Non-coordinating-Anion-Directed Reversal of Activation Site: Selective C−H Bond Activation ofN-Aryl Rings

2016 ◽  
Vol 22 (25) ◽  
pp. 8663-8668 ◽  
Author(s):  
Dawei Wang ◽  
Xiaoli Yu ◽  
Xiang Xu ◽  
Bingyang Ge ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Bond Activation ◽  
Site Selective ◽  
Activation Site

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

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>

Carbon Dioxide-Driven Palladium-Catalyzed C–H Activation of Amines: A Unified Approach for the Arylation of Aliphatic and Aromatic Primary and Secondary Amines

Synlett ◽  
2019 ◽  
Vol 30 (05) ◽  
pp. 519-524 ◽  
Author(s):  
Michael Young ◽  
Mohit Kapoor ◽  
Pratibha Chand-Thakuri ◽  
Justin Maxwell ◽  
Daniel Liu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Bond Activation ◽  
Secondary Amines ◽  
Activation Process ◽  
Unified Approach ◽  
Benzylic Amines ◽  
Palladium Catalyzed ◽  
Group A ◽  
Directing Group ◽  
Site Selective

Amines are an important class of compounds in organic chemistry and serve as an important motif in various industries, including pharmaceuticals, agrochemicals, and biotechnology. Several methods have been developed for the C–H functionalization of amines using various directing groups, but functionalization of free amines remains a challenge. Here, we discuss our recently developed carbon dioxide driven highly site-selective γ-arylation of alkyl- and benzylic amines via a palladium-catalyzed C–H bond-activation process. By using carbon dioxide as an inexpensive, sustainable, and transient directing group, a wide variety of amines were arylated at either γ-sp3 or sp2 carbon–hydrogen bonds with high selectivity based on substrate and conditions. This newly developed strategy provides straightforward access to important scaffolds in organic and medicinal chemistry without the need for any expensive directing groups.1 Introduction2 C(sp3)–H Arylation of Aliphatic Amines3 C(sp2)–H Arylation of Benzylamines4 Mechanistic Questions5 Future Outlook

Transition-metal-free site-selective C–F bond activation for synthesis of 8-aminoquinolines

2017 ◽  
Vol 58 (45) ◽  
pp. 4240-4242 ◽  
Author(s):  
Jianping Chen ◽  
Dongyang Huang ◽  
Yuqiang Ding
Keyword(s):  
Transition Metal ◽  
Bond Activation ◽  
Metal Free ◽  
Site Selective

Phosphine-catalyzed remote α-C–H bond activation of alcohols or amines triggered by the radical trifluoromethylation of alkenes: reaction development and mechanistic insights

2017 ◽  
Vol 4 (11) ◽  
pp. 2139-2146 ◽  
Author(s):  
Lei Li ◽  
Liu Ye ◽  
Shao-Fei Ni ◽  
Zhong-Liang Li ◽  
Su Chen ◽  
...  
Keyword(s):  
Bond Activation ◽  
Activation Of Alcohols ◽  
Site Selective

An efficient radical protocol for concomitant functionalization of both alkenes and remote α-C–H bonds of alcohols or amines via 1,5(6,7)-HAT was realized in a highly controlled site-selective manner.

Rh(I)-Catalyzed Enantioselective Cyclization of Enyne through Site-Selective C(sp3)-H Bond Activation Triggered by Formation of Rhodacycle

Synthesis ◽  
2021 ◽  
Author(s):  
Yoshihiro Oonishi ◽  
Shunki Sakamoto ◽  
Shuya Agata ◽  
Yoshihiro Sato
Keyword(s):  
Energy Barrier ◽  
Bond Activation ◽  
High Energy ◽  
Ethyl Group ◽  
High Energy Barrier ◽  
Cyclic Diene ◽  
Key Steps ◽  
Site Selective

Rh(I)-catalyzed enantioselective cyclization of enyne through C(sp3)-H bond activation was investigated. It was found that the cyclization of enyne having a t-butyl moiety on the alkene afforded a spirocyclic compound (up to 92% ee), while the cyclization of enyne having an i-propyl or an ethyl group on the alkene gave a cyclic diene (up to 98% ee). Furthermore, an intermolecular competition reaction using a deuterium-labeled substrate revealed that C(sp3)-H bond activation was one of the key steps, having a high energy barrier, in this cyclization.

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>

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.

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