerning chemically deposited CdS on InP, GaP and CuInSe2 substrates, electrodeposited CdTe on InP, and CdSAnP heterostructures. Characterisation of these structures by RHEED, TEM, HRTEM, and glazing angle X ray diffraction allows to analyse the effects of substrate orientation, polarity, lattice match plus the influence of temperature on epitaxial growth. These results are discussed in terms of self organisation and a site selective growth mechanisms due to the free enegy of formation of each compound.

Cobalt/Lewis Acid Catalysis for Hydrocarbofunctionalization of Alkynes via Cooperative C–H Activation

2020 ◽  
Author(s):  
Chang-Sheng Wang ◽  
Sabrina Monaco ◽  
Anh Ngoc Thai ◽  
Md. Shafiqur Rahman ◽  
Chen Wang ◽  
...  
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Hydrogen Transfer ◽  
Acid Catalysis ◽  
Rate Limiting Step ◽  
Site Selectivity ◽  
Set Up ◽  
Site Selective ◽  
First Time ◽  
Rate Limiting

A catalytic system comprised of a cobalt-diphosphine complex and a Lewis acid (LA) such as AlMe3 has been found to promote hydrocarbofunctionalization reactions of alkynes with Lewis basic and electron-deficient substrates such as formamides, pyridones, pyridines, and azole derivatives through site-selective C-H activation. Compared with known Ni/LA catalytic system for analogous transformations, the present catalytic system not only feature convenient set up using inexpensive and bench-stable precatalyst and ligand such as Co(acac)3 and 1,3-bis(diphenylphosphino)propane (dppp), but also display distinct site-selectivity toward C-H activation of pyridone and pyridine derivatives. In particular, a completely C4-selective alkenylation of pyridine has been achieved for the first time. Mechanistic stidies including DFT calculations on the Co/Al-catalyzed addition of formamide to alkyne have suggested that the reaction involves cleavage of the carbamoyl C-H bond as the rate-limiting step, which proceeds through a ligand-to-ligand hydrogen transfer (LLHT) mechanism leading to an alkyl(carbamoyl)cobalt intermediate.

Theoretical and experimental studies of palladium-catalyzed site-selective C(sp3)−H bond functionalization enabled by transient ligands

2017 ◽  
Author(s):  
Haibo Ge ◽  
Lei Pan ◽  
Piaoping Tang ◽  
Ke Yang ◽  
Mian Wang ◽  
...  
Keyword(s):  
Bond Activation ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Bond Functionalization ◽  
Aliphatic Ketones ◽  
Site Selectivity ◽  
Mechanistic Investigation ◽  
Palladium Catalyzed ◽  
Metal Catalyzed ◽  
Site Selective

Transition metal-catalyzed selective C–H bond functionalization enabled by transient ligands has become an extremely attractive topic due to its economical and greener characteristics. However, catalytic pathways of this reaction process on unactivated sp<sup>3</sup> carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp<sup>3</sup>)–H bond activation with amino acids as transient ligands has been systematically conducted. The theoretical calculations showed that higher angle distortion of C(sp2)-H bond over C(sp3)-H bond and stronger nucleophilicity of benzylic anion over its aromatic counterpart, leading to higher reactivity of corresponding C(sp<sup>3</sup>)–H bonds; the angle strain of the directing rings of key intermediates determines the site-selectivity of aliphatic ketone substrates; replacement of glycine with β-alanine as the transient ligand can decrease the angle tension of the directing rings. Synthetic experiments have confirmed that β-alanine is indeed a more efficient transient ligand for arylation of β-secondary carbons of linear aliphatic ketones than its glycine counterpart.<br><br>

ChemInform Abstract: Non-Coordinating-Anion-Directed Reversal of Activation Site: Selective C-H Bond Activation of N-Aryl Rings.

ChemInform ◽  
2016 ◽  
Vol 47 (45) ◽  
Author(s):  
Dawei Wang ◽  
Xiaoli Yu ◽  
Xiang Xu ◽  
Bingyang Ge ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Bond Activation ◽  
Site Selective ◽  
Activation Site

A Site‐Selective C−N Bond Formation of 2,4‐Dichloro‐5 H ‐pyrano[2,3‐ d ]pyrimidines and Amide

2021 ◽  
Vol 6 (43) ◽  
pp. 12032-12035
Author(s):  
Jinjing Qin ◽  
Zhenhua Li ◽  
Yingyan Cao ◽  
Yuanyuan Xie ◽  
Weike Su
Keyword(s):  
Bond Formation ◽  
A Site ◽  
Site Selective

Abstract 1304: AbYlinkTM: A site-selective labeling method for preclinical imaging of therapeutic antibodies

2021 ◽  
Author(s):  
Viktoriia Postupalenko ◽  
Léo Marx ◽  
David Viertl ◽  
Natalia Gasilova ◽  
Mathilde Plantin ◽  
...  
Keyword(s):  
Therapeutic Antibodies ◽  
Selective Labeling ◽  
Preclinical Imaging ◽  
A Site ◽  
Site Selective ◽  
Labeling Method

Catalyst-Controlled Site-Selective N-H and C3-Arylation of Carba-zole via Carbene Transfer Reactions

2021 ◽  
Author(s):  
Sourav Sekhar Bera ◽  
Srishti Ballabh Bahukhandi ◽  
Claire Empel ◽  
Rene M Koenigs
Keyword(s):  
Transfer Reactions ◽  
Palladium Acetate ◽  
Direct Arylation ◽  
Carbene Transfer ◽  
A Site ◽  
Site Selective

A site-selective direct arylation reaction of carbazole and other N-heterocycles with diazo-naphthalen-2(1H)-ones has been developed. While Au(I)-NHC catalysts lead to selective C3-arylation, palladium acetate allows for selective N-H arylation, displaying...

Photoredox B–H Functionalization to Selective B–N(sp3) Coupling of nido-Carborane with Primary and Secondary Amines

2021 ◽  
Author(s):  
Hong Yan ◽  
Changsheng Lu ◽  
Ronghui Huang ◽  
Weijia Zhao ◽  
Shengwen Xu ◽  
...  
Keyword(s):  
Secondary Amines ◽  
Primary And Secondary Amines ◽  
Site Selective ◽  
First Time

Access to nido-carborane site-selective B–N(sp3) coupling by photoredox catalyzed B–H activation has been achieved for the first time, which leads to the synthesis of a series of nitrogen-containing nido-carboranes in...

Sign in / Sign up

Export Citation Format

Share Document